All the while, the “hybrid athlete” has emerged. Many popular training programs are delivering robust results while combining endurance and strength training together. This hybrid form of training has become the new gold standard in the fitness industry. CrossFit and Hyrox are as popular as ever, and seemingly every influencer has become a shill for “Big Zone-2 Cardio.”

Cardio is cool again, which is cool! But, little attention is being paid to the interference effect – how strength and endurance training affect one another. This article will cover what the interference effect is, what the science says about combining lifting and cardio together, and how to practically apply these concepts to your own training to get the most fitness out of your training.

Defining the Interference Effect of Concurrent Training

The interference effect is defined as reduced strength and/or hypertrophy gains when resistance and endurance training are combined together in the same exercise program. The first use of the term “interference effect” in this context dates back to 1980 when Dr. Robert Hickson showed that untrained men had reduced strength development with concurrent training, or combined strength and endurance training, when compared to resistance training alone.¹

In this view, endurance training “interferes” with the adaptations from resistance training when both forms of exercise are done in the same program.

What explains Dr. Hickson’s findings? And, have those findings been repeated over the last 45 years? Let’s explore some potential mechanisms that explain this effect.

Potential Mechanisms: What Causes the Concurrent Training Interference Effect?

First, some definitions. Exercise is a type of physical activity that is planned, repetitive, and structured with the goal of improving or maintaining health or fitness. Conditioning is an umbrella term that refers to exercise designed to improve endurance performance and cardiorespiratory fitness, both of which rely on the ability of the heart, lungs, and circulatory system (blood vessels) to support muscular function at a given level for a relatively long period of time. In contrast, resistance training is a form of physical activity where muscles create force via contraction against a load, which may be external (barbell) or internal (bodyweight) to the individual to create increases in strength and/or muscular hypertrophy.

Adaptations to exercise are specific to the type of exercise performed. You wouldn’t expect your 1RM squat to increase from an endurance swimming program just like you wouldn’t expect heavy squat training to significantly improve your swimming performance.

Conditioning and resistance training drive different adaptations through different pathways because they are limited by different processes. Aerobic exercise is limited by the cardiovascular and pulmonary systems’ capacity to to supply the working muscle with energy and remove waste products, whereas resistance training is limited by neuromuscular excitability and the ability of the muscle to produce force.

Subsequently, aerobic exercise drives adaptations predominantly concerned with the circulatory system and the working muscles’ ability to extract oxygen, whereas resistance training drives adaptations related to the muscles and associated soft tissues (bones, tendons, ligaments, etc.), as well as the nerves, to improve force production.

Now, there is some overlap between the two, particularly in untrained individuals. If you are starting out with very low levels of fitness, the cardiovascular demands of lifting weights can provide modest improvements in cardiorespiratory fitness.^2,3 Similarly, aerobic training can produce some strength and hypertrophy improvements in the working muscles for people with very low baseline strength levels, though not nearly as well as resistance training. ^4,5

The important thing to note here is that the adaptations made are only what is required. For example, if you were previously sedentary your legs will get stronger from a running program – but only strong enough to support running. Similarly, if you start at low baseline cardiovascular fitness levels then lifting weights will improve your conditioning – but only enough to support lifting weights.

So, how do these different training modalities that produce different fitness adaptations interact or interfere with one another?

Mechanism 1: Competing Signaling Pathways (mTOR vs. AMPK)

The most popular mechanism for an interference effect has to do with competing pathways involved in the body’s response to different types of exercise. For example, many resistance training adaptations depend on activation of the Mammalian Target of Rapamycin (mTOR) pathway to drive increases in muscle protein synthesis (MPS). Increases in MPS are required for building muscle. There is some research that shows inhibition of this pathway when resistance training is combined with aerobic exercise, particularly if cardio is performed prior to resistance training.^6, Additionally, there is data showing that concurrent training may reduce satellite cell signaling, which is involved in muscle remodeling and repair after lifting weights.⁷

Endurance training activates a different metabolic pathway – the AMP-activated protein kinase (AMPK) pathway. When activated, this pathway restores cellular energy balance when intra-cellular ATP levels are lowered. ATP is the high-energy molecule that working muscles use to perform physical activity. After endurance training when large amounts of cellular energy are used to perform the exercise the body activates this pathway to restore energy levels back to resting values.¹³

It is thought that the mTOR pathway and AMPK pathway cannot be active at the same time and they have conflicting effects. Building muscle takes energy, it is an anabolic process. After lifting weights, mTOR is activated and energy goes towards building muscle while we recover from the training session. During and after endurance training. AMPK is activated in an effort to  create energy (ATP) via upregulating catabolic processes, and inhibiting anabolic processes like mTOR.

The goals of these two pathways seem conflicting – if the body is trying to recover from endurance training why would it spend energy on building muscle? This interference of one pathway on another is the crux of the explanation behind Dr. Hickson’s original experiment back in the 1980s. How can the body do two conflicting things at once?

While studying mechanisms can be worthwhile and valuable in the formulation of hypotheses, it is crucial to study the effects of these mechanisms in real humans performing real training programs. Current evidence suggests that the acute activation of AMPK can transiently inhibit mTOR immediately after a workout, but long-term data suggests this effect does not significantly compromise muscle growth when proper recovery and programming are used. This weakens the mechanistic explanation as the primary cause of interference, as discussed in an upcoming section.

Before we get there however, let’s examine another potential mechanism.

Mechanism 2: Total Training Load and Excessive Fatigue

A second mechanism for explaining the interference effect purports that when people add conditioning to their resistance training program, the increase in total training load outstrips their ability to adequately recover. As a result, the training adaptations such as strength, hypertrophy, and muscular power improvements are reduced compared to lifting-only programs.

The fitness-fatigue paradigm states that the larger the training stimulus, the more potential fitness it can create. It also states that the larger the training stimulus, the more fatigue it can generate. So there must always be a balance with total training load. We want a training load that delivers a large stimulus to produce adaptations like hypertrophy, strength, or increased aerobic capacity but we also need to be able to recover from the program.

Let’s say a lifter is currently lifting weights 5 days per week. If they suddenly decide to begin conditioning and try to meet the current physical activity guidelines recommendation of 150 minutes of moderate intensity per week they would be adding a significant chunk of volume to their program. Volume that may exceed their current recovery capacity. In this scenario, the addition of conditioning would certainly lessen results in the immediate to short term.

Training stress and recovery are challenging to measure objectively and can vary significantly from person to person. Training volumes that supersede recovery capacity could be achieved with lifting only and endurance only training programs. In both of those scenarios, you would expect reduced performance due to exceeding recovery capacity. So it is crucial to maintain a training volume that does not cause a reduction in performance.

In this view, the absolute training volume interferes with results – not the metabolic pathways blocking one another.

From a theoretical standpoint, these mechanisms support the interference effect. Could the combination of competing metabolic pathways and a high total workload interfere with gains? 

Better questions are: how big is the interference effect and does it play out in real humans performing real training programs?

For this, we look at the studies performed in humans.

What the Science Says: Is the Concurrent Training Interference Effect Real?

Based on existing data looking at concurrent training versus lifting-only programs, there’s little concern for an interference effect unless total workload exceeds recovery status, particularly for untrained individuals.

Three recent meta-analyses found that concurrent training did not compromise strength or hypertrophy gains significantly when compared to lifting-only programs. ^8,9,12 

Schumann et al. concluded that: “Concurrent aerobic and strength training does not compromise muscle hypertrophy and maximal strength development. However, explosive strength gains may be attenuated, especially when aerobic and strength training are performed in the same session.” ⁹(emphasis added)

With respect to high velocity strength, or power, a more recent study found that concurrent aerobic and strength training does not reduce maximal strength, explosive strength development, or muscle hypertrophy. ¹⁰

Overall, the interference effect originally documented by Dr. Hickson does not appear to show up in long-term training outcome studies. That being said, to maximize fitness adaptations and to ensure that the total workload of a program is both achievable and does exceed recovery capacity some care should be taken.

Concurrent Training in Practice: Lessons from Hybrid Athletes (CrossFit, Hyrox)

Despite evidence demonstrating the lack of interference effect in long term training studies, critics of concurrent training will often state that it will limit your ability to have elite level performances. For example, you will never get as muscular or as strong as possible if you are also trying to improve aerobic capacity.

Let’s use a CrossFit Games competitor as an example of a “hybrid athlete” who does concurrent training at a high level. The 2025 CrossFit games included a 1RM back squat test among 9 other CrossFit workouts over 3 days. The top athlete for the male competitors squatted an impressive 256 kg or 565 pounds and the top female competitor squatted 174 kg or 385 pounds. Many average gym-goers and even some advanced lifters would be envious of these performances.

These are pretty impressive efforts on their own and even more so given that the performance was smack dab in the middle of 9 other workouts that demanded high levels of conditioning and gymnastics skills.

While, yes, these athletes are the top of the sport and most people engaging in CrossFit workouts will not experience this level of performance – their results show that getting strong, building muscle, and improving aerobic capacity are possible concurrently.

But – could they be stronger if they only trained for strength? Or more muscular if they only trained for hypertrophy?

Are these elite CrossFit athletes as absolutely strong as someone their size who trains and competes strictly as an elite level powerlifter? No.

Do these CrossFit athletes have the aerobic capacity of world-class marathon runners? Also, no.

But their performance limitations may not lie in the fact that they are training for several different outcomes at once. The differences in these performances across the different sports likely represents a combination of genetics, time dedicated to achieving one single training outcome, sport selection, and other factors that make freak athletes freak athletes.

Needless to say, the example of these elite CrossFit athletes and other similar athletes demonstrates how it is certainly possible to gain significant amounts of muscle, build significant amounts of strength, and develop great cardiovascular fitness concurrently.

While CrossFit can be a viable way to meet the current Physical Activity Guidelines, not everyone wants to do CrossFit. Present company included. So here are a few practical ways to program resistance training for strength and hypertrophy along with conditioning to meet the current physical activity guidelines and work towards your goals.

Practical Concurrent Training Programming Considerations

The current exercise guidelines recommend performing both aerobic and resistance training.¹¹ This is a reasonable recommendation for the general and athletic population alike. However there is some nuance here as to how the training is applied which can be described using three unique cases relating to training status and goals. Before describing these cases, a brief discussion on training status.

While many folks in the health and fitness space use terms like elite, advanced, intermediate, or novice when describing fitness levels it is very challenging to actually categorize people this way. Broadly speaking, individuals can be classified as either trained or untrained (beginners). After that, categorization becomes really murky and subjective.

For example, it has been suggested that adaptation rate, or how fast someone gets stronger or gains muscle, etc., is a good indicator for training advancement. However, adaptation rates are dynamic in all phases of an individual’s career, and each specific adaptation has a variable rate of advancement – strength vs hypertrophy.  As best as we can tell, strength gain isn’t linear. Rather, strength improvements look more like a staircase, where average strength performance stays about the same for a bit of time, then increases to the next average. On top of that, average strength performance varies within ~5% of a “baseline” day-to-day, making small improvements (or reductions) in strength mostly “noise” vs actual improvements.

People do tend to gain more strength, size, and cardiorespiratory fitness earlier on in their training career as they’re further away from their maximum potential. However, the adaptation rate itself is not static. Newer lifters may go through phases where they’re unable to add weight to the bar or otherwise progressively load their training, and advanced lifters may hit a hot streak and be able to add weight each time they get under the barbell. Because adaptation rate varies in an unpredictable way, it’s not helpful for indicating programming needs. Instead, looking at an individual’s recent training history, their responsiveness to it, current goals, and training resources are more helpful than an arbitrary classification of “intermediate” or “advanced” when it comes to programming. (For more on how-to design and periodize a program, see our 100+ page eBook)

Despite the obvious limitations in any classification system used beyond trained and untrained, these terms do come with a base level of understanding of someone’s training history and fitness level, so we will use some of those terms below.

Case #1: The Untrained Beginner

We would recommend that all untrained beginners engage in concurrent training to meet or exceed the current physical activity guidelines. Existing evidence regarding the interference effect supports this recommendation. Gains in strength, hypertrophy, and muscular power are unlikely to be compromised by adding conditioning to the program as compared to a lifting-only program in this population. This individual engaging in both strength training and conditioning would maximize their health and fitness improvements as there are unique adaptations and benefits to both forms of exercise.

For best results:

• When performing conditioning and resistance training on the same day, conditioning should be performed after resistance training at a moderate intensity, ~ 60-80% max heart rate.
• Ideally, at least 150-minutes of moderate intensity conditioning would be performed weekly, with the volume split as many days as the individual’s preferences, goals, and schedule allows

Case #2: The Competitor

For barbell sport competitors like powerlifters or Olympic weightlifters who are preparing for a meet or strength test, we recommend reducing conditioning volume during the last 4-6 weeks of preparation. Reducing conditioning volume frees up additional training and recovery resources that can be allocated to resistance training, which is the primary goal.

For example, a powerlifter getting ready for a meet who is doing 200-minutes per week of conditioning may reduce their conditioning volume as seen below:

This table clearly illustrates the recommended gradual reduction in conditioning volume (taper) for a strength athlete leading up to a competition.

Making weight, if applicable, would ideally be accomplished ahead of time via dietary interventions and not from excessive sweating and water loss from high levels of conditioning.

Case #3 – The Intermediate

For “intermediates” who are strength-focused, there may be some reticence to adding conditioning to their training at a volume consistent with the current guidelines. These individuals may be at or near their maximum tolerable training load, where adding additional exercise could compromise recovery and subsequent performance. In this case, we recommend a more gradual addition of conditioning in order to minimize any apparent interference effect, even if transient but also maximize fitness and health benefit.

This case describes many lifters who likely double the minimum recommendation of 2 days/week of strength training but don’t perform any conditioning. For this individual, we recommend the following progression that builds up to the minimum recommendation of 150 minutes/week of moderate intensity conditioning volume:

This progression allows the individual to gradually build up to the minimum recommended 150 minutes/week of moderate-intensity conditioning to maximize health benefits while minimizing the risk of an interference effect due to excessive fatigue.

It is important to note that we don’t have anything against running or swimming. Context is important however, as this specific example is a “strength-focused” individual who has not previously been doing a significant amount of conditioning work. Both running and swimming seem to produce a bit more fatigue than other options like cycling, erging, and elliptical-ing, though this is mostly based on experience, not scientific evidence.

Want to know more about conditioning zones, heart rates, and more information regarding conditioning intensity? See here.

Does the Type of Conditioning Matter?

Not every cardio modality is created equally, and they may stress your body in different ways. Swimming, cycling, rowing, and running can be used to achieve your conditioning goals but may fit into your resistance training differently.

One review on the topic found that while the interference effect was small and possibly isolated to Type I fibers that experience less hypertrophy compared to Type II fibers, the effect was more pronounced with running programs as compared to cycling programs.¹²

Other studies, however, came to the opposite conclusion. They found that cycling had a larger negative effect than running with lower body exercise performance and muscle gain.¹⁴

The evidence doesn’t provide any strong indication to choose one cardio modality over another. We would encourage folks to choose a conditioning modality that aligns with your goals, preferences, and equipment access while paying mind to the overall training load as too large of a dose of conditioning could interfere due to accumulating levels of fatigue.

Wrap-Up

The interference effect is defined as reduced strength, size, and/or power gains when doing both aerobic and resistance training as compared to a lifting-only program. While many potential mechanisms have been suggested, the existing evidence suggests that any apparent interference effect is transient, likely being related to an over-zealous training load.

A good training program to support health and fitness will include both conditioning and strength training elements, though the proportion of each as part of the total training load will vary over time based on individual factors. For more strength-focused individuals, the bulk of the training load will be allocated to resistance training, with just enough left over to do conditioning that meets the current guidelines.  For endurance-focused individuals, the bulk of the training load will be allocated to conditioning, with a smaller proportion achieved from lifting in order to support musculoskeletal function and reduce injury risk. For non-specialized individuals, the distribution of training load is mostly personal preference, though it should include both conditioning and resistance training.

References

1. Hickson R. C. (1980). Interference of strength development by simultaneously training for strength and endurance. European journal of applied physiology and occupational physiology, 45(2-3), 255–263. https://doi.org/10.1007/BF00421333
2. Mang, Z. A., Ducharme, J. B., Mermier, C., Kravitz, L., de Castro Magalhaes, F., & Amorim, F. (2022). Aerobic Adaptations to Resistance Training: The Role of Time under Tension. International journal of sports medicine, 43(10), 829–839. https://doi.org/10.1055/a-1664-8701
3. Ozaki, H., Loenneke, J.P., Thiebaud, R.S. et al. Resistance training induced increase in VO2max in young and older subjects. Eur Rev Aging Phys Act 10, 107–116 (2013). https://doi.org/10.1007/s11556-013-0120-1
4. Konopka, A. R., & Harber, M. P. (2014). Skeletal muscle hypertrophy after aerobic exercise training. Exercise and sport sciences reviews, 42(2), 53–61. https://doi.org/10.1249/JES.0000000000000007
5. Konopka, A. R., Douglass, M. D., Kaminsky, L. A., Jemiolo, B., Trappe, T. A., Trappe, S., & Harber, M. P. (2010). Molecular adaptations to aerobic exercise training in skeletal muscle of older women. The journals of gerontology. Series A, Biological sciences and medical sciences, 65(11), 1201–1207. https://doi.org/10.1093/gerona/glq109
6. Rose, A. J., Broholm, C., Kiillerich, K., Finn, S. G., Proud, C. G., Rider, M. H., Richter, E. A., & Kiens, B. (2005). Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men. The Journal of physiology, 569(Pt 1), 223–228. https://doi.org/10.1113/jphysiol.2005.097154
7. Babcock, L., Escano, M., D’Lugos, A., Todd, K., Murach, K., & Luden, N. (2012). Concurrent aerobic exercise interferes with the satellite cell response to acute resistance exercise. American journal of physiology. Regulatory, integrative and comparative physiology, 302(12), R1458–R1465. https://doi.org/10.1152/ajpregu.00035.2012
8. Petré, H., Hemmingsson, E., Rosdahl, H., & Psilander, N. (2021). Development of Maximal Dynamic Strength During Concurrent Resistance and Endurance Training in Untrained, Moderately Trained, and Trained Individuals: A Systematic Review and Meta-analysis. Sports medicine (Auckland, N.Z.), 51(5), 991–1010. https://doi.org/10.1007/s40279-021-01426-9
9. Schumann, M., Feuerbacher, J. F., Sünkeler, M., Freitag, N., Rønnestad, B. R., Doma, K., & Lundberg, T. R. (2022). Compatibility of Concurrent Aerobic and Strength Training for Skeletal Muscle Size and Function: An Updated Systematic Review and Meta-Analysis. Sports medicine (Auckland, N.Z.), 52(3), 601–612. https://doi.org/10.1007/s40279-021-01587-7
10. Feuerbacher, J.F., Jacobs, M.W., Heumann, P., Pareja-Blanco, F., Hackney, A.C., Zacher, J. and Schumann, M. (2025), Neuromuscular Adaptations to Same Versus Separate Muscle-Group Concurrent Aerobic and Strength Training in Recreationally Active Males and Females. Scand J Med Sci Sports, 35: e70025. https://doi.org/10.1111/sms.70025
11. Piercy, K. L., Troiano, R. P., Ballard, R. M., Carlson, S. A., Fulton, J. E., Galuska, D. A., George, S. M., & Olson, R. D. (2018). The Physical Activity Guidelines for Americans. JAMA, 320(19), 2020–2028. https://doi.org/10.1001/jama.2018.14854
12. Lundberg, T. R., Feuerbacher, J. F., Sünkeler, M., & Schumann, M. (2022). The Effects of Concurrent Aerobic and Strength Training on Muscle Fiber Hypertrophy: A Systematic Review and Meta-Analysis. Sports medicine (Auckland, N.Z.), 52(10), 2391–2403. https://doi.org/10.1007/s40279-022-01688-x
13. Spaulding, H. R., & Yan, Z. (2022). AMPK and the Adaptation to Exercise. Annual review of physiology, 84, 209–227. https://doi.org/10.1146/annurev-physiol-060721-095517
14. Sabag, A., Najafi, A., Michael, S., Esgin, T., Halaki, M., & Hackett, D. (2018). The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis. Journal of sports sciences, 36(21), 2472–2483. https://doi.org/10.1080/02640414.2018.1464636

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Understanding Concussion: How It Affects the Brain

The brain is suspended and cushioned inside the skull by specialized connective tissues called meninges. It is further protected by a liquid called cerebrospinal fluid. During a significant head impact, the brain can collide with the skull, which is known as an “acceleration-deceleration” injury.

The Physiology of an Acceleration-Deceleration Injury

The acceleration-deceleration injury mechanism is related to the change in the velocity of the head. This can happen when a moving object hits a stationary head (acceleration) or when a moving head hits a stationary object (deceleration).  One specific type of acceleration-deceleration injury that is often taught to students is a coup-countercoup injury, where the brain is thrown forward and strikes the inside of the skull (coup), and then rebounds and strikes the opposite side of the brain(contrecoup). 

Concussions can cause brain bruising (known as a contusion) and other structural changes, most early symptoms result from changes in brain function, not structural damage. The forces that cause the brain to shift in the skull stretch the nerves in your brain, triggering inflammation, swelling and release of chemical signals. These cause your brain to burn more energy in an effort to restore normal function.

Concussion Symptoms: What to Look For

​​Diagnosis of a concussion relies on the presence of one or more characteristic symptoms. A common myth is that you need to “pass out” to have a concussion. This is not true. A concussion can result from any significant head injury, regardless of whether you lose consciousness. 

Common symptoms after a head injury with or without loss of consciousness can include:

• Memory loss and confusion (most common)
• Headache
• Dizziness
• Nausea and vomiting
• Difficulty balancing and walking
• Difficulty with focus
• Mood and behavior changes
• Difficulty sleeping or excessive fatigue
• Light and sound sensitivity
• Vacant stare
• Delayed verbal response

Not all head impacts cause concussions, although these symptoms can sometimes result from seemingly minor injuries. Being aware of them and monitoring their severity can help determine if seeking medical care is warranted.

When to Seek Urgent Medical Care For Concussion: Red Flag Symptoms

The following features are associated with a higher risk of more serious injury, compared with an uncomplicated concussion that is likely to resolve on its own. These are especially serious when the person is 60 years or older, or when the person is taking blood thinning medications due to increased risk of bleeding in the brain.

• Limb weakness or tingling/burning in an arm or legs
• Vision loss or double vision (not just “blurred”)
• Abnormally large, small, or asymmetrical pupils
• Seizures (occur in less than 5% of concussions)
• Loss of consciousness greater than 1 minute
• Persistent alteration in mental status
• Skull fracture
• More than 2 episodes of vomiting
• Amnesia extending beyond 30 minutes before the injury
• Severe or increasing headache
• Increasing restless, agitated or combative behavior
• Neck pain or tenderness

If someone is experiencing any of these symptoms, seek immediate, urgent medical attention.

How Medical Professionals Diagnose a Concussion

A concussion can be diagnosed in a person after a significant head injury, who has neurological symptoms including confusion, memory loss, or others as described above, regardless of loss of consciousness. In addition to a neurological evaluation, you may see healthcare professionals use standardized exams to evaluate for concussion. 

The Role of Standardized Exams: The SCAT6

The Sport Concussion Assessment Tool 6 (SCAT6) is very commonly used for assessment of potential on-field concussions in the acute setting. The SCAT6 evaluates patient history and risk factors, red flag signs, symptoms of concussion, and examines level of consciousness, the cervical spine (neck), coordination, eye movement, memory, There are several other standardized examinations used by healthcare professionals that are outside the scope of this article.

Concussion Recovery: The Modern Approach to Treatment

Most routine concussions without any concerning red flag signs can be managed with outpatient observation and symptomatic treatment. Follow-up attention should be sought if any new red flag symptoms develop later on.

Recovery Timeline: What to Expect

If there are no complications, people tend to experience the most significant symptoms for 7–10 days after injury, with most symptoms completely resolving by 1–3 months after injury. Some people experience symptoms longer than 3 months, known as “persistent post-concussion syndrome”. There are several important considerations during this period.

The Importance of “Relative Rest” vs. Absolute Rest

Previous recommendations for concussion recovery involved long periods of “absolute” rest. Unfortunately, prolonged rest turned out to be associated with increased symptoms after concussion. As a result, we currently suggest a period of 24 to 48 hours of “relative” rest after an uncomplicated concussion.

Rather than “absolute” rest, the goal of this relative rest period is to maintain as much of a person’s regular activities of daily life as possible without causing significant worsening of their symptoms. While short-term modifications may be necessary, maintaining activity levels and decreasing screen time is beneficial, especially during the first 48 hours after injury. If activity must be reduced, rest should not lead to an increase in screen time. As long as it does not cause significant worsening of symptoms, light aerobic activity such as walking can safely be started within the relative rest period, and will likely help with recovery. While people vary in their response to napping, minimizing daytime naps may increase the chances of getting sufficient quantity and quality of sleep at night.

Preventing Re-Injury During Recovery and Supportive Measures

Avoid activities with risk for head impact and another concussion. A second injury during healing from the initial injury can lead to more serious brain injury.

Avoid the use of other substances such as alcohol and cannabis during recovery. Depending upon someone’s medical history, oral pain medicines like acetaminophen or non-steroidal anti-inflammatories can be used within recommended dosing guidelines as needed. While significant dehydration is not common in general, maintaining adequate hydration is important for brain function as well.

Return to Play: A Phased Guide for Athletes

Recovery from many injuries starts with rest or modified activity, followed by imposing gradually increasing demands while monitoring symptoms, and then proceeds to recovery where function continues to improve. Recovery is best accomplished with the guidance of qualified clinicians, but a degree of self-management is often necessary, and the steps below provide a practical framework.

This sample progression imagines a mild concussion for a participant in a contact sport, where returning to normal activity levels in approximately one week might be appropriate. There are seven stages. After the initial 24–48 hour period of stage one, subsequent stages should last a minimum of 24 hours. After each stage, self-assessment is required to determine how well the advancing activity levels were tolerated.

If increased activity exacerbates symptoms for greater than 1 hour, OR if medications are needed to treat the severity of symptoms, do not proceed to the next stage and consider reducing the intensity of activity.

Stage 1: Relative Rest and Return to Non-Sport Daily Activity

​​The goal of this phase is to allow the brain to recover and to avoid exacerbating symptoms for 24 to 48 hours after the injury. Engaging in light general activity while avoiding excess strain is fine, with walks being preferred. Rest may be required if subjective symptoms are worse than 7/10. Limiting screen time is recommended.

Stage 2: Light Aerobic Activity

Introduce more deliberate exercise with steady state aerobic exercises such as faster walking, swimming, or stationary bike as options, among others. Heart rate should be kept below 55% of maximum.

Stage 3: Moderate Aerobic Activity & Light Resistance Training

Gradually increase exercise intensity and complexity. Heart rate should be kept below 70% of maximum. This is also the time to resume light resistance training; intensity should be limited by tolerance and symptoms. Medical clearance should be obtained prior to progression to Stage 4 if the increase in sport-specific training involves risk of head impact.

Stage 4: Sport-Specific Exercise

Aerobic activity can be progressed based on tolerance into higher intensity ranges. Some lower-intensity sport-specific exercises and conditioning drills can be reintroduced, as long as head impacts are avoided. Performing individual drills outside of the team environment can minimize the risk of accidental impacts.

Stage 5: Non-Contact Practice

The intensity of sport-specific and ball handling drills in the team environment can be increased along with more demanding coordination tasks. More intense conditioning can be pursued, although impacts and other jarring contacts should still be avoided. Strength training and aerobic exercise can be resumed at previous intensities as tolerated.

Stage 6: Full-Contact Practice

Before resuming full-contact practice, consulting with a clinician to get medical clearance is advised. If symptoms allow, normal practice, including contact, can start again.

Stage 7: Return to Play

At this point, symptoms should have dissipated to the point that largely unrestricted functioning, including participation in competition is appropriate. Some continued caution is warranted to avoid re-injury.

Complications and After-Effects of Concussions

Re-Injury Risk

One of the most common concerns after a concussion is suffering another one. Premature return to play in athletes increases risk of re-injury. This most commonly happens within the first 7–10 days of the initial insult. Those who participate in contact sports require particular caution, since risk increases with each subsequent concussion. For example, 1 in 15 college football athletes who experienced their first concussion had a second concussion during the same season. A history of three concussions triples your risk of having another concussion in the future.

Repeated Head Impacts and CTE

While we do not have a clear consensus around the condition known as “chronic traumatic encephalopathy” (CTE), a neurodegenerative disease, we do observe that repeated concussions can lead to cognitive impairment, psychiatric symptoms, increased risk of dementia, and disorders of movement, gait and speech. This most commonly happens in military personnel and athletes participating in contact sports. 

Post-Concussion Syndrome (PCS)

Longer-lasting conditions such as “Post-Concussive syndrome” (PCS) or “Symptoms Persisting After Concussion” are a risk for a minority of people injured: while over 30% of those who experience a concussion will experience lingering symptoms beyond 1 month, “Post-concussive syndrome” specifically describes symptoms lasting more than three months after the initial injury. Further, about 15% of patients who develop Post Concussive Syndrome experience symptoms lasting beyond one year. The most common symptoms include headaches, sleep disturbances, dizziness, fatigue, irritability, anxiety, forgetfulness, noise sensitivity, but may include other symptoms as well.

Persistent symptoms beyond 1 month should be evaluated by a physician, and often require brain MRI scans and/or neuropsychological testing. Treatment depends on symptoms and the results of medical evaluation. Specific medications and psychotherapy can target symptoms such as headache, mood and sleep disturbances. Education and reassurance are essential, given that these effects are common and people can still have a good prognosis for recovery.

Concussion Myths and Unproven Treatments

​​Before considering treatments that lack strong supporting evidence, first prioritize the best practices outlined above. This involves adequate high-quality sleep, eating a health-promoting diet, maintaining adequate hydration, modifying physical and cognitive stress based on tolerance, and seeking expert medical care. Other proposed treatments exist, and many of them are best avoided.

The Harm of Prolonged Rest

Medical practitioners who are out of date with current evidence may suggest prolonged or absolute rest. Prolonged rest beyond 24 to 48 hours should be avoided unless absolutely necessary for symptom control, as longer rest periods lead to worse symptom intensity and duration.

Treatments Lacking Evidence (Hyperbaric Oxygen, Neurofeedback, Blue-Light Lenses)

The Internet provides a variety of recommendations for concussion recovery. Some may have shown small benefits in single studies, but often lack more robust, reliable evidence.

Hyperbaric oxygen therapy research is inconsistent and filled with significant flaws and biases. These treatments often cost thousands of dollars, and the current research does not show substantial, reliable evidence of benefit in recovery.

Neurofeedback and Transcranial Magnetic Stimulation are being studied for reducing post-concussive headache and depression; however, this is another expensive treatment ($300–500 per session) that has not shown consistent benefit, and cannot be strongly recommended to facilitate recovery.

Blue-light blocking lenses have not been studied for concussion recovery, but initial studies show no benefit on visual fatigue scores in otherwise healthy individuals, and are unlikely to provide a substantial benefit in recovery.

Supplements (Creatine, Electrolytes)

Creatine has not been explicitly studied for concussion recovery. Currently, any evidence of benefit in this context is based on the extrapolation of mechanistic data or indirect outcomes from smaller studies. While creatine has established benefits in many other contexts, it has not yet been convincingly shown to be of benefit for concussions.

Electrolyte supplementation (including sodium, potassium, calcium, magnesium or phosphate) has not shown clear benefits on concussion recovery, unless you are deficient or struggle to meet your daily nutrient needs through regular consumption.

Key Takeaways on Concussion Recovery

A concussion is a functional brain injury that can result from any significant head impact, even without a loss of consciousness. While common symptoms like headaches, dizziness, and confusion often resolve within weeks , it is critical to watch for “red flag” symptoms that require immediate medical attention. Modern recovery emphasizes a 24 to 48-hour period of “relative rest” rather than prolonged rest, which can actually worsen symptoms. Following this initial period, a gradual, staged return to daily life and exercise is the cornerstone of successful recovery , prioritizing the prevention of re-injury and avoiding unproven treatments. 

Edited by Derek Miles, DPT, Thomas Campitelli, Austin Baraki, MD, FACP

References

• Ainsley Dean PJ, Arikan G, Opitz B, Sterr A. Potential for use of creatine supplementation following mild traumatic brain injury. Concussion. 2017 Mar 21;2(2):CNC34. doi: 10.2217/cnc-2016-0016. PMID: 30202575; PMCID: PMC6094347.
• Centers for Disease Control and Prevention (CDC). Returning to Sports [Internet]. HEADS UP; 2025 Sept 15. Available from: https://www.cdc.gov/heads-up/guidelines/returning-to-sports.html
• Corrigan JD, Selassie AW, Orman JA. Traumatic brain injury: epidemiology, classification, and pathophysiology [UpToDate online]. UpToDate; last updated May 13, 2024. Accessed Oct 20, 2025. https://www.uptodate.com/contents/traumatic-brain-injury-epidemiology-classification-and-pathophysiology?search=concussion&topicRef=4828&source=see_link
• Echemendia RJ, Brett BL, Broglio SP, Davis GA, Giza CC, Guskiewicz KM, Harmon KG, Herring SA, Howell DR, Master CL, McCrea M, Naidu D, Patricios JS, Putukian M, Walton SR, Schneider KJ, Burma JS, Bruce JM. Sport Concussion Assessment Tool-6 (SCAT6). Br J Sports Med. 2023;57(11):622-631. doi:10.1136/bjsports-2023-107036.
• Evans RW, Whitlow CT. Acute mild traumatic brain injury (concussion) in adults [UpToDate online]. UpToDate; last updated Feb 22 2022. Accessed Oct 20 2025. https://www.uptodate.com/contents/acute-mild-traumatic-brain-injury-concussion-in-adults (UpToDate)
• Evans RW, Furman JM. Postconcussion syndrome [UpToDate online]. UpToDate; last updated [accessed Oct 20 2025]. Available at: https://www.uptodate.com/contents/postconcussion-syndrome?search=postconcussion%20syndrome&source=search_result&selectedTitle=1~21&usage_type=default&display_rank=1
• GBD 2016 Traumatic Brain Injury and Spinal Cord Injury Collaborators. Global, regional, and national burden of traumatic brain injury and spinal cord injury, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2019 Jan;18(1):56-87. doi: 10.1016/S1474-4422(18)30415-0. Epub 2018 Nov 26. Erratum in: Lancet Neurol. 2021 Dec;20(12):e7. doi: 10.1016/S1474-4422(21)00383-5. PMID: 30497965; PMCID: PMC6291456.
• Harch PG. Systematic review and dosage analysis: hyperbaric oxygen therapy efficacy in mild traumatic brain injury persistent postconcussion syndrome. Front Neurol. 2022;13:815056. doi:10.3389/fneur.2022.815056 (frontiersin.org)
• Krainin BM, Seehusen CN, Smulligan KL, Wingerson MJ, Wilson JC, Howell DR. Symptom and clinical recovery outcomes for pediatric concussion following early physical activity. J Neurosurg Pediatr. 2021 Sep 24;28(6):623-630. doi: 10.3171/2021.6.PEDS21264. PMID: 34560641.
• Macnow T, Curran T, Tolliday C, Martin K, McCarthy M, Ayturk D, Babu KM, Mannix R. Effect of Screen Time on Recovery From Concussion: A Randomized Clinical Trial. JAMA Pediatr. 2021 Nov 1;175(11):1124-1131. doi: 10.1001/jamapediatrics.2021.2782. PMID: 34491285; PMCID: PMC8424526.
• McMillan P, Makrai E, Lawrenson JG, Hull CC, Downie LE. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database Syst Rev. 2023 Aug 18;8(8):CD013244. doi: 10.1002/14651858.CD013244.pub2. PMID: 37593770; PMCID: PMC10436683.
• Mollica A, Safavifar F, Fralick M, Giacobbe P, Lipsman N, Burke MJ. Transcranial magnetic stimulation for the treatment of concussion: a systematic review. Neuromodulation. 2021;24(5):803-812. doi:10.1111/ner.13319 (PubMed)
• Patricios JS, Schneider KJ, Dvorák J, et al. Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport–Amsterdam, October 2022. Br J Sports Med. 2023;57(11):695-711. doi:10.1136/bjsports-2023-106898 (bjsm.bmj.com)Singh S, Keller PR, Busija L,
• Tran V, Flores J, Sheldon M, Pena C, Nugent K. Fluid and Electrolyte Disorders in Traumatic Brain Injury: Clinical Implications and Management Strategies. J Clin Med. 2025 Jan 24;14(3):756. doi: 10.3390/jcm14030756. PMID: 39941427; PMCID: PMC11818519.
• Wolf C, Fast K. “Put Me Back In, Coach!” Concussion and Return to Play. Mo Med. 2017 Jan-Feb;114(1):36-39. PMID: 30233098; PMCID: PMC6143567.

The post What is a Concussion? A Guide to Symptoms, Treatment, and Recovery appeared first on Barbell Medicine.

Whether you’ve been working out for years or are just starting, you’ve likely seen the term “progressive overload” billed as a foundational concept in exercise. It’s the magic bullet, the secret sauce, the one universal truth that every coach and trainer agrees is necessary for making progress.

What they don’t agree on, however, is what it actually means.

In our previous article on this topic, we suggested that the term “progressive overload” is often misunderstood and that “progressive loading” is a more accurate and useful concept. Still, there’s more to discuss to provide true clarity on how to apply these principles to get the best results from your training.

The Origin of Progressive Overload

The term “progressive overload” is widely credited to Dr. Thomas DeLorme, an army physician in the 1940s ¹. He was tasked with a practical problem: how to rehab his orthopedic patients faster to free up hospital beds. Necessity being the mother of invention, DeLorme’s approach was revolutionary at the time, especially in medicine.

Rather than light, high-rep exercise, he used progressively heavier weights to rehab his patients. There’s a story of his wife, Eleanor, coining the term “progressive overload” to describe his method in a way that wouldn’t alarm other doctors who would likely be skeptical of the term “heavy resistance exercise” that DeLorme used ¹. 

A notable case was Sergeant Walter Easley, who tore his ACL and MCL in both knees during a parachute jump. DeLorme had Easley use “iron boots,” a product from York Barbell, and perform 7 sets of 10 repetitions. Easley was instructed to increase the weight once he “mastered the weight for the 7 sets of 10.”  This notion of increasing resistance only after demonstrated mastery and improved function is the critical original insight, later published in DeLorme’s 1951 book, Progressive Resistance Exercise: Technique and Medical Application ¹. 

The core idea from DeLorme was simple: gradually increase the resistance as the patient got stronger and more capable. This seems far removed from the overly complicated and sometimes contradictory definitions we see today.

What Progressive Overload Is (and Isn’t)

Many organizations like the ACSM and coaches define progressive overload as “the gradual increase of stress placed upon the body” ². While this sounds right on the surface, it’s a poor definition because it confuses two critical, yet distinct, concepts: training stimulus and training stress. 

• Training Stimulus (External Load): This is the physical work performed by the individual, i.e. what’s applied “externally”. In a training plan, it’s the weight on the bar, the specific number of reps, the total distance you run, or the total number of sets you perform. Think of this as the input variable you directly manipulate in your program.

• Training Stress (Internal Load): This is what’s going on inside the body in response to the training performed. Some of the psychological and physiological responses can be directly measured, e.g. changes in heart rate and heart rate recovery. Other internal processes are best assessed using proxies such as Rate of Perceived Exertion (RPE), subjective feelings of fatigue, soreness, and motivation, among others ³.

For completeness, the NSCA defines progressive overload as “the systematic modification of a training program over time… and increasing the difficulty of exercise selection” ⁴. Neither of these are consistent with the concept or implementation of progressive overload. Instead, the systemic modification of training over time is periodization, whereas exercise selection is a programming variable not directly related to altering training stress. 

In any case, the biggest error when it comes to defining and understanding progressive overload is that it means an “increase in training stress”. It does not. Instead, the purpose of progressive overload is to maintain a similar, productive level of training stress over time to facilitate long-term adaptation. As your fitness improves (you get stronger or fitter), your body becomes more capable. Therefore, you need to apply a greater training stimulus (more weight/reps/sets) to elicit the same training stress you used to get from your training.

Conversely, if your fitness temporarily decreases (due to a lack of sleep, poor nutrition, or illness), you might need a lower training stimulus to produce the appropriate, more tolerable amount of stress. 

The key insight is that training should not be a constant game of “how much more stress can I add?” but rather “how do I apply the right stimulus to maintain the correct amount of stress and keep making progress?” This dynamic, adaptable philosophy is the key to correctly implementing progressive overload.  

Defining and Measuring Progress

So, if we aren’t just blindly adding weight, how do we know we’re progressing?

In resistance training, real progress is about demonstrating a higher level of performance under the same circumstances. For example, an improvement in strength could be an increase in the amount of weight lifted for a given number of reps, using the same range of motion and effort level. If an individual added 5-lbs to the bar, but squatted the reps high, that would not represent an increase in strength anymore than adding weight and the effort increasing markedly (e.g. from RPE 8 to 10). 

We can refine our understanding of strength progress further by stealing a concept from medicine known as the Minimal Clinically Important Difference or MCID. For strength, the MCID is the amount of strength change that is large enough that it is unlikely to be due to mere measurement error or natural day-to-day fluctuations.

For example, we know that a tiny 0.5% increase in your 1RM (estimated or directly measured) is likely just noise, perhaps due to better sleep or motivation that day. A 10% improvement, however, is a clear sign of real, lasting muscular and neurological progress. We’ve found that a 5% change in strength likely is a reasonable MCID threshold. In other words, when strength performance goes up or down by ~5% or more, that’s likely real and not an artifact. 

However, the time course for strength improvements that meet or exceed the MCID varies amongst individuals based on their training experience, response to a given program, how strength is assessed, and other factors like nutrition, sleep, motivation, to name a few.

Interestingly, research shows that strength gains are not linear and do not occur on timescale often described. A comprehensive review of 40 resistance-training studies found that, on average, it took 4.3 weeks for a demonstrable increase in strength to appear. The individual variation was large, with the range spanning from 1 to 12 weeks ⁵. Some of this variation is due to the variation in how individuals respond to a program, as well as the methods and frequency for assessing strength performance. Still, most people will not be able to improve strength every week, let alone every few days. Real strength gains take a bit longer to be developed. 

There are some important implications of this finding both relating to mismatch between expectations and reality.  By incorrectly assuming that progress should be made in a predictable, linear, and rapid manner, many lifters may be giving up on their programs too soon if they can’t add weight to the bar weekly (or faster). They assume that a plateau has been hit when in reality, they just need to stay the course until their gains are realized and become statistically significant. Additionally, attempting to add weight each week (or faster) is generally inconsistent with the time course of strength gains. Adding too much training stimulus can produce too much training stress and generate excess fatigue, which can overwhelm an individual’s recovery resources, leading to slowed progress and an increased risk of injury.

When and How-To Add Weight

The weight on the bar is simply a tool to stimulate the musculoskeletal and neuromuscular systems. Provided the weight is heavy enough to produce the desired adaptations, e.g. improved coordination and muscular force production, an individual is likely to get stronger so long as the dose (volume) of training is appropriate. For maximal strength, this generally means staying above ~70% of your 1RM ⁶ for multi-rep sets and 85% for single-rep sets ⁷ (which are more skill-focused).

This means that there is a relatively wide range of “viable” training intensities to improve strength, with similar results being generated by using loads contained therein. Practically speaking, we don’t have to add weight constantly to get stronger, but we do need to add it periodically to ensure we don’t fall “out” of the appropriate intensity range necessary for continued adaptation. 

Here are three practical, coach-tested strategies for when and how to add load:

1. The “Aggressive” Approach: Use a “marker” warm-up weight to gauge your readiness for the day. If that marker set feels lighter and faster than it did in the previous session, you have evidence that you can push the top sets heavier. This approach is most effective during periods of high resource availability (great sleep, solid nutrition, low life stress) and can allow an individual to demonstrate strength improvements as fast as they come online. However, because it relies heavily on day-to-day fluctuations, it also carries a higher risk of overshooting your actual capacity and prematurely accumulating unwanted fatigue if you get it wrong, potentially leading to an eventual abrupt plateau.

2. The “Conservative” Approach: Wait for a noticeable, sustained decrease in your Rate of Perceived Exertion (RPE) before increasing the weight. For example, if your sets of 5 have been consistently feeling like an RPE 8 (2 reps left in the tank), wait until they drop to an RPE 7 or RPE 6 for the same weight before increasing the load by a standard increment (e.g., 5 lbs). This is a reliable method that prevents overshooting the target RPE, which can be useful for individuals who are prone to going too heavy, too often. On the other hand, it may feel frustratingly slow for some driven athletes.

3. The “Artificial Momentum” Approach: Start with a weight that is intentionally light (e.g., aiming for an initial RPE 6) and gradually increase the load over a training block (4-6 weeks) so that the same prescribed work (e.g., 5 reps) becomes progressively more challenging (e.g., reaching RPE 8 by the end of the block). This provides a predictable on-ramp and may offer a strong psychological boost from adding weight week-to-week, even if the actual strength gains aren’t occurring at the same rate in which weight is added. With this setup, the final week of the block can serve as an implicit test of progress as compared to previous training cycles.

Although slightly different in execution, each strategy attempts to maintain the correct level of training stress in order to produce the desired fitness adaptations. 

The Power of Double Progression

One programming option that may make it easier to correctly implement progressive overload is double progression, which combines the manipulation of both reps and load for improving muscular adaptations ⁸. This approach offers more flexibility to take advantage of whatever strength adaptation is available—either strength endurance (more reps) or maximal strength (more load)—and helps build momentum by providing a clear, short-term goal for every training session.

For example, you might be programmed to perform a set of squats for “4 to 6 reps at RPE 8.”In this scenario, you’re aiming to reach the top of the rep range (6 reps) at the prescribed effort level (RPE 8) before increasing the weight. This provides a built-in “runway” for strength adaptations to occur.  Once you successfully hit your target of 6 reps at RPE 8, you increase the load and reset the goal back to at least 4 reps at the new, heavier weight. After building some capacity, it is unlikely the individual will “fall out” of the prescribed rep range with the new, heavier weight. 

Using this approach his method can be superior to fixed-rep approaches, especially when dealing with exercises where the load jumps are large, e.g. dumbbell, unilateral, and/or machine work.

Troubleshooting the Plateau

Even with a perfectly executed progressive overload strategy, plateaus will happen. We define a plateau as an arbitrary line where a coach would say, “you haven’t seen a demonstrable improvement in a while.” For a relatively untrained individual, this might be 2-3 weeks. For a highly trained lifter, it could be extended to 5-6 weeks. Continuing a program beyond these timeframes without any improvement increases the likelihood of reduced long-term progress, whereas shortening the timeframe can lead to unnecessary program-hopping. 

When a plateau hits, your first step is a simple assessment of recent training history and environment:

• Was the program working well before tapering off? If so, you likely need to increase the training dose. This means increasing volume (adding more sets) via increased training frequency (adding sessions) and/or more exercises for a specific movement pattern, while keeping the average intensity and proximity to failure about the same. You’re simply increasing the total training load in order to increase training stress back to a productive level.
• Was the program not working well from the start? In this case, both the training dose and the program’s formulation are on the table. You must check the environmental inputs first: Are they sleeping well? Is nutrition adequate? If environmental inputs are poor, consider lowering the training load while maintaining the formulation (a small deload is often warranted here). If the environment is mostly fine, consider adding training load while simultaneously reformulating the program, e.g. swapping the exercises, adjusting the RPE targets, or shifting the focus of the rep ranges to better target the desired adaptation.

Remember, every program eventually needs to be adjusted over time. The key is knowing how and when to make the correct changes for the individual. For more on troubleshooting plateaus, check out the 100+ page ebook on programming that accompanies the Low Fatigue Template. 

Final Takeaway

Overall, the foundational exercise concept of progressive overload is often misunderstood and poorly defined, leading to suboptimal results and premature plateaus. To correctly implement progressive overload, we recommend keeping the following points in mind:

• Increases in strength allow you to progress. As an individual gets fitter, a greater stimulus (more weight/reps) is needed to produce the same stress and continue making progress.  If fitness decreases, a lower stimulus would be needed.
• Strength performance varies day-to-day. Depending on biological, psychological, and environmental inputs, strength ebbs and flows between a “floor” and a “ceiling”, creating an average strength level. 
• Strength gains are not linear. Strength adaptations occur due via updates to both muscular (hardware) and neurological (software) systems over time. With intelligent programming and continued training, an individual’s average floor, ceiling, and average strength should increase over time. 
• Plateaus are common, but interpreting them can be tricky. Plateaus in training represent a state where demonstrable progress has not been seen after an extended amount of time. Determining whether the plateau is due to too much training stress or not enough requires a deeper investigation relating to recovery, previous success (or not) with the program, and the individual’s experience.

Thanks for reading. See you in the gym!

References

1. Todd, Janice S et al. “Thomas L. DeLorme and the science of progressive resistance exercise.” Journal of strength and conditioning research vol. 26,11 (2012): 2913-23. doi:10.1519/JSC.0b013e31825adcb4
2. American College of Sports Medicine. “American College of Sports Medicine position stand. Progression models in resistance training for healthy adults.” Medicine and science in sports and exercise vol. 41,3 (2009): 687-708. doi:10.1249/MSS.0b013e3181915670
3. Impellizzeri, Franco M et al. “Internal and External Training Load: 15 Years On.” International journal of sports physiology and performance vol. 14,2 (2019): 270-273. doi:10.1123/ijspp.2018-0935
4. National Strength and Conditioning Association. Foundations of Fitness Programming. National Strength and Conditioning Association, 2015.
5. Lambrianides, Yiannis; Epro, Gaspar; Smith, Kenton; Mileva, Katya N.; James, Darren; Karamanidis, Kiros. Impact of Different Mechanical and Metabolic Stimuli on the Temporal Dynamics of Muscle Strength Adaptation. Journal of Strength and Conditioning Research 36(11):p 3246-3255, November 2022. | DOI: 10.1519/JSC.0000000000004300
6. Schoenfeld, Brad J et al. “Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training: A Systematic Review and Meta-analysis.” Journal of strength and conditioning research vol. 31,12 (2017): 3508-3523. doi:10.1519/JSC.0000000000002200
7. Androulakis-Korakakis, Patroklos et al. “Reduced Volume ‘Daily Max’ Training Compared to Higher Volume Periodized Training in Powerlifters Preparing for Competition-A Pilot Study.” Sports (Basel, Switzerland) vol. 6,3 86. 29 Aug. 2018, doi:10.3390/sports6030086
8. Plotkin, Daniel et al. “Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations.” PeerJ vol. 10 e14142. 30 Sep. 2022, doi:10.7717/peerj.14142

The post Beyond Progressive Overload: Work Smarter, Not Harder appeared first on Barbell Medicine.

It’s well understood that in order to reach certain fitness goals or weight management outcomes a particular diet should be followed. For example, a dietary pattern that creates a Caloric deficit is required to achieve weight loss. Euphemisms like “abs are made in the kitchen” and “you can’t out train a bad diet” are common in fitness circles and with lay people alike for exactly that reason – dietary changes are often required for weight management. Eating more protein is one lever that many people pull in an attempt to eat a more health promoting diet that encourages weight loss. But, how can eating more of something lead to weight loss? 

The common claim concerning weight loss is that high protein diets are more filling than others thereby causing you to eat fewer Calories in total. This claim is pervasive in the health and fitness space, but, is there any science to back it up? And just how much protein do we need to eat for health and weight management?

In this article we’re going to explore whether or not protein is actually more filling than other foods and whether or not increasing our protein intake results in better outcomes with respect to weight loss.

Note: Want to hear more out more about this topic? Listen to Podcast #286 by clicking here.

How Much Protein Do We Need For Weight Loss?

Along with carbohydrates and fats, protein is one of the three calorie-containing nutrients termed macronutrients – or macros. Dietary protein provides the essential amino acids we need for many biological processes including building muscle, synthesizing enzymes, proper brain function, and more. Over 40% of the body’s protein is found in the skeletal muscle, another 25% is in the body’s organs, and the rest is in the skin and blood. Bodily proteins like collagen in our connective tissue, actin and myosin in our skeletal muscle fibers, and keratin in our hair are unique in their characteristics due to the number, sequence, and pattern of these amino acids that comprise their structure. 

Recommended Protein Intake 

The recommended dietary allowance, or RDA, is the average intake sufficient to meet the nutrient requirements of nearly all healthy people. Here’s another way to think of the RDA – the minimum intake to avoid protein deficiency in most people. For adults, the RDA for protein is 0.8 grams per kilogram of bodyweight per day. For an 80 kilogram (176 pound) person, this translates to 64 grams of protein per day. For the average person, this equates to roughly 10-15% of total daily caloric intake.

If that seems like a low recommendation to you, there are many who agree. The International Society of Sports Nutrition (ISSN) have recommendations for adults engaging in physical exercise that are significantly higher. The ISSN recommendation for adults engaging in exercise is 1.4-2.0 grams per kilogram of bodyweight per day.¹ For the same 80 kilogram (176 pound) person above, the recommended protein intake jumps up from 64 grams to between 104 to 160 grams of protein per day. 

Our protein guidelines are similar, as we recommend 1.4-2.2 grams of protein per kilogram of bodyweight per day for adults who are exercising. Hard-training, very lean athletes may benefit from even higher doses, but this is a more individualized consideration. 

In any case, these recommendations are quite different from one organization to another. But that’s all these numbers are: recommendations. How much protein are people actually eating?

Most adults eat far more protein than the current RDA. In the US the typical adult averages 88 grams of protein per day, or 1.07 g/kg of body weight per day.^2,3 About half of this protein is from animals, with whole chicken, cold cuts, and mixed meat dishes being the top three sources.⁴

It’s important to know these reference numbers and recommendations because when we discuss “increasing protein intake” we have to know where people are starting from. If someone is eating below the current RDA, then doubling their protein intake will likely have a much larger impact as compared to someone who increased their protein intake from 1.8 g/kg of bodyweight to 1.9 g/kg of bodyweight. Going one step further, when we say “increase protein intake” we have to know what we are increasing it to. Increasing protein intake from 0.8 g/kg to 2.0 g/kg will likely have a larger effect than increasing from 0.8 g/kg to 0.9 g/kg.

Is There Such A Thing As Too Much Protein?

More than doubling the RDA? Isn’t that too much protein? Concerns that high protein diets (HPDs) may cause damage to the kidneys, bones, or liver, or increase the risk of kidney stones, are generally not supported by evidence in healthy individuals. While HPDs were once primarily seen as beneficial only for athletes, the apparent popularity of higher protein diets has increased over the past 20 years, with many Americans agreeing that HPDs can help with weight loss. 

In reality, most American adults already consume a relatively high amount of protein, typically 1.0–1.5 g/kg/d (14–16% of total energy), which is already above the current RDA. Eating patterns promoted in the 2020 Dietary Guidelines for Americans, such as the Healthy Vegetarian and Healthy U.S.-Style, equate to protein intakes 1.55- to 1.98-fold greater than the current RDA.

The premise that high protein intake increases the risk of kidney disease by forcing the kidney to deal with breakdown products like urea, leading to hyperfiltration and damage, is not supported by real evidence in those with normal kidney function. Hyperfiltration—an increase in the glomerular filtration rate (GFR)—is a normal, adaptive function of the kidney to increase solute clearance in response to a higher nitrogen load, which doesn’t represent a risk factor for developing Chronic Kidney Disease (CKD). Multiple systematic reviews and meta-analyses show that high protein consumption (averaging around 1.8 g/kg/d) has a trivial or nonexistent effect on GFR in individuals with normal kidney function and may even be protective against kidney disease.⁴⁵ Similarly, the concern that HPDs increase urinary calcium loss, leading to bone loss (osteoporosis) or kidney stones, is not borne out by long-term data.

Dietary protein levels above the current RDA, provided calcium intakes are adequate, may actually be beneficial in reducing bone loss and hip fracture risk, especially in older people with osteoporosis.⁴⁶ Insufficient dietary protein may be a more severe problem than excess protein in the elderly. Regarding kidney stones, total protein intake is generally not associated with increased risk. The risk for kidney stones is more closely associated with the overall dietary pattern, with high-potassium foods like fruits and vegetables, and increased fluid intake potentially reducing risk.^{47, 48}  Finally, while protein metabolism produces ammonia, which is eventually converted to urea for excretion, the short-term increase in blood ammonia from an HPD is unlikely to rise to harmful levels in a healthy person with normal liver function.⁴⁹ Overall, increased dietary protein intake above the RDA appears to be safe, well-tolerated, and likely beneficial for strength and muscle gains.

Note: Want to hear more out more about this topic? Listen to Podcast #248 by clicking here.

Now that we have a better idea about how much protein we need and dispelled some HPD myths, let’s address one of the big reasons people are recommending increasing protein intake for weight management: protein is more filling so you consume fewer Calories overall and lose weight.

Appetite, Satiety, and Weight Regulation 

Before we can answer the question of whether or not protein is in fact more satiating, we should come to an understanding of what satiety is. And in order to understand satiety, we must also understand appetite. Appetite and satiety can be considered opposing forces influencing our food-related behaviors.

Appetite is the subconscious integration of biological, psychological, social, and environmental factors resulting in the conscious experience of hunger. Appetite is driven by very powerful, subconscious processes in an effort to ensure that energy intake meets energy requirements as well as desires for certain types of foods. In the presence of these signals we seek out both Calories and certain types of foods. 

On the flip side, we have satiety. Satiety is the feeling or state that inhibits further eating. Satiation occurs at the time of eating and refers to the processes leading to the termination of a meal. This is due to the cumulative effect of hormonal, digestive, cognitive, and sensory appetite-inhibiting signals. It’s best to think of this as a cascade of signals that inhibit appetite. In the presence of these myriad signals, we stop eating. 

The signals for both appetite and satiety are primarily subconscious, so this is beyond our choice. Whether hunger or satiety predominate, a corresponding food-behavior follows – either we eat or we stop eating.

From our experience eating a variety of different foods we know that some foods provide a larger satiating effect than others. The failure of a food or meal to provide satiety despite providing adequate Calories is an important mechanism of obesity. For example, sugar sweetened beverages like soda provide between 100-200 Calories per serving but do not provide much in terms of satiety. 

In a perfect world, the presence of excess energy stores, like body fat, would produce early satiation during a meal and long-lasting satiety between meals, ultimately leading to a normalization of body weight and body fat. Essentially, the body would detect that we have ample Calories stored in our adipose so it would send us signals to eat less food. Unfortunately, this doesn’t seem to be the case in most people with overweight and obesity.  Two factors likely determine this mismatch in signalling: the individual’s genetics and the food environment that makes high Calorie foods that aren’t very satiating easily available and desirable. 

One of the reasons that increased protein intake is often recommended is that a high protein content food or meal is usually more satiating. The idea here is that a more satiating meal would cause people to eat less food thus promoting weight management or weight loss. Here-in lies the real question we have. Does eating more protein result in fewer calories consumed and better weight management? 

There are three potential mechanisms that have been explored in the research to answer the question: is protein uniquely more satiating than other foods? These studies focus on how protein affects levels of gut-derived satiety hormones, increased levels of circulating amino acids in the blood, and levels of gluconeogenesis. 

The Science Behind Protein and Weight Loss

As mentioned above, increased protein intake is said to increase feelings of fullness or satiety via several mechanisms. They are:

1. Increased levels of gut-derived satiety hormones 
2. Increased levels of circulating amino acids in the blood
3. Higher levels of gluconeogenesis 

This section is going to get into the weeds a bit with regard to human physiology and biochemistry; if you just care more about outcomes, scroll down a bit to the next section! Otherwise, stay, read, nerd out with us. 

Increased Satiety and Reduced Cravings: Hormonal Factors

There are short and long-term hormonal signals influencing hunger, satiety, and subsequent energy intake. In Greek, orexin means appetite, so hormones that increase satiety and reduce appetite are called anorexigenic hormones, where those that increase appetite and decrease satiety are orexigenic. 

Short-term hormones include:

• Cholecystokinin (CCK): a hormone made in cells of the small intestine and intestinal nerves. It stimulates gallbladder contraction, inhibits emptying of the stomach, and promotes satiety.
• Peptide-YY (PYY): a hormone made by cells in the small intestine. It inhibits the release of pancreatic enzymes and acid in the stomach as well as intestinal motility. It promotes satiety.
• Glucagon-Like Peptide I (GLP-1): a hormone made by cells in the small and large intestine and function to stimulate cell growth in the GI tract, inhibit intestinal motility, and influence insulin and glucagon release. It promotes satiety, but circulates at relatively low levels. 

If GLP-1 sounds familiar, it’s because this hormone is targeted by GLP-1 receptor agonists like semaglutide. This means the medication binds to the GLP-1 receptors, which are mostly in the brain in areas dealing with appetite, satiety, and food-related behaviors. Levels of GLP-1 obtained through medication are also much higher than those made by the brain or gut. Interestingly, mice who don’t make any gut-derived GLP-1 do not have increased food intake or bodyweight, thus it is thought that gut-derived GLP-1 is not essential for controlling food intake or weight. Rather, GLP-1 made by the brain seems to be more important for food-related intake.⁶

To summarize, CCK and PYY are short-term or episodic satiety hormones. The available evidence suggests higher dietary protein content in a meal increases these hormones. To the extent that gut-derived GLP-1 is a satiety promoting hormone, protein intake also tends to increase that too.^{7, 8, 9}

So here we have one signal indicating that higher protein intakes is associated with increased satiety via levels of these hormones – at least in the short term. If the question is simply “does increasing protein intake increase satiety-related hormones” then the answer is clearly yes. 

While this is promising, we’re really interested in the outcomes associated with increases in dietary protein such as helping people eat fewer Calories and lose more weight and body fat. For that answer, we’ll have to keep digging.

Two hormones not mentioned in this discussion are ghrelin and leptin. These two hormones are often discussed around satiety and appetite but their role in obesity, weight management, and satiety is misunderstood. 

Leptin is a hormone made by body fat, or adipose tissue, in proportion to the amount of body fat an individual carries. The more body fat someone has, the higher the leptin level they’ll have. It was once thought that leptin was another satiety hormone acting in the medium to long-term. The thought was that high body fat levels would signal to the brain that there was too much body fat being stored and therefore increase feelings of fullness as a result to reduce Caloric intake. As mentioned in the earlier discussion of satiety and appetite, we see this isn’t necessarily the case in people with overweight and obesity. High levels of leptin do not reduce hunger or Calorie intake in individuals with obesity. This finding has been described as leptin resistance, where the body’s response to increasing levels of leptin is less than predicted. 

Multiple different takes on this theory have been promoted over the past 25 years. Issues with the leptin transporter, obesity-induced changes to neural cells responding to leptin, and others have been suggested. The specific mechanisms for leptin resistance remain unknown.¹⁰ Even when researchers gave people exogenous leptin, there was little to no effect on appetite, energy intake, or body weight.¹¹ To date, studies consistently find little association with elevated or increasing leptin levels and reduced appetite.

Instead, low levels of leptin reflect reduced body fat stores and strongly promote food-seeking behavior, reduced physical activity, and increased hunger signaling in conjunction with other hormones. This has been shown during periods of starvation and in individuals with anorexia nervosa.¹²  Overall, the data suggests that leptin’s strongest functions occur when levels are low, rather than when they are high which have implications for weight gain, but not weight loss. 

Ghrelin is another hormone of interest with regards to protein intake. Ghrelin is a hormone made by cells in the small intestine and stomach. Ghrelin levels rise during fasting and decrease immediately after eating. It acts primarily on an area of the brain called the hypothalamus to promote hunger and food intake, though it also increases how fast the stomach empties as another mechanism of increased appetite.  Ghrelin levels tend to increase during periods of fasting between meals and decrease after eating.¹³ In general, most studies show that protein intake reduces ghrelin as a mechanism to reduce appetite. So, while not directly increasing satiety, protein reduces ghrelin thus reducing appetite. 

Let’s look at another proposed mechanism for protein to increase satiety. 

Increases in Amino Acids in the Blood: The Aminostatic Theory

All dietary protein gets broken down into short peptides and single amino acids during digestion. These amino acids are the building blocks that combine by the hundreds and thousands to make up actual proteins like collagen, elastin, actin, and myosin. Once in the small intestine, these individual amino acids and short peptides are absorbed into the bloodstream of the portal vein, which then takes them to the liver for further processing and utilization.

There are some that believe that eating higher protein meals would produce higher levels of amino acids in the blood, which then would increase feelings of fullness.

For example, it was thought that a greater concentration of the amino acid tryptophan in the bloodstream might increase levels of the neurotransmitters serotonin and dopamine, thereby affecting appetite and satiety at the level of the brain. However, there’s no real evidence that eating a higher protein diet does this compared to eating a Calorie-matched meal with lower levels of protein.

Another theory, called the aminostatic theory, predicts that a rise in amino acids within the bloodstream in general will decrease appetite.¹⁴ However, this theory is not well supported because fasting blood levels of amino acids are not associated with appetite and an increase in amino acids within the bloodstream isn’t consistently associated with satiety either.¹⁵ This mechanism does not appear to contribute to any feelings of fullness or reduced Calorie intake from dietary protein. 

The last mechanism has to do with a process known as gluconeogenesis.

Blood Sugar Control and Insulin Sensitivity

Gluconeogenesis is the creation of new glucose, or sugar, from different precursors. Amino acids are one of these non-carbohydrate precursors that can be used to create new glucose. There are two claims as to why this may make increased protein levels helpful for fat loss – increased satiety and increased energy expenditure. Some claim that eating a high protein diet increases the rate of gluconeogenesis, and because this process is very inefficient, it costs the body a lot of energy thereby increasing energy expenditure. It’s also claimed that the increased production in glucose may help maintain blood sugar levels, thereby contributing to satiety.¹⁶

While there’s some data showing higher rates of gluconeogenesis with a higher protein diet, there’s not really a consistent relationship between the increase in gluconeogenesis and appetite ratings.¹⁷ 

So, while there is some scientific basis for these claims, they haven’t shown to actually produce the outcomes we are concerned about: decreased energy intake leading to better weight management.

At this point, only one of these three mechanisms show any promise with regard to protein and satiety. While certain short term hormones associated with satiety increase after protein is eaten, we need to investigate whether or not this actually promotes the outcome we truly care about – weight loss and weight management.

Examining these mechanisms can help to inform decisions, but perhaps it would be better to stop looking for how a higher protein diet works for controlling appetite, and start looking at if a high protein diet actually helps with weight loss. 

Does Increasing Protein Intake Help With Weight Loss? 

Let’s revisit the intro to this entire article and the reason why many are attempting to eat more protein. This dietary approach is often taken by those seeking to improve their body composition or to lose fat. Unless you’re a gut-hormone researcher or physiology nerd, we don’t really care how filling protein is in a single meal. What we really want to know is if adopting a high protein dietary pattern reduces Caloric intake over days, weeks, and months, subsequently producing greater weight and fat loss, preventing weight regain, and so on. 

In this regard, it is of more clinical utility to focus on the data regarding that specific outcome: Calories consumed and changes to body weight in response to higher protein intakes. 

A classic study from the 90’s had subjects rate their satiety after eating 38 different foods. Researchers crunched the data to produce a satiety index, where higher levels of protein, fiber, and water content in the food correlated with higher satiety ratings, and foods with higher levels of sodium, fat, or added sugar were less satiating.¹⁸

This information helps with selecting more satiating foods. When it comes to increasing protein intake we have to know where people are starting from and how high we are increasing protein to. One of the issues with research in this field is that there is no agreed upon definition of what a high protein diet actually is. 

Some have suggested that anything higher than the RDA of 0.8g/kg of body weight per day should be considered high, though this would mean that most Americans are eating a high protein diet already. Others have suggested that a diet where > 25% of daily Calories come from protein is high, and if it’s greater than 35%, it’s extremely high. There’s no agreed upon cutoff here, which can make the data a bit confusing to interpret. Let’s keep that in mind when evaluating the results of these studies. 

Does a Higher Protein Intake Increase Weight Loss Without Calorie Restriction? 

Ad libitum diets are those where the Calories are not explicitly restricted. Instead, folks are instructed to eat as much as they would like from a given set of foods.  

In one 1999 study,¹⁹ 65 adults with overweight or obesity ate one of 3 diets over a 6-month period:

1. A high protein diet – 25% of daily Calories were from protein
2. A high carb diet – only 12% of daily Calories were from protein
3. A control diet in which people were instructed to keep eating their normal diet

Subjects were instructed to eat to their desired fullness. In other words, they were not instructed to reduce intake. Over the 6 month period, the high protein group lost 8.9kg in total weight and 7.6kg of fat, whereas the high carb group lost 5.1kg of total weight and 4.3kg of fat after 6 months. 35% of the participants in the high protein group lost 10kg or more, whereas only 9% in the high carb group lost more than 10kg.

This seems like a win for Big Protein – but bear in mind both groups lost fat. This is just one study, does the rest of the body of evidence agree?

A 2020 systematic review & meta-analysis²⁰ – a study of studies – compared the effects of an ad libitum high or normal protein diet on weight management and body composition. The research group pooled the data of 10 studies including over 1,000 adults to find smaller, but similar results to the 1999 study mentioned above.

Both groups lost weight and there wasn’t a big difference between those who ate on the higher end vs. the lower end of protein intake.  However, the higher protein group did tend to preserve more lean body mass while losing weight – more on this below. As far as the satiating effect of protein, the authors found that a more pronounced effect was noted during shorter duration studies and the effect seems to become minimized as time goes on.

It seems that while increased protein intake can aid in weight loss, it does not do so if care is not taken to reduce total Caloric intake. The important thing about these particular studies is that the participants were not placed in a Caloric deficit. It is well understood that a Caloric deficit is required for weight loss. Let’s see how that plays out with higher protein intake.

Higher Protein Diets Improve Weight Loss and Muscle Retention With Calorie Restriction

We do see differences between higher protein intakes and outcomes regarding weight management and fat loss when people are in a Caloric deficit. In addition to this, higher protein diets may also aid in preserving lean body mass – think muscle – when losing weight on a diet. 

A 2012 systematic review & meta-analysis²¹ of 24 randomized controlled trials compared energy restricted high protein diets with energy restricted standard protein diets. These 24 trials involved around 1,000 participants and averaged about 12 weeks in length. They compared these diets in terms of weight management, body composition, and various health parameters. This study found that:

• The high protein diets averaged between 1.1 and 1.6 g/kg/day (about 30% total daily energy intake)
• The standard protein diets averaged around 0.6 to 0.8 g/kg/day (about 20% total daily energy intake)
• The energy difference between the two diets was about 300 Calories, with the high protein diet groups eating 300 Calories less on average than the standard protein group
• The high protein diet groups lost an average of 0.8kg more of total body weight than the standard protein group
• The extra 0.8kg lost was mostly fat mass
• The high protein groups retained an average of 0.5kg more lean body mass than the standard protein group
• Triglycerides were about 20 mg/dL lower in the high protein group
• The resting energy expenditure was also about 300 Calories/day higher in the high protein group, which could be due to the retention of muscle 

In short, the high protein group ate almost double the protein while consuming around 300 fewer Calories per day resulting in more fat loss, better muscle retention, and overall health improvement. This study seems to point us in the right direction with our big question: do higher protein intakes result in fewer Calories consumed and weight loss – yes.

Another 2012 systematic review & meta-analysis²² of 74 randomized controlled trials compared energy restricted high and standard protein diet saw similar results but the differences in outcomes were smaller:

• The high protein groups lost just under a pound more than the standard protein groups
• There were additional smaller benefits like a reduction in waist circumference and reduced resting blood pressure, but these benefits were so small in size that they may not be clinically significant

Another win for Big Protein. It seems that eating a higher protein diet may have small, but significant effects on how much weight you lose while in a Caloric deficit and may help you retain more muscle during your weight loss efforts. 

Another important note, it does appear that eating more protein could aid in preventing weight regain after a period of weight loss. 

In a weight regain study of 113 adults with overweight who previously lost 5 to 10% of their initial body weight, the group consuming a higher protein diet – about 1 scoop of whey protein more per day – regained 0.8kg over 6 months, whereas those not getting the protein shake regained an average of 3kg.²³

To summarize the previous 2 sections, it seems that higher protein intakes are associated with small but significant reductions in total Calories consumed, more fat loss during a weight loss diet, and more muscle retention during a fat loss diet. The advice to eat more protein when trying to lose weight seems to hold up here! 

Top Sources of Protein For Weight Loss

We can consume dietary protein from a wide variety of sources to meet our daily protein needs. It is worth noting, however, that not all protein sources are equal in their amino acid profile, saturated fat content, carbohydrate content, and total calorie content. In that regard, it becomes important where you get your protein from as it can have implications for your overall health and achieving fitness or weight loss goals. Let’s dive into a few sources of dietary protein to maximize your health and weight loss results.

Lean Animal Proteins 

All proteins from animal sources such as poultry, beef, or pork are called complete proteins. This means that they contain all of the essential amino acids that must be consumed in the diet in appropriate quantities making them a good choice for muscle building and dieting for weight loss. That being said, animal proteins can also be sources of saturated fats. 

Most sound advice on health promoting dietary practices promotes a reduction in saturated fat intake. Specifics surrounding the biochemistry of saturated fats and their effects on human physiology and health are beyond the scope of this article. To reduce saturated fat intake, we recommend focusing on leaner cuts of animal proteins. 

Lean cuts of meat would include chicken or turkey breast over thighs or wings, pork tenderloin over pork chops or bacon, and a sirloin or filet over a ribeye steak. Focusing on leaner cuts of meat will not only reduce saturated fat content but will also reduce the total Calories from that particular food source. By choosing leaner animal proteins, you are ensuring that the majority of the Calories coming from your protein source are indeed from protein. 

Dairy and Eggs 

Dairy and eggs represent two more animal based protein options that are considered complete proteins. Dairy and eggs can be an excellent source of protein for “lacto-ovo” vegetarians and meat-eaters alike. 

While these are complete proteins, we still recommend being mindful of total Calorie and saturated fat intake of these foods. For example, non-fat Greek yogurt and sharp cheddar cheese are both dairy products that contain protein but their macronutrient profile, protein content, and Calorie content are very different. These foods can absolutely be part of an overall health promoting diet and are great sources of complete protein – we just recommend opting for the lower fat options to keep total Caloric intake in balance and saturated fat on the lower end of the recommended range. 

Plant-Based Proteins

Plant-based foods are another protein source that can help people reach their daily protein intake goals. The one note regarding plant-based proteins is that not all of them are complete proteins. Some plant-based proteins are incomplete – meaning they lack at least 1 essential amino acid in sufficient quantities. 

This isn’t the case for all plant-based proteins, however. For example, tofu, quinoa, and chia seeds contain all the essential amino acids in adequate quantities. 

Incomplete sources of plant protein include nuts, seeds, and most legumes. If the majority of your diet comes from these incomplete sources, we recommend varying what types of foods you’re eating to ensure you are getting all of the essential amino acids. 

Plant-based sources of protein may also come packed with other nutrients. Legumes for example are great sources of carbohydrates and fiber. Nuts and seeds are great sources of monounsaturated and polyunsaturated fats. This also means that these foods contain Calories from other macronutrients – fats and carbohydrates, not just protein. So, just like with the animal based proteins care should be taken to monitor total Caloric intake of these foods if weight management is a concern. 

Protein source, whether plant or animal-based, does not appear to influence strength, hypertrophy, or other training outcomes provided the correct amount of protein is being consumed.

Protein Supplements: When and Why to Use Them 

It is entirely possible to meet your daily protein needs without the use of supplements. That being said, a protein supplement can be useful for some to quickly add 20-30 grams of high quality, complete protein to your diet. 

Protein supplements are typically made of a dairy derivative, like whey or casein protein, but also come from vegetarian sources like soy, rice, pea, or a blend of several plant-based sources. All can work equally well if taken at the doses recommended in this article. 

For those choosing to use a protein supplement, we recommend selecting one that is produced by a manufacturer that follows FDA regulations around current Good Manufacturing Practices (cGMP) and is 3rd party tested to avoid unwanted contamination. Other markers of a good protein supplement include being under ~120 Calories, having ~20g of protein per serving, and no evidence of protein spiking with added glutamine, creatine, taurine, or glycine.

For those interested in a high quality whey protein isolate, our WheyRx Protein has between 20-21 grams of protein and only 90 calories. We have complete transparency of our ingredients and don’t include proprietary blends so you know exactly what is in our product. We are also 3rd party certified and Good Manufacturing Practices (cGMP) accredited.

Addressing Common Protein and Weight Loss Questions

Will Eating More Protein Make Me Bulky?

A common misconception of higher protein diets  is that they make people look “bulkier.” High protein diets and protein supplementation are popular and very common in bodybuilding and powerlifting circles alike, so many people associate these types of diets with the look of a large bodybuilder. This outcome is unlikely to occur simply from eating more protein, but there is an important note that this question brings up. 

Weight management always comes back to Calorie balance. A surplus of Calories generally leads to weight gain and a deficit of Calories generally leads to weight loss. Foods that contain protein also contain calories. If you are adding in more protein but removing nothing else, you are definitely at risk for increasing your total Caloric intake. It may be important to be mindful of removing Calories from other food sources to make sure you aren’t in a Caloric surplus. 

To avoid “bulking up” from increasing your protein intake take care to remove some fats and/or carbohydrates from your diet in order to maintain Calorie balance. 

How Does Protein Fit into Different Diet Plans (Keto, Vegetarian, Vegan)?

Protein should be a part of every health promoting dietary pattern. What changes from diet to diet, however, is the amount of protein consumed and possibly what types of foods the protein is coming from.

A ketogenic diet typically consists of very high relative amounts of fat in the diet followed by moderate protein intake and very low relative amounts of carbohydrates. Most dietary proteins with minimal carbohydrates would fit into this dietary pattern. 

Vegetarian and vegan diets also should contain adequate protein intake to support health and physical activity goals. Vegetarians typically still consume eggs and dairy, so they have much more versatility when it comes to protein intake. Vegans, however, who do not consume any animal products may have more difficulty eating enough protein. In this case, it may be beneficial to consider a vegan protein supplement. All of that said, vegetarians and vegans can certainly meet their protein needs with non-animal sources, it may just take some extra care. 

Regardless of the dietary pattern chosen, we still recommend the same total protein intake per day to optimize results from exercise and to support a healthy body weight. These recommendations are summarized at the end of the article. 

What About Digestive Issues from High Protein Intake?

Some folks report having issues with digestion or symptoms related to a GI disturbance from high protein diets –bloating, pain, nausea, diarrhea, etc. This is a very individualized experience whereas some people can consume very high levels of protein without any issue and others can have issues with more moderate levels. It may be appropriate to consult with a qualified healthcare provider – such as a registered dietitian – about these digestive issues. This will ensure you not only achieve adequate nutritional intake but also eat the right foods for your body. 

If you experience gastrointestinal distress from high protein intake, consider a consultation with a registered dietitian from Barbell Medicine. 

Conclusion: The Power Of Protein (Kinda)

Increased protein intake seems to be a useful lever to pull when trying to adjust the dietary pattern to one that promotes weight loss and muscle maintenance.

We’ve gone through a lot of science and information to get here, which can be summarized in three main points:

1. Eating more protein may result in people spontaneously eating fewer Calories, thereby supporting improved weight loss and overall weight management 
2. Eating just a little more protein likely increases the amount of weight and body fat people lose when they’re trying to eat in an Caloric deficit
3. Eating a higher protein diet definitely seems to support muscle mass growth and maintenance better than a lower protein diet

These points aren’t controversial or making headlines, but good nutritional advice seldom does. They also don’t really answer the question of whether or not protein is uniquely satiating in the long-term, thereby leading to better weight management. If the question was simply, does a protein intake higher than the RDA lead to better weight management, then the answer is clearly yes. However, the question of protein causing higher levels of satiety long-term, thereby producing better weight management is more complex.

Hundreds of studies confirm a modest satiety effect with high protein meals when using the visual analogue scale right after eating. However, when these studies also measure energy intake at the next meal, there’s not a reliable effect of increasing protein. Research is needed to examine whether the satiety effects of protein promote voluntary reductions in energy intake and improved body weight management over the long term.

Given the limitations of the research,  we cannot yet confidently say that more protein = more satiety. While various gut-derived satiety hormones increase with more protein at a meal this doesn’t reliably correlate with someone consuming fewer Calories in the next meal or in the whole day. 

A potential mechanism that explains the phenomenon of eating fewer Calories with a higher protein diet is simpler – higher protein intakes may be displacing highly palatable, highly rewarding foods with lower Calorie options. By adopting a higher protein diet, people may be invariably choosing a healthier dietary pattern overall that limits the foods that people tend to overeat. 

There’s some evidence that higher protein meals tend to be less tasty or palatable than lower protein meals. These meals may not trip any of the sensory-mediated food reward mechanisms we see with regular consumption of ultra-processed foods with added sodium, added sugar, and/or added fat. 

As discussed in the beginning, most people are consuming more protein than advised per the RDA. However, the general quality of the diet is low based on relatively low levels of fiber-containing foods like fruits, vegetables, legumes, and whole grains, and inclusion of many ultra-processed foods containing added sugars, added sodium, and added fat. Getting these individuals to increase their dietary protein intake by including lean protein sources can lead to multiple additional changes in the dietary pattern, such as shifting towards lower Calorie sources of protein and reducing the intake of ultra-processed foods.

Combining these mechanisms together with better support of muscle mass, and the addition of protein to the diet helps improve weight management. 

As far as take-home recommendations go, a reasonable recommendation would be to adopt a protein intake similar to the aforementioned ISSN level and inline with our protein guidelines. This would mean a near-doubling of the RDA’s protein intake level, aiming for somewhere in the 1.4 to 1.6 grams of protein per kilogram bodyweight level. Within that, each meal should have about 25 to 40 grams of total protein minimum, to not only reach the threshold for muscle protein synthesis, but also to provide a decent short term satiety signal, however the minimum threshold of protein per meal to trigger satiety is unknown. 

A focus on creating a food environment that facilitates getting an extra 30 to 50 grams of protein per day in the dietary pattern and supporting behaviors is good practice. The potential mechanisms by which this works are interesting, but don’t provide a very strong mechanism for which this works beyond supporting lean muscle mass. 

There isn’t good evidence that increasing intakes above this recommended level of 1.4-1.6 grams of protein per kilogram of bodyweight works better beyond satisfying someone’s personal preference. However, there is a chance that eating very high protein levels above this mark may displace other foods like fruits, vegetables, legumes, or whole grains.^42,9,43,44

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There are several training variables we can adjust to get the most out of our program. We may carefully manipulate the load we’re lifting, the intensity of each set, and our total weekly volume in order to get closer to a particular outcome like increasing muscle size or getting stronger on a particular lift. For many lifters, rest times between sets is often an afterthought, yet choosing to rest too little or too long could mean leaving potential strength and muscle gains on the table. 

This article takes a science based approach to rest periods in order to potentially maximize performance in a given exercise session, which repeated over time, could yield better improvements in strength and muscle gain.

Note: For more information and nuance on this topic, check out episode #275 on the Barbell Medicine Podcast by clicking here.

Why Do We Need to Rest Between Sets?

Before we discuss how much to rest, we need to know why we have to. The purpose of a rest period is to dissipate fatigue that accumulates during the set that was just performed. Any set of an exercise produces some amount of fatigue. Some sets are capable of producing more fatigue, or different types of fatigue, than others. For example, performing a set of 12 reps of biceps curls to an RPE of 7 may produce a different amount and type of fatigue than a set of 3 deadlifts at an RPE of 9. Further, you may need to rest shorter or longer after each of those efforts before doing another set of biceps curls or deadlifts.

The Relationship Between Rest, Intensity, Volume, and Fatigue

Fatigue represents the subjective experience of a number of exercise-induced changes in an individual such as muscular soreness, muscular damage, tiredness, etc. that can lead to reduced force production. There is also likely to be some controversy in this definition of fatigue, as others define muscle fatigue as purely a decrease in force production potential, which can be measured by a strength test. To use the same exercise examples as above, your force production potential immediately after completing a triple on the deadlift at an RPE of 9 or a set of 12 on biceps curls at an RPE of 7 will be less than it was before you did the set. 

Neurologically, the production of muscular force has both central and peripheral components. Because of this, as does fatigue. In this view, muscle fatigue represents the performance difference between before and after the intervention – a hard set – and is divided into central and peripheral components. 

Peripheral fatigue is produced by changes at or downstream to the neuromuscular junction – where the nerve meets the muscle. The signal that gets the muscle to contract is still preserved, but the contraction produces less force. Peripheral fatigue can be caused by things like muscle damage, the accumulation of metabolic byproducts like lactate and hydrogen ions that occurs with repeated muscle contraction, and and the depletion of energy substrates like ATP (adenosine triphosphate) and PCr (phosphocreatine).

On the other end, central fatigue stems from changes upstream to the neuromuscular junction – the brain, the spinal cord, and the nerves supplying the muscles. This type of fatigue results in a smaller than normal signal being sent to the muscle, thereby causing the muscle to produce less force. A number of neurotransmitters like serotonin, dopamine, and norepinephrine are involved. This is one of the potential mechanisms by which methylphenidate – the active drug in ritalin or concerta – is thought to increase physical performance. Other mechanisms include some of the metabolic byproducts discussed above as well as mechanical tension itself stimulating group III and IV afferent nerves that can inhibit muscle contraction signaling.²

Both central and peripheral factors can contribute to the experience of fatigue. As far as the body of literature that is currently available, it seems to focus mostly on energy availability and the removal of metabolic byproducts as factors causing peripheral fatigue. There is limited data at this time on the factors affecting central fatigue. So, let’s focus on the peripheral components to attempt to answer the question of why we rest. 

What Happens During Rest Intervals? (Energy system recovery, ATP, and PCr)

From an energy standpoint in strength and hypertrophy training, the two biggest players here are thought to be ATP and PCr. 

The molecule ATP stores energy in its phosphate bonds. The “tri” in adenosine triphosphate means that this molecule has 3 phosphate groups. When we use an ATP molecule for energy, we clip one of these phosphates off and the breaking of that bond releases usable energy. This breakdown of ATP leaves behind its constituent components adenosine diphosphate (ADP) and inorganic phosphate (Pi). Skeletal muscles then transform this released chemical energy into mechanical energy causing a muscle contraction. 

ATP is a relatively heavy molecule, so we do not store a lot of it in our muscles. Instead, we store other molecules and have several bioenergetic pathways to replenish ATP just as rapidly as we use it up. Because we are pretty good at replenishing ATP, the decrease in ATP levels during resistance training is usually small or statistically insignificant. Multiple studies have shown this, suggesting that ATP is being almost entirely regenerated during exercise and we probably don’t need to rest a lot in order to replenish our ATP stores. Because of the relatively quick regeneration, our limited ATP stores are back to 100% after about 3 to 5 minutes of rest following strenuous exercise.

So, we aren’t necessarily resting to restore ATP as that seems to happen almost instantly. PCr, another molecule stored in the muscle in higher quantities than ATP, is used to regenerate ATP very rapidly. PCr helps turn that molecule ADP back to usable ATP. PCr levels in the muscle plummet during a hard set or anaerobic effort, with some studies showing up to an 80% drop in PCr levels during a single, short effort of less than 45 seconds. These same studies show it takes about 8 minutes to fully replenish PCr levels back to pre-exercise conditions.³ 

This interaction between ATP and PCr is not the only supplier of energy during hard sets or anaerobic efforts. The other contributor to muscle energy during lifting is the breakdown of muscle glycogen, the stored form of carbohydrates in our muscles. This process is called glycogenolysis and the energy system acting here is termed anaerobic glycolysis. While ATP and PCr are doing their thing, muscle glycogen breakdown is also contributing to ATP regeneration to fuel muscle contraction. This process of anaerobic glycolysis does two things that contribute to peripheral fatigue. First, it creates lactate and hydrogen ions as a byproduct which makes the muscle a little more acidic thus impairing calcium release within the muscle and impairing contraction. Second, it’s depleting the stored carbohydrates we have in our muscles – muscle glycogen.  

While these factors from the breakdown of glycogen can play a role in peripheral fatigue, it usually isn’t as large of a factor for short term sets. This process seems to peak at about 45 seconds of output. So, doing 400m repeats on a track would certainly generate fatigue from this mechanism. For sets that take a long time – high reps, drop sets, extended tempo work, and so on – this is probably a factor. But what about fatigue from short sets? A set of 3 reps on the squat at an RPE of 8 would not likely generate a large amount of fatigue from these bioenergetic mechanisms. 

Current evidence suggests that the combined decrease in phosphocreatine (PCr) levels along with an increase in acidity from hydrogen ions following anaerobic glycolysis are two major mechanisms of action contributing to peripheral fatigue. As the set goes on, PCr depletion, glycogen depletion, increasing acidity, activation of group III and IV nerves, and so on likely all contribute to the experience of fatigue. 

While this review of exercise physiology was fun, there are a lot of factors involved in the experience of fatigue, and it’s hard to associate specific factors with a particular type of fatigue, central or peripheral.⁴  

What we do know about fatigue is that it happens as the demands of a task become greater and greater. So, using more weight, doing more sets, using more muscle mass, and getting closer to failure all increase this experience of fatigue. Anyone who has ever done a near maximal effort set or maximal effort sprint has experienced this. The more work done generates more fatigue. 

While this discussion of fatigue is important, this is an article about rest periods. And, the point of the rest period is to manage the accumulation of fatigue in a training session.

The point of a rest period is to allow the trainee to train with enough intensity to achieve their desired adaptation from training. 

This is going to be an important theme throughout the rest of the article. If rest periods are shortened too much, results suffer because people aren’t able to generate enough force or accumulate enough mechanical tension. If rest periods are lengthened too much, results may also suffer because people aren’t able to do enough exercise due to time constraints. 

As you may have guessed, there may be subtle differences in the amounts of rest that are optimal for different goals; strength or hypertrophy, for example. 

Let’s dive a bit into the research on different rest period protocols and their effect on performance.

How Long Should Rest Periods Be For Strength Training?

What drives the gains in strength that come from training? A combination of evidence and practical training and coaching experience tell us that the accumulation of training volume at an appropriate intensity drives our strength gains. In order to train this way we need to be able to continuously produce high levels of force throughout our entire workout.

If a rest period is too short, the trainee’s performance may dwindle on subsequent sets thus limiting the volume accumulated and the intensity used. So, if you rest too short the weight on the bar, the reps and sets performed, and the RPE level may be lower as compared to what you could accomplish using a longer rest period. If a rest period is too long, the training session may take too long and people may even lose interest making very long rest periods impractical. Both of these situations may be less than ideal for driving the desired adaptations.

To maximize strength gains, we recommend a rest period of between 2-5 minutes. Let’s take a look at how this shakes out in the research. 

A recent meta-analysis compared the results of 27 studies that evaluated 416 adults, mostly men, with 1 year of training or more. They examined the effects of traditional sets, like doing 8 reps, resting a few minutes, then doing another set of 8 reps, and so on as compared to something called rest redistribution. Rest redistribution is when an individual takes rests between reps of a set and then cuts down their rest period between sets. This is sort of like a cluster set. For example, you may do 5 reps, rest for 15-20 seconds, and then do 3 more reps, and then rest a full 90 seconds before your next set of 8 total reps that may have a rest somewhere in that 8 rep period. 

So, what did this meta-analysis find? When using rest redistribution, the weights being lifted had higher velocities, less velocity loss during the set, generated less lactate, and were rated at lower RPE’s by the lifters. When the rest periods between sets were extended – so cluster sets as described above with the same amount of rest between sets as a traditional set – the RPE and velocity loss tended to be even less. 

This speaks to possibly better recovery between sets; as the performance seemed to be better on subsequent sets as indicated by less velocity loss and lower RPE’s. 

The first takeaway here is that more rest can allow people to lift the same volume with less fatigue. Additionally, with emerging data showing that greater loss in velocities during a set tend to produce worse outcomes compared to a modest loss, the thought would be to rest long enough between sets to maintain your exertion level to keep bar speed from dropping too much and RPE from climbing too high. 

The second takeaway is that adding more total rest time can increase the duration of the training session, perhaps affecting adherence and the amount of volume that can be done. We know that training volume is very important to training outcomes like strength, size, and cardiorespiratory fitness, so we can’t rest for too long either. Unfortunately, this meta-analysis didn’t compare strength or size outcomes between cluster sets, rest redistribution, and traditional sets, so we don’t know which one worked better for what we really care about — how much rest do we need to optimize training performance, training outcomes, and time spent training. For that, we’ll need to dig into some more data.⁵

As far as strength is concerned, a 2017 meta analysis looked at 23 studies that all lasted at least 4-weeks and tested strength before and after the training intervention in 491 subjects. The subjects were mostly young men and half of the studies were in trained individuals while the other half was in untrained folks.⁶

In the trained subject studies, the longer rest intervals tended to maximize improvements in strength. One of the included studies compared rest periods of 30s, 90s, and 180s in 33 trained men to see how it affected their 1RM squat. All groups lifted 4 times per week for 5 weeks, alternating sessions of squats, push presses, bench presses, and some accessory work with clean pulls, power snatches, and rows, each done for 5 sets of 10 at a 10RM. The 180s group increased their squat 1RM by 7% whereas the 30s group increased their 1RM squat by only 2%. Interestingly, the 90 second group increased their squat 6%, despite requiring half the rest time as the 180s group.⁷

Another study in 36 men compared rest periods of 1, 3 and 5 minutes to each of 3 groups during a 16 week training program where they alternated upper and lower body days over 4 training sessions per week. In one session, they’d go heavy in the 4 to 6 rep max range. In the other session, they’d go a bit lighter in the 8 to 10 rep max range. They tested the 1RM bench press and leg press in each group at the end of the 16 weeks. A very important finding here, they did not all do the same volume, as the reps completed were affected by the rest periods used.

For example, the 5 minute rest group did about  40% more volume than the 1 minute group and 15% more than the 3-minute group. Due to this volume difference, the results are somewhat predictable.

For the leg press, the 1 min rest group improved by 22%, whereas the 3 min group improved 34%, and the 5 minute group improved 42%. For the bench press, the 1 minute group improved by 7%, the 3 minute group by 13% and the 5 minute group by 11%. The bench press surprisingly did not show a significant difference in 1RM between the 3 and 5 minute groups, but the relationship between 1 minute of rest and the other groups are pretty clear.⁸ 

A few of the other studies reviewed in the meta analysis compared longer rest periods of 4 and 5 minutes to shorter ones of 2 minutes to see if there were any differences. In general, the studies looking at longer rest periods showed that the individuals were able to lift heavier weights during the sets and do more reps as well. The only negative, as mentioned earlier, is that the 5 minute rest period group couldn’t do as much volume in the time allotted for training. At the end of 6 months in this particular study, there were no significant differences in strength or hypertrophy between the group resting 5 minutes vs 2 minutes.⁹

Finally, two more recent studies looked at the volume and velocity loss with short versus long rest intervals. Compared with rest periods of less than 2 minutes, longer rest periods consistently resulted in greater training volumes on average.¹⁰ Similarly, compared to resting only 1 minute in between 3 heavy sets of 5 on the squat or bench press, resting 3 or 5 minutes resulted in greater bar speed and less velocity loss on sets 2 and 3. Interestingly, there were no significant differences in velocity or velocity loss between resting 3 and 5 minutes.¹¹

Taken together with the other data collected in the meta analysis, it seems pretty clear that rest periods longer than 2 to 3 minutes are better for strength development in trained individuals as it seems to allow for the accumulation of more volume-load (sets x reps x load). It’s less clear if extending rest periods from 3 to 5 minutes or longer actually improves strength long-term, as rest periods of this length may compromise the ability to do enough volume in a workout.  In untrained individuals, the rest interval doesn’t seem to matter much based on the available data. In both untrained and trained individuals, shorter rest periods tends to make the sets in a session get closer to muscular failure and raise the RPE and discomfort of the session, which should be considered in programming.

Overall, strength gain seems to be maximized with longer rest periods in the 3 to 5 minute range for compound exercises. As someone becomes more trained, they may not require as long of rest periods before they can do the next set, thereby allowing them to do more training in the same amount of time. Longer rest periods of 5 minutes or greater may increase performance in the short term, but they can also limit the amount of training people can do in a session, ultimately limiting long-term development. If you’re in the final stages of prepping for a meet or 1RM test, resting longer than 5 minutes may be beneficial. Since volume should be rather low at this point, it’s probably not going to cause any issues with getting the training done either. Outside of that unique situation, there may not be a need for extending the rest period beyond 5 minutes.

On to the next outcome of concern, hypertrophy.

How Long Should Rest Periods Be For Hypertrophy?

While there is definitely overlap in the training for strength and hypertrophy, there are some nuances in the modifiable training variables of a program that can be adjusted to optimize one versus the other. 

Hypertrophy is defined in most studies as an increase in total mass of a muscle, or a muscle’s cross sectional area (CSA). This is driven primarily by mechanical tension from lifting weights, which then drives increases in muscle protein synthesis. If we want to maximize the amount of mechanical tension our muscles can produce, then we need to preserve our force producing capabilities. Much like with strength training, when rest periods are too short fatigue may prevent us from producing high levels of force. If rest periods are too long, however, the workout may just be impractical from a time perspective thus limiting the amount of volume a trainee can accumulate. 

For hypertrophy outcomes, we recommend rest periods of between 2-4 minutes.

Resistance training relies heavily on anaerobic pathways to create energy (ATP) for the muscles, which results in the buildup of metabolic byproducts such as hydrogen ions, inorganic phosphate, lactate, and others. Research has continually shown that these metabolic byproducts are associated with muscle hypertrophy, though it is not clear they’re directly causal. 

Anytime the muscles are contracting during resistance training, they’re producing these metabolites, making it hard to determine whether metabolites contribute to hypertrophy or if it’s just the mechanical force from muscular contractions. Based on the present data, it appears the majority of muscular hypertrophy is caused by mechanical signals, whereas metabolites may have an indirect role, if any at all.

Nonetheless, it’s been hypothesized that people focusing on gaining muscle size might do better with shorter rest periods in an effort to increase this metabolic stress, thereby increasing an anabolic signal to the muscle. Of course, if these shorter rest periods negatively impact the volume-load used for a training session, it could limit total mechanical tension. Let’s take a look at the research on this.

In one study, 16 men did 4 sets of leg press and 4 sets of leg extensions at 75% of their 1RM to failure. One group rested a minute between sets and the other rested 5 minutes between sets. Biopsies of the leg were taken after the workout, which showed that muscle protein synthesis increased 152% in the 5 minute group, whereas it only went up 76% in the 1-minute group.¹²

Another mechanistic study looked at men training with either 2 or 5 minutes of rest over 6 months to see if the shorter rest periods produced greater increases in lactate or hormones associated with muscle growth. The levels of growth hormone, testosterone, and cortisol were measured across the 6 months. This was a crossover study, where each subject trained with 2 minute rest periods for 3 months and then 5 minute rest periods for the other 3 months to see if there were differences within the individual with different training programs. In this study, there were no differences in blood lactate, growth hormone, testosterone levels, or cortisol levels with the different rest periods. Both groups increased strength and hypertrophy, but there were no differences based on the rest periods.⁹

Looking just at these mechanisms of hypertrophy like muscle protein synthesis levels and hormone levels can be misleading, so let’s talk about real world hypertrophy outcomes in subjects.

A 2016 study had 23 men train 3 times per week for 8 weeks where they did 3 sets of 8 to 12 reps for 7 exercises per session, resting for either 1 or 3 minutes. At the end of 8-weeks, the group resting 3 minutes had done more volume, lifted heavier weights, and had significantly more growth in their biceps, triceps, and quadriceps muscles. They also had double the improvement in their 1RM squat, up 15% compared to 7.5% in the 1-minute rest group. Those resting 3 minutes improved their 1RM bench by 12.7%, compared to 4% in the 1-minute group. Of note, the researchers tested the subjects’ muscular endurance by having them do 50% of their 1RM bench and squat to failure. Those resting 3 minutes improved their performance by 10% more than the short rest group.¹³

In a meta analysis of 6 studies looking at the effect of rest period length on hypertrophy, mostly in untrained men lifting 4 times per week for 8 weeks or so, almost all of the results favored the longer rest period for driving more hypertrophy. Of note, the short rest periods were usually between 20 to 60 seconds and the long rest periods were up to 4 minutes in length.¹⁴ 

Overall, the data on rest periods and hypertrophy seems to highlight a similar relationship to that seen in strength training. Longer rest periods seem to lead to improvements in muscle gain, likely because people can do more volume and possibly because less fatigue is being generated. There’s a point of diminishing returns though, where even longer rest periods – say 5 minutes – don’t necessarily do better than something more modest like 3 minutes. There may also be an effect specific to exercise selection – with exercises using heavier loads and more muscle mass like squats and bench presses likely doing better with more rest. Isolation, or single-joint movements, that moves relatively less muscle mass and lower absolute loads on the other hand may do better with shorter rest periods of 2 to 3 minutes. Again, the amount of rest people need between sets to maintain volume (reps per set) and exertion level (RPE or RIR) is likely trainable. As people get more and more fit, they may be able to decrease their rest periods a bit without much of an issue. 

Other Factors Influencing Your Ideal Rest Time

Exercise Type

Different exercise types may require more rest than others. Exercises using more weight, more volume in the form of reps and sets, and more muscle mass can generate more fatigue thus requiring more rest. For example, many people will report feeling less fatigue from a set of biceps curls as compared to a set of 10 heavy squats. The biceps muscle is simply less muscle mass than the combined mass of the quadriceps, gluteals, and back so the rest required here would be lower. We still recommend to rest within the 2-4 minute range for hypertrophy or the 2-5 minute range for strength but where you fall in that recommendation may vary based on the exercise chosen. 

For lower intensity, single-joint or isolation exercises like lateral raises, triceps pushdowns, or calf raises it may be more appropriate to rest closer to that 2 minute mark where as for higher intensity, compound movements like squats, deadlifts, and bench presses more maximizing that rest period is recommended. 

Training Experience 

A lifter’s training experience may also affect their required rest times. One of the adaptations the body makes to training is increased efficiency and capacity of the energy systems that supply muscle contraction. That being said, the absolute loads and relative intensities being used by novice lifters and advanced lifters could be vastly different. So, of course, there is some nuance here in applying rest periods to lifters with different experience levels.

Novice Lifters

New lifters may require more rest than advanced trainees because their ATP/PCr and anaerobic glycolytic systems are not as adept at regenerating ATP. They may have smaller PCr and glycogen stores and reduced buffering capacity of lactate and hydrogen ions as compared to advanced trainees. This may mean that they may need to rest longer than a trained individual for bioenergetic purposes.¹⁵ All of that said, newer exercisers will usually use smaller absolute loads and train with a lower relative intensity – RPE. This may mean that newer lifters can get away with slightly less rest because the fatigue they are generating is less. We recommend novice lifters to still abide by the recommendations of 2-4 minutes for hypertrophy training and 2-5 minutes for strength training; but where they fall within that window has to do with them feeling as if they are ready for another set. 

Advanced Lifters

Advanced lifters have spent a long time conditioning their ATP/PCr and anaerobic glycolytic energy system so they have made adaptations that lead to increased efficiency and capacity of these systems. They will have larger ATP, PCr, and glycogen stores as compared to untrained athletes. They will also have greater activity of the enzymes involved in these systems like phosphofructokinase and creatine kinase making these energy systems more efficient.¹⁶ Advanced lifters, however, will likely be using larger absolute loads and may train at higher relative intensities, or RPEs which may require longer rest periods. We recommend advanced lifters also to abide by the recommendations of 2-4 minutes for hypertrophy training and 2-5 minutes for strength training. A subtle difference here may be for strength athletes peaking for a meet when training volume is very low may rest for greater than 5 minutes between singles at very high percentages of 1RM and high RPEs. In this unique scenario, the problem of not having enough time to complete the required volume doesn’t exist as volume is typically quite low during this period of training. 

Short on time? Reduce Your Training Time with Supersets

A superset is when two different exercises are completed back-to-back with minimal rest. In the situation where there is limited time to complete a workout, one option is to use a superset. If done properly, a superset can reduce total training time, while still maintaining total training volume and average intensity. With supersets you can use your rest time to train a totally different muscle group. 

Supersets come in three major flavors, agonist-agonist, agonist-antagonist, and alternate-peripheral. 

Agonist-Agonist supersets are where an individual trains the same muscle group twice in a row with two exercises like doing bench press then flies. This is traditionally used in body building to enhance the fatigue in the local musculature – trying to take the pecs “past” failure. This approach typically produces higher degrees of muscle damage and greater reductions in both training volume and force production, particularly on the second exercise of the superset. 

When compared to splitting them up and just doing straight sets, the reduction in volume tends to produce worse outcomes related to hypertrophy. If total volume is maintained, then hypertrophy outcomes are likely to be similar.

However, strength outcomes still appear to be worse since loading and force production are compromised. To summarize, agonist-agonist supersets can be used for hypertrophy if total volume is maintained, but they are not generally a good option for strength. 

Agonist-antagonist supersets are where two exercises that train opposing muscle groups are paired together, such as bench press and then a row. This approach can be very useful for reducing time in training without compromising outcomes, as training volume and force production appear to be maintained because there is little overlapping fatigue from the opposing muscle groups. When you’re performing a bench press, and then you perform a row, and then you rest two minutes, you’re not only getting the two minutes of rest for your pecs, anterior deltoids, and triceps. Rather, you’re also resting the active muscles in the bench press during the rows, and the active muscles in the rows during the bench press. 

The major application for agonist-antagonist supersets would be hypertrophy, as a lot of volume can be performed for a given amount of time. It’s okay for strength as well, but probably not a great option for maximal strength development as components of central fatigue may impact your force production. 

Alternate-peripheral supersets are where two completely unrelated exercises are paired together – a squat and overhead press. When looking at alternate-peripheral supersets that are not taken to failure, e.g. to RPE 6-8 for example, the training volume, peak loads, and force production tend to be maintained. 

This can be a useful approach for general strength development, but probably isn’t best for powerlifting- or max-strength specific training. The overall cardiorespiratory demand of doing two heavy compound exercises, especially if you’re strong, which train a lot of the muscle groups in the body, can cause some loss of volume and force production, which would be undesirable if someone is trying to pull out all the stops for strength development.¹⁷

Implementing and Adjusting Rest Periods in Your Program

To gain the most strength:

• Rest periods of 2-5 minutes produce better results as compared to shorter rest periods due to the accumulation of more volume at the appropriate exertion level.
• Shorter rest periods may impact the total volume able to be performed due to intraset fatigue and longer rest periods may impact the total volume performed due to time constraints.
• Compound exercises like squats, deadlifts, and bench presses that move more total muscle mass and typically move larger absolute loads may require rest periods that are longer, 4-5 minutes as compared to single joint exercises like biceps curls or lateral raises that may require only 2-3 minutes of rest.
• Rest periods of greater than 5 minutes may benefit performance in the short term, which may be appropriate for strength athletes peaking for a meet or a 1RM test. 

To gain the most muscle:

• Rest periods of 2-4 minutes produce better results as compared to shorter or longer rest periods due to the accumulation of volume at the appropriate exertion level. 
• Shorter rest periods, while possibly increasing metabolic stress, may negatively impact the accumulation of volume which limits mechanical tension. Longer rest periods may negatively impact the amount of volume that can be accumulated in a session due to time constraints.
• Compound exercises like squats, deadlifts, and bench presses that move more total muscle mass and typically move larger absolute loads may require rest periods that are longer, 4-5 minutes as compared to single joint exercises like biceps curls or lateral raises that may require only 2-3 minutes of rest.

References

1. Baird, M. F., Graham, S. M., Baker, J. S., & Bickerstaff, G. F. (2012). Creatine-kinase- and exercise-related muscle damage implications for muscle performance and recovery. Journal of nutrition and metabolism, 2012, 960363. https://doi.org/10.1155/2012/960363
2. Zając, A., Chalimoniuk, M., Maszczyk, A., Gołaś, A., & Lngfort, J. (2015). Central and Peripheral Fatigue During Resistance Exercise – A Critical Review. Journal of human kinetics, 49, 159–169. https://doi.org/10.1515/hukin-2015-0118
3. McMahon, S., & Jenkins, D. (2002). Factors affecting the rate of phosphocreatine resynthesis following intense exercise. Sports medicine (Auckland, N.Z.), 32(12), 761–784. https://doi.org/10.2165/00007256-200232120-00002
4. Wan, J. J., Qin, Z., Wang, P. Y., Sun, Y., & Liu, X. (2017). Muscle fatigue: general understanding and treatment. Experimental & molecular medicine, 49(10), e384. https://doi.org/10.1038/emm.2017.194
5. Jukic, I., Ramos, A. G., Helms, E. R., McGuigan, M. R., & Tufano, J. J. (2020). Acute Effects of Cluster and Rest Redistribution Set Structures on Mechanical, Metabolic, and Perceptual Fatigue During and After Resistance Training: A Systematic Review and Meta-analysis. Sports medicine (Auckland, N.Z.), 50(12), 2209–2236. https://doi.org/10.1007/s40279-020-01344-2
6. Grgic, J., Schoenfeld, B.J., Skrepnik, M. et al. Effects of Rest Interval Duration in Resistance Training on Measures of Muscular Strength: A Systematic Review. Sports Med 48, 137–151 (2018). https://doi.org/10.1007/s40279-017-0788-x
7. Robinson, J. M., Stone, M. H., Johnson, R. L., Penland, C. M., Warren, B. J., & Lewis, R. D. (1995). Effects of different weight training exercise/rest intervals on strength, power, and high intensity exercise endurance. Journal of Strength & Conditioning Research, 9(4), 216–221. https://doi.org/10.1519/00124278-199511000-00002
8. de Salles, B. F., Simão, R., Miranda, H., Bottaro, M., Fontana, F., & Willardson, J. M. (2010). Strength increases in upper and lower body are larger with longer inter-set rest intervals in trained men. Journal of science and medicine in sport, 13(4), 429–433. https://doi.org/10.1016/j.jsams.2009.08.002
9. Ahtiainen, J. P., Pakarinen, A., Alen, M., Kraemer, W. J., & Häkkinen, K. (2005). Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men. Journal of strength and conditioning research, 19(3), 572–582. https://doi.org/10.1519/15604.1
10. Santana, W. J., Silva, E. M., & Silva, G. P. (2023). Recovery between sets in strength training: Systematic review and meta-analysis. Revista Brasileira de Medicina do Esporte. https://www.scielo.br/j/rbme/a/Y9vYkwhHhbzKcKNSG9Ft85s/?format=pdf&lang=en
11. González-Hernández, J. M., Jimenez-Reyes, P., Janicijevic, D., Tufano, J. J., Marquez, G., & Garcia-Ramos, A. (2023). Effect of different interset rest intervals on mean velocity during the squat and bench press exercises. Sports biomechanics, 22(7), 834–847. https://doi.org/10.1080/14763141.2020.1766102
12. McKendry, J., Pérez-López, A., McLeod, M., Luo, D., Dent, J. R., Smeuninx, B., Yu, J., Taylor, A. E., Philp, A., & Breen, L. (2016). Short inter-set rest blunts resistance exercise-induced increases in myofibrillar protein synthesis and intracellular signalling in young males. Experimental physiology, 101(7), 866–882. https://doi.org/10.1113/EP085647
13. Schoenfeld, B. J., Pope, Z. K., Benik, F. M., Hester, G. M., Sellers, J., Nooner, J. L., Schnaiter, J. A., Bond-Williams, K. E., Carter, A. S., Ross, C. L., Just, B. L., Henselmans, M., & Krieger, J. W. (2016). Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men. Journal of strength and conditioning research, 30(7), 1805–1812. https://doi.org/10.1519/JSC.0000000000001272
14. Grgic, J., Lazinica, B., Mikulic, P., Krieger, J. W., & Schoenfeld, B. J. (2017). The effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy: A systematic review. European Journal of Sport Science, 17(8), 983–993. https://doi.org/10.1080/17461391.2017.1340524
15. Ross, A., Leveritt, M., & Riek, S. (2001). Neural influences on sprint running: training adaptations and acute responses. Sports medicine (Auckland, N.Z.), 31(6), 409–425. https://doi.org/10.2165/00007256-200131060-00002
16. Kaczor, J. J., Ziolkowski, W., Popinigis, J., & Tarnopolsky, M. A. (2005). Anaerobic and aerobic enzyme activities in human skeletal muscle from children and adults. Pediatric research, 57(3), 331–335. https://doi.org/10.1203/01.PDR.0000150799.77094.DE
17. Zhang, X., Weakley, J., Li, H., Li, Z., & García-Ramos, A. (2025). Superset Versus Traditional Resistance Training Prescriptions: A Systematic Review and Meta-analysis Exploring Acute and Chronic Effects on Mechanical, Metabolic, and Perceptual Variables. Sports medicine (Auckland, N.Z.), 55(4), 953–975. https://doi.org/10.1007/s40279-025-02176-8

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Obesity is a complex, chronic disease influenced by multiple factors. It is currently defined as a condition characterized by an excessive accumulation of body fat that leads to abnormal functioning of the fat, or adipose tissue, as well as abnormal physical forces on the body due to the excess fat mass. Together, these mechanisms result in harmful metabolic, biomechanical, and psychosocial health consequences such as diabetes, heart disease, chronic musculoskeletal pain, depression, and more.

As with any other disease process, the ability to identify and diagnose obesity is important to properly treat people with obesity. As it currently stands, there are several ways to assess obesity and body fat levels to determine the risk an individual has for obesity related illnesses.

Dual-energy X-ray absorptiometry (DEXA), hydrostatic (underwater) weighing, and air displacement plethysmography (Bod-Pod) methods can assess an individual’s body fat levels. However, these tests are expensive and inaccessible for most individuals making them an impractical choice to assess for obesity levels and re-assess to track progress. Going one step further, these methods become increasingly impractical to apply to large populations of people for research or public health policy informing purposes.

For this reason, simple screening tools that require only a few measurements and a calculation have gained popularity due to their ability to diagnose people with obesity without the need of specialized equipment or a significant financial or time burden. This makes an assessment of obesity take seconds in a doctor’s office or research lab.

Most people are familiar with one of these screening tools; Body Mass Index, or BMI. While BMI has its pros and cons, it has had staying power as a screening tool due to its ease of use. To calculate BMI you only need to know someone’s height, measured in meters (m), and weight, measured in kilograms (kg). One of the most common, and important, critiques of BMI is that it does not take into account where the weight is located. Is the extra weight in the muscle of the quads and biceps or around the waistline as fat tissue?

In recent years a new screening tool to assess health risk related to obesity has emerged known as the Body Roundness Index. The Body Roundness Index takes into account where the excess weight is located, as opposed to just assessing whether or not it is there. Because of this advantage over BMI, many are calling for it to replace BMI. But, should it?

In this article we’ll discuss what the Body Roundness Index is, how and why it was developed, how to measure it, the latest science on this new tool, and opine about whether or not it should replace BMI. 

You can also listen to our podcast discussion on BRI: Body Roundness Index – Episode #316 of the Barbell Medicine Podcast

Why should we assess obesity by more than just weight?

As stated above, obesity is a complex and multifactorial disease. We view excess body fat or adipose tissue as a sign of the underlying disease of obesity. This underlying disease results in the person achieving energy balance at a higher-than-healthy body fat level. Ideally, appetite and food-related behaviors would match people’s energy and nutrition needs. For example, as energy stores (body fat) increases, appetite and energy intake are suppressed, spontaneous physical activity increases, and vice versa. However, in the setting of obesity, these signals are often mismatched.

The rates of those with overweight and obesity are increasing in every single country in the world. Globally, over 2 billion adults are overweight and over 650 million have obesity. It’s predicted that this number will soon grow to over 1 billion adults with obesity worldwide.^1,2

The body mass index (BMI) aims to screen for obesity, which is a disease characterized by excess body fat. While there are other tools to assess an individual’s body fat, like those mentioned above, these assessments typically do not account for where the excess fat is located. 

Body Mass Index, or BMI, replaced a previous calculation known as Ideal Body Weight. It is a quick calculation that could be done for anyone while visiting a doctor’s office and also for research purposes when attempting to quantify health for large populations of people. All that is needed to calculate BMI is a person’s height measured in meters (m) and weight in kilograms (kg). 

For screening and diagnostic purposes, a BMI of less-than 18.5 corresponds to an individual at risk for being underweight, whereas a BMI of 25 is used for overweight, and a BMI of 30 or higher is used for obesity. The current guidelines also recognize that individuals of different ethnic backgrounds may require different cutoff points to screen for health risks due to excess body fat. For example, it is suggested that a BMI cutoff point value of ≥23 kg/m² should be used in the screening and confirmation of excess adiposity in South Asian, Southeast Asian, and East Asian adults. 

As a screening and diagnostic tool, BMI is just okay.

Many critics of BMI claim that it overdiagnoses obesity in people that are heavily muscled. Being that only 24% of the US population meets the minimum physical activity guidelines for both conditioning and strength training, this is likely not a widespread issue.³ In fact, BMI has a specificity of 95-99%.³¹ This means that it has very few false positives. As far as medical tests go, that is very good. This means that 95-99% of people with a BMI of greater than 30 truly do have obesity. On the other hand, BMI is not a very sensitive test. When a test is 100% sensitive, it catches everyone who has the condition being tested for. We don’t see this with BMI. For example, there are people who have a BMI of less than 30 but are still considered to be carrying too much body fat. Assessments of BMI have found that it has a sensitivity of less than 36% for men and 49% of women. So BMI actually misses almost half of people who are carrying too much body fat.

Therefore, the biggest problem with using BMI alone is that it tends to miss far more individuals who carry excess body fat, rather than inappropriately diagnosing those who are actually too muscular. To go one step further, BMI does not take into account where the bodyfat is located. 

So, why does the location of body fat even matter? Fat is fat, right?

Location, Location, Location: Fat location can predict health risk

Generally speaking, humans distribute their body fat in two major sites within the body. Body fat can be stored subcutaneously, or under the skin, or viscerally in the abdomen around the organs. The relative amounts of body fat stored in a particular location varies significantly among individuals based on sex, age, race, activity level, the total amount of body fat, and even certain medications.

Excess visceral fat in the abdomen is recognized as an established risk factor that is strongly correlated with cardiovascular events like heart attacks and stroke, type 2 diabetes, and all-cause mortality. In contrast, the same level of body fat located elsewhere, such as the arms, legs, and buttocks, does not produce the same risk. There is a growing consensus that visceral fat is much more dangerous to health than subcutaneous fat, since it entails more risk for diseases.⁶ Abdominal fat in particular produces a number of inflammatory hormones called adipokines that are involved in obesity-related chronic diseases.¹⁰

As we already discussed, BMI only takes into account a person’s height and weight, but not where the excess fat is located when classifying obesity levels. To overcome these limitations, most guidelines recommend also obtaining a waist circumference measurement to gather information about where an individual’s body fat is distributed. This seems to more accurately determine an individual’s risk of health problems from carrying too much body fat.⁸

To measure your waist circumference, place a measuring tape directly against the skin in a circle around the abdomen at the level of the navel. Ensure the measuring tape is flat and even, not high or low on one side or another, and make sure it is not pressing into the skin. This measurement only takes a moment and can add to BMI to get a better picture of health risk related to obesity. 

Not only is this assessment convenient, but it is also very accurate. Waist circumference measurements are highly correlated to the amount of abdominal fat in both men and women as measured by MRI and CT scans.^44,25 Being that MRI and CT scans are expensive and inaccessible for many, doctor assisted or self-measured waist circumference measurements present a great opportunity to get a clearer picture of health risk. After instruction, self-measured waist circumference values are both accurate and reproducible, so people should feel empowered to do these assessments on their own.⁴⁵

For an individual with a BMI between 23 and 35, it is recommended to also obtain a waist circumference to see where this weight is located. A waist circumference of at least 102 centimeters, or approximately 40 inches, in men indicates abdominal obesity, though a lower cut off of 94 cm, or 37 inches, has been suggested. In women, a waist circumference of 88 centimeters, or approximately 35 inches, indicates abdominal obesity, with a lower target of 80 cm, or 32 inches, being suggested.^11,5 

Generally speaking, combining BMI and waist circumference together do a pretty good job of identifying those at risk of disease from carrying too much body fat, outperforming metrics like waist to hip ratio, waist to height ratio, and BMI alone.¹⁶ This leads to people having two scores assessing obesity, BMI and a waist circumference. Deciding what these numbers mean alone and then together presented some diagnostic challenges. 

In an attempt to simplify this process, researchers tried to combine BMI and waist circumference into one screening tool that computes a single value which could subsequently be used to diagnose obesity.¹⁷

This led to the eventual creation of the relatively new screening tool, the Body Roundness Index.

The body roundness index aims to model an individual’s body shape to predict their body composition and body fat distribution in an effort to better characterize an individual’s health risk from excess body fat.¹⁸ Theoretically, assuming the shape of the body as an ellipse with the long axis being represented by height and the short axis by waist circumference, the body roundness index can be calculated as the eccentricity of this ellipse via human modeling on a scale from 1 to 20, with 1 being a more narrow and 20 being more round. As you can see below, as waist circumference increases, the ellipse becomes more round.

The variables used in the calculation include: an individual’s height, age, weight, sex, race, and waist circumference. This makes for an accurate picture of disease risk from excess adipose tissue as all of these things tend to influence both body composition and body fat distribution. The formula is quite complex, but the linked Body Roundness Index calculator will take care of the math for you. Calculate your Body Roundness Index here.

In the general population, the average body roundness index is 5.62, which has gone up over the past 20 years following the rise in obesity. The body roundness index was higher in Mexican American individuals, followed by non-hispanic black individuals, then non-hispanic white individuals. A similar trend was also observed based on education, with those obtaining a college education having the lowest body roundness index. 

A data set on over 30,000 adults in the United states shows an interesting relationship between body roundness index and health risk. Body roundness index scores of 4.5 to 5.5 are correlated with the lowest risk of mortality from all causes. Interestingly, body roundness scores of less than 3.4 have a 25% increased risk of mortality from all causes. Research suggests that a very low score may indicate sarcopenia, or muscle loss, frailty, or malnutrition.⁴³ Those with a body roundness index score of greater than 6.9 have a 50% increased risk of mortality from all causes, which is attributed to excess body fat.^38,21

Thanks to the Body Roundness Index, we now have a new screening tool that assesses health risk based not only on excess adipose tissue but also where that tissue is located all packaged into one number.

With all of this in mind, it seems that the Body Roundness Index is a more accurate screening tool than what has been used in the past. Research has demonstrated that it appears to work better than either BMI or waist circumference alone when it comes to predicting risk of heart disease, metabolic syndrome, type 2 diabetes, reduced kidney function, and even all cause mortality. This is especially true in populations where the standard BMI cutoffs, e.g., 25 for overweight and 30 for obesity, are already known to be off, such as those of Asian descent and/or elderly individuals.^{22, 28, 32, 30, 46}

So, should Body Roundness Index be the new BMI? Should we just throw BMI away and forget it ever existed?  

Should BRI replace BMI?

While the Body Roundness Index is a more accurate tool, how we use it will determine whether or not it has any impact on actually managing obesity. 

There are a few potential positives to widespread adoption of the Body Roundness Index and areas of future research that could improve its impact on obesity management.

First, the positives. As already detailed above it appears to be a better screening tool than BMI and waist circumference alone. If doctors, public health officials, or researchers are going to be making decisions about a person’s health or public policy it certainly makes sense to have the best possible data to work with. 

In addition, it gives one value that correlates to health risk as opposed to two. While this may not seem like that big of a deal, consider the implications of seeing hundreds of patients a week or working with data sets of tens of thousands of people. For the health system and research system as a whole, working with one number makes sense from an efficiency standpoint. 

Lastly, using Body Roundness Index circumvents the negative association most folks have with BMI. Even people outside of the health and fitness space may have negative beliefs or feelings towards BMI which could turn them away from even considering monitoring it with their health care provider. Using the Body Roundness Index instead could facilitate conversations around the topic of obesity in the doctor’s office in a more productive manner which could lead to better outcomes. 

Will BRI improve the management of obesity?

Widespread adoption of the Body Roundness Index could simplify the diagnosis and quantification of obesity related health risk which could lead to better management of the disease. If the Body Roundness Index replaced BMI entirely, it would guarantee that people’s waist circumference and ethnicity are taken into consideration when attempting to quantify obesity related disease risk. Future research will hopefully tell us what amount of change in body roundness index leads to health risk changes and over what time frame. Overall, the Body Roundness Index seems like a very useful and accurate tool based on a solid scientific foundation. 

References

1. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
2. Boutari C, Mantzoros CS. A 2022 update on the epidemiology of obesity and a call to action: as its twin COVID-19 pandemic appears to be receding, the obesity and dysmetabolism pandemic continues to rage on. Metabolism. 2022 Aug;133:155217. doi: 10.1016/j.metabol.2022.155217. Epub 2022 May 15. PMID: 35584732; PMCID: PMC9107388.
3. Bhattacharyya, M., Miller, L. E., Miller, A. L., Bhattacharyya, R., & Herbert, W. G. (2024). Disparities in adherence to physical activity guidelines among US adults: A population-based study. Medicine, 103(36), e39539. https://doi.org/10.1097/MD.0000000000039539
4. Ciemins EL, Joshi V, Cuddeback JK, Kushner RF, Horn DB, Garvey WT. Diagnosing Obesity as a First Step to Weight Loss: An Observational Study. Obesity (Silver Spring). 2020 Dec;28(12):2305-2309. doi: 10.1002/oby.22954. Epub 2020 Oct 7. PMID: 33029901; PMCID: PMC7756722.
5. Garvey WT, Mechanick JI, Brett EM, Garber AJ, Hurley DL, Jastreboff AM, Nadolsky K, Pessah-Pollack R, Plodkowski R; Reviewers of the AACE/ACE Obesity Clinical Practice Guidelines. AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY COMPREHENSIVE CLINICAL PRACTICE GUIDELINES FOR MEDICAL CARE OF PATIENTS WITH OBESITY. Endocr Pract. 2016 Jul;22 Suppl 3:1-203. doi: 10.4158/EP161365.GL. Epub 2016 May 24. PMID: 27219496.
6. Gruzdeva O, Borodkina D, Uchasova E, Dyleva Y, Barbarash O. Localization of fat depots and cardiovascular risk. Lipids Health Dis. 2018 Sep 15;17(1):218. doi: 10.1186/s12944-018-0856-8. PMID: 30219068; PMCID: PMC6138918.
7. Romero-Corral A, Somers VK, Sierra-Johnson J, Thomas RJ, Collazo-Clavell ML, Korinek J, Allison TG, Batsis JA, Sert-Kuniyoshi FH, Lopez-Jimenez F. Accuracy of body mass index in diagnosing obesity in the adult general population. Int J Obes (Lond). 2008 Jun;32(6):959-66. doi: 10.1038/ijo.2008.11. Epub 2008 Feb 19. PMID: 18283284; PMCID: PMC2877506.
8. Mulligan AA, Lentjes MAH, Luben RN, Wareham NJ, Khaw KT. Changes in waist circumference and risk of all-cause and CVD mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study. BMC Cardiovasc Disord. 2019 Oct 28;19(1):238. doi: 10.1186/s12872-019-1223-z. PMID: 31660867; PMCID: PMC6819575.
9. Abate N, Garg A, Peshock RM, Stray-Gundersen J, Grundy SM. Relationships of generalized and regional adiposity to insulin sensitivity in men. J Clin Invest. 1995 Jul;96(1):88-98. doi: 10.1172/JCI118083. PMID: 7615840; PMCID: PMC185176.
10. Antonopoulos AS, Tousoulis D. The molecular mechanisms of obesity paradox. Cardiovasc Res. 2017 Jul 1;113(9):1074-1086. doi: 10.1093/cvr/cvx106. PMID: 28549096
11. Jensen MD. American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. Circulation. 2014 Jun 24;129(25 Suppl 2):S102-38. doi: 10.1161/01.cir.0000437739.71477.ee. Epub 2013 Nov 12. Erratum in: Circulation. 2014 Jun 24;129(25 Suppl 2):S139-40. PMID: 24222017; PMCID: PMC5819889.
12. Romero-Corral A, Somers VK, Sierra-Johnson J, Thomas RJ, Collazo-Clavell ML, Korinek J, Allison TG, Batsis JA, Sert-Kuniyoshi FH, Lopez-Jimenez F. Accuracy of body mass index in diagnosing obesity in the adult general population. Int J Obes (Lond). 2008 Jun;32(6):959-66. doi: 10.1038/ijo.2008.11. Epub 2008 Feb 19. PMID: 18283284; PMCID: PMC2877506.Sommer I, Teufer B, Szelag M, Nussbaumer-Streit B, Titscher V, Klerings I, Gartlehner G. The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis. Sci Rep. 2020 Jul 29;10(1):12699. doi: 10.1038/s41598-020-69498-7. PMID: 32728050; PMCID: PMC7391719
13. Mulligan AA, Lentjes MAH, Luben RN, Wareham NJ, Khaw KT. Changes in waist circumference and risk of all-cause and CVD mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study. BMC Cardiovasc Disord. 2019 Oct 28;19(1):238. doi: 10.1186/s12872-019-1223-z. PMID: 31660867.
14. Abate N, Garg A, Peshock RM, Stray-Gundersen J, Grundy SM. Relationships of generalized and regional adiposity to insulin sensitivity in men. J Clin Invest. 1995 Jul;96(1):88-98. doi: 10.1172/JCI118083. PMID: 7615840.
15. Antonopoulos AS, Tousoulis D. The molecular mechanisms of obesity paradox. Cardiovasc Res. 2017 Jul 1;113(9):1074-1086. doi: 10.1093/cvr/cvx106. PMID: 28549096.sThompson D, Karpe F, Lafontan M, Frayn K. Physical activity and exercise in the regulation of human adipose tissue physiology. Physiol Rev. 2012 Jan;92(1):157-91. doi: 10.1152/physrev.00012.2011. PMID: 2229865Grundy SM, Neeland IJ, Turer AT, Vega GL. Waist circumference as measure of abdominal fat compartments. J Obes. 2013;2013:454285. doi: 10.1155/2013/454285.PMID: 23762536.
16. Sommer I, Teufer B, Szelag M, Nussbaumer-Streit B, Titscher V, Klerings I, Gartlehner G. The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis. Sci Rep. 2020 Jul 29;10(1):12699. doi: 10.1038/s41598-020-69498-7. PMID: 32728050.
17. Zhu S, Heshka S, Wang Z, Shen W, Allison DB, Ross R, Heymsfield SB. Combination of BMI and Waist Circumference for Identifying Cardiovascular Risk Factors in Whites. Obes Res. 2004 Apr;12(4):633-45. PMID: 15090631.
18. Thomas DM, Bredlau C, Bosy-Westphal A, Mueller M, Shen W, Gallagher D, Maeda Y, McDougall A, Peterson CM, Ravussin E, Heymsfield SB. Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model. Obesity (Silver Spring). 2013 Nov;21(11):2264-71. doi: 10.1002/oby.20408. Epub 2013 Jun 11. PMID: 23519954; PMCID: PMC3692604.
19. https://webfce.com/bri-calculator/
20. Zhang X, Ma N, Lin Q, et al. Body Roundness Index and All-Cause Mortality Among US Adults. JAMA Netw Open. 2024;7(6):e2415051. doi:10.1001/jamanetworkopen.2024.15051 Zhang X, Ma N, Lin Q, et al. Body Roundness Index and All-Cause Mortality Among US Adults. JAMA Netw Open. 2024;7(6):e2415051. doi:10.1001/jamanetworkopen.2024.15051 Rico-Martín S, Calderón-García JF, Sánchez-Rey P, Franco-Antonio C, Martínez Alvarez M, Sánchez Muñoz-Torrero JF. Effectiveness of body roundness index in predicting metabolic syndrome: A systematic review and meta-analysis. Obes Rev. 2020 Jul;21(7):e13023. doi: 10.1111/obr.13023. Epub 2020 Apr 8. PMID: 32267621.
21. Zhou D, Liu X, Huang Y, Feng Y. A nonlinear association between body roundness index and all-cause mortality and cardiovascular mortality in general population. Public Health Nutr. 2022 Nov;25(11):3008-3015. doi: 10.1017/S1368980022001768. Epub 2022 Aug 19. PMID: 35983642; PMCID: PMC9991644.
22. Cai X, Song S, Hu J, Zhu Q, Yang W, Hong J, Luo Q, Yao X, Li N. Body roundness index improves the predictive value of cardiovascular disease risk in hypertensive patients with obstructive sleep apnea: a cohort study. Clin Exp Hypertens. 2023 Dec 31;45(1):2259132. doi: 10.1080/10641963.2023.2259132. Epub 2023 Oct 8. PMID: 37805984.
23. Wu L, Pu H, Zhang M, Hu H, Wan Q. Non-linear relationship between the body roundness index and incident type 2diabetes in Japan: a secondary retrospective analysis. J Transl Med. 2022 Mar 7;20(1):110. doi: 10.1186/s12967-022-03321-x. PMID: 35255926; PMCID: PMC8900386.
24. Zhang Y, Gao W, Ren R, Liu Y, Li B, Wang A, Tang X, Yan L, Luo Z, Qin G, Chen L, Wan Q, Gao Z, Wang W, Ning G, Mu Y.Body roundness index is related to the low estimated glomerular filtration rate in Chinese population: A cross-sectional study. Front Endocrinol (Lausanne). 2023 Mar 28;14:1148662. doi: 10.3389/fendo.2023.1148662. PMID: 37056676; PMCID: PMC10086436.
25. Zhu S, Heshka S, Wang Z, Shen W, Allison DB, Ross R, Heymsfield SB. Combination of BMI and Waist Circumference for Identifying Cardiovascular Risk Factors in Whites. Obes Res. 2004 Apr;12(4):633-45. doi: 10.1038/oby.2004.73. PMID: 15090631.
26. Thomas DM, Bredlau C, Bosy-Westphal A, Mueller M, Shen W, Gallagher D, Maeda Y, McDougall A, Peterson CM, Ravussin E, Heymsfield SB. Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model. Obesity (Silver Spring). 2013 Nov;21(11):2264-71. doi: 10.1002/oby.20408. Epub 2013 Jun 11. PMID: 23519954; PMCID: PMC3692604.
27. https://webfce.com/bri-calculator
28. Rico-Martín S, Calderón-García JF, Sánchez-Rey P, Franco-Antonio C, Martínez Alvarez M, Sánchez Muñoz-Torrero JF. Effectiveness of body roundness index in predicting metabolic syndrome: A systematic review and meta-analysis. Obes Rev. 2020 Jul;21(7):e13023. doi: 10.1111/obr.13023. Epub 2020 Apr 8. PMID: 32267621.
29. Wu L, Pu H, Zhang M, Hu H, Wan Q. Non-linear relationship between the body roundness index and incident type 2 diabetes in Japan: a secondary retrospective analysis. J Transl Med. 2022 Mar 7;20(1):110. doi: 10.1186/s12967-022-03321-x. PMID: 35255926; PMCID: PMC8900386.
30. Zhang Y, Gao W, Ren R, Liu Y, Li B, Wang A, Tang X, Yan L, Luo Z, Qin G, Chen L, Wan Q, Gao Z, Wang W, Ning G, Mu Y. Body roundness index is related to the low estimated glomerular filtration rate in Chinese population: A cross-sectional study. Front Endocrinol (Lausanne). 2023 Mar 28;14:1148662. doi: 10.3389/fendo.2023.1148662. PMID: 37056676; PMCID: PMC10086436.
31. Romero-Corral A, Somers VK, Sierra-Johnson J, Thomas RJ, Collazo-Clavell ML, Korinek J, Allison TG, Batsis JA, Sert-Kuniyoshi FH, Lopez-Jimenez F. Accuracy of body mass index in diagnosing obesity in the adult general population. Int J Obes (Lond). 2008 Jun;32(6):959-66. doi: 10.1038/ijo.2008.11. Epub 2008 Feb 19. PMID: 18283284; PMCID: PMC2877506.
32. Mulligan AA, Lentjes MAH, Luben RN, Wareham NJ, Khaw KT. Changes in waist circumference and risk of all-cause and CVD mortality: results from the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) cohort study. BMC Cardiovasc Disord. 2019 Oct 28;19(1):238. doi: 10.1186/s12872-019-1223-z. PMID: 31660867.
33. Abate N, Garg A, Peshock RM, Stray-Gundersen J, Grundy SM. Relationships of generalized and regional adiposity to insulin sensitivity in men. J Clin Invest. 1995 Jul;96(1):88-98. doi: 10.1172/JCI118083. PMID: 7615840.
34. Antonopoulos AS, Tousoulis D. The molecular mechanisms of obesity paradox. Cardiovasc Res. 2017 Jul 1;113(9):1074-1086. doi: 10.1093/cvr/cvx106. PMID: 28549096.sThompson D, Karpe F, Lafontan M, Frayn K. Physical activity and exercise in the regulation of human adipose tissue physiology. Physiol Rev. 2012 Jan;92(1):157-91. doi: 10.1152/physrev.00012.2011. PMID: 2229865Grundy SM, Neeland IJ, Turer AT, Vega GL. Waist circumference as measure of abdominal fat compartments. J Obes. 2013;2013:454285. doi: 10.1155/2013/454285.PMID: 23762536.
35. Sommer I, Teufer B, Szelag M, Nussbaumer-Streit B, Titscher V, Klerings I, Gartlehner G. The performance of anthropometric tools to determine obesity: a systematic review and meta-analysis. Sci Rep. 2020 Jul 29;10(1):12699. doi: 10.1038/s41598-020-69498-7. PMID: 32728050.
36. Zhu S, Heshka S, Wang Z, Shen W, Allison DB, Ross R, Heymsfield SB. Combination of BMI and Waist Circumference for Identifying Cardiovascular Risk Factors in Whites. Obes Res. 2004 Apr;12(4):633-45. PMID: 15090631.
37. Thomas DM, Bredlau C, Bosy-Westphal A, Mueller M, Shen W, Gallagher D, Maeda Y, McDougall A, Peterson CM, Ravussin E, Heymsfield SB. Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model. Obesity (Silver Spring). 2013 Nov;21(11):2264-71. doi: 10.1002/oby.20408. Epub 2013 Jun 11. PMID: 23519954; PMCID: PMC3692604.
38. Zhang X, Ma N, Lin Q, et al. Body Roundness Index and All-Cause Mortality Among US Adults. JAMA Netw Open. 2024;7(6):e2415051. doi:10.1001/jamanetworkopen.2024.15051 Zhang X, Ma N, Lin Q, et al. Body Roundness Index and All-Cause Mortality Among US Adults. JAMA Netw Open. 2024;7(6):e2415051. doi:10.1001/jamanetworkopen.2024.15051 Rico-Martín S, Calderón-García JF, Sánchez-Rey P, Franco-Antonio C, Martínez Alvarez M, Sánchez Muñoz-Torrero JF. Effectiveness of body roundness index in predicting metabolic syndrome: A systematic review and meta-analysis. Obes Rev. 2020 Jul;21(7):e13023. doi: 10.1111/obr.13023. Epub 2020 Apr 8. PMID: 32267621.
39. Zhou D, Liu X, Huang Y, Feng Y. A nonlinear association between body roundness index and all-cause mortality and cardiovascular mortality in general population. Public Health Nutr. 2022 Nov;25(11):3008-3015. doi: 10.1017/S1368980022001768. Epub 2022 Aug 19. PMID: 35983642; PMCID: PMC9991644.
40. Cai X, Song S, Hu J, Zhu Q, Yang W, Hong J, Luo Q, Yao X, Li N. Body roundness index improves the predictive value of cardiovascular disease risk in hypertensive patients with obstructive sleep apnea: a cohort study. Clin Exp Hypertens. 2023 Dec 31;45(1):2259132. doi: 10.1080/10641963.2023.2259132. Epub 2023 Oct 8. PMID: 37805984
41. Wu L, Pu H, Zhang M, Hu H, Wan Q. Non-linear relationship between the body roundness index and incident type 2diabetes in Japan: a secondary retrospective analysis. J Transl Med. 2022 Mar 7;20(1):110. doi: 10.1186/s12967-022-03321-x. PMID: 35255926; PMCID: PMC8900386.
42. Zhang Y, Gao W, Ren R, Liu Y, Li B, Wang A, Tang X, Yan L, Luo Z, Qin G, Chen L, Wan Q, Gao Z, Wang W, Ning G, Mu Y.Body roundness index is related to the low estimated glomerular filtration rate in Chinese population: A cross-sectional study. Front Endocrinol (Lausanne). 2023 Mar 28;14:1148662. doi: 10.3389/fendo.2023.1148662. PMID: 37056676; PMCID: PMC10086436.
43. Yang, Y., Shi, X., Wang, X., Huang, S., Xu, J., Xin, C., Li, Z., Wang, Y., Ye, Y., Liu, S., Zhang, W., Lv, M., & Tang, X. (2025). Prognostic effect of body roundness index on all-cause mortality among US older adults. Scientific reports, 15(1), 17843. https://doi.org/10.1038/s41598-025-02598-4
44. Grundy, S. M., Neeland, I. J., Turer, A. T., & Vega, G. L. (2013). Waist circumference as measure of abdominal fat compartments. Journal of obesity, 2013, 454285. https://doi.org/10.1155/2013/454285 
45. Rimm EB, Stampfer MJ, Colditz GA, Chute CG, Litin LB, Willett WC. Validity of self-reported waist and hip circumferences in men and women. Epidemiology. 1990 Nov;1(6):466-73. doi: 10.1097/00001648-199011000-00009. PMID: 2090285.
46. Gao, W., Jin, L., Li, D. et al. The association between the body roundness index and the risk of colorectal cancer: a cross-sectional study. Lipids Health Dis 22, 53 (2023). https://doi.org/10.1186/s12944-023-01814-2

The post A New Number for Health: Should Body Roundness Index Replace BMI? appeared first on Barbell Medicine.

Checking blood pressure at home can be an excellent option, but requires careful technique with the appropriate equipment.

How to Check Your Blood Pressure At Home

The most accurate way to measure your blood pressure at home involves using a validated automatic blood pressure machine under the correct conditions. A list of validated blood pressure devices is available at ValidateBP.org.

First, the blood pressure cuff should be appropriately sized for your arms — a cuff that is too small will give falsely high blood pressure readings, while a cuff that is too large will give falsely low readings. We can correlate the circumference of the upper arm (for example, using a measuring tape around the upper arm) to an appropriate cuff size, as shown in the table below. AHA Fortunately, most devices are now sold with variable-size cuffs that will fit most arms from the “small adult” to “large adult” range.

Steps to Measure Your Blood Pressure:

When ready to measure your blood pressure, follow these steps. For a graphical illustration, see here.

1. Ensure you have a quiet room, a chair with back support, and a table.
2. Place the blood pressure cuff on your arm, lining up the artery indicator line on the cuff over the inner part of your upper arm. When using an upper-arm blood pressure device, the lower end of the cuff should sit about 2–3 centimeters (about an inch) above your elbow crease. 
3. Rest your arm on an elevated surface, like a table, a box, or a few pillows, so that your arm is at the height of your heart. Ensure your arm is relaxed and your palm is facing upwards.
4. Once everything is properly positioned, sit upright with your back supported, legs uncrossed, and feet flat on the floor. Sit quietly for five minutes while remaining relaxed in this position before taking the first measurement. 
5. Start the machine to have it take your blood pressure while staying relaxed. Repeat the measurement a second time for more reliable results.

How Often Should You Check Your Blood Pressure?

For generally healthy adults without a diagnosis of high blood pressure, resting blood pressure should be checked at least once per year. USPSTF 2021.

If an adult is undergoing evaluation for high blood pressure, they can have blood pressure checked in the physician’s office, but should also have out-of-office measurements performed for confirmation. When evaluating people for high blood pressure using home measurements we recommend a minimum of three days of measurements, two in the morning and two in the evening on each day. Bello 2018

Even if the resting blood pressure measurements are high, this can be addressed gradually over time with a primary care doctor if no other symptoms are present. Emergency care is rarely needed, only in situations where symptoms like chest pain, shortness of breath, vision changes, confusion, or stroke-like symptoms are present, but otherwise can safely be managed in the primary care setting.

Conditions like white coat hypertension and masked hypertension require blood pressure monitoring outside of the doctor’s office. The preferred method is known as “24-hour ambulatory blood pressure monitoring”, where a special blood pressure monitor is worn continuously for 24 hours and a series of measurements are taken automatically as you go about your day. However, properly calibrated home blood pressure machines can be used if 24-hour monitors are not available. Carefully measuring blood pressure as outlined above, twice in the morning and twice in the evening for at least 3 days, can provide useful information to help your doctor make recommendations.

What Is A Good/Healthy Blood Pressure Reading?

In general, a healthy resting blood pressure for most adults falls below 120/80 mmHg.

However, interpreting blood pressure values can be challenging. Sometimes the measurements can be falsely high or low due to problems with cuff size or measurement technique. 

It can also be expected and even appropriate for people’s blood pressure to be transiently higher, for example during exercise or stressful situations. Other people live with resting blood pressures much lower than 120/80 mmHg. This can also be normal, especially if they feel well and have no symptoms like lightheadedness, dizziness, chest pain, passing out, or other concerning symptoms. What is most important is the person’s average, resting blood pressure over long periods of time.

For adults who already have a diagnosis of high blood pressure, current guidelines recommend targeting a blood pressure goal of less than 130/80 mmHg, and ideally below 120 mmHg when feasible. This is especially important for people at high risk of heart disease, stroke, and other complications. It is not always wise or feasible to target the lower numbers in all patients, depending on side effects of medicines, life expectancy, and other considerations.

When Should You See a Doctor?

In general, if your resting blood pressure is above the goal range without any symptoms like those mentioned above, you can work with your doctor to gradually improve it using lifestyle strategies and medications, as outlined in our Guide to High Blood Pressure.

If you are having significant symptoms like those mentioned above along with a significantly high or low blood pressure, it is wise to see a doctor more quickly.

The post How To Measure Your Blood Pressure Correctly appeared first on Barbell Medicine.

You’re sore, really sore. You notice it the most in your abs, but chalk it up to one of the workouts that included 60 glute-ham developer sit-ups and 15 toes to bar in this past weekend’s competition. “I’m probably just getting older,” you say, as you hobble to the bathroom to get ready for work. Then, something happens you can’t ignore: dark, cola-colored urine. 

You immediately call your doctor, who tells you to come in to be seen. The doctor finds that in addition to soreness and swelling in your muscles, especially your abdomen, you have a bunch of whacky labs. The most concerning lab abnormality is your creatine kinase, a marker of muscle damage, is over 100-times higher than it should be. Your doctor sends you to the emergency department where the diagnosis is made: exertional rhabdomyolysis.

Rhabdomyolysis is the state of extensive muscle damage that can lead to serious complications with organs like the kidney, heart, and more.  Causes of rhabdomyolysis range from exercise or exertion in this case, to drugs, car accidents, thermal stress, and more, that we’ll discuss in this article. We’ll also cover how rhabdomyolysis is diagnosed, its treatments, and how to return to activity afterwards. 

For completeness, the individual in this medical case was admitted to the hospital to receive fluids and be monitored. She did well, with both her labs and symptoms improving enough to be discharged home after four days. For more details on this case and exertional rhabdomyolysis, listen to our podcast here.

What is rhabdomyolysis?

Rhabdomyolysis is a medical condition involving the rapid breakdown of skeletal muscle tissue causing their intracellular contents to spill into the blood stream in relatively high quantities.¹ Most of the major medical complications of rhabdomyolysis are due to this mechanism. 

For example, myoglobin is an iron-containing protein normally contained within skeletal muscle cells. Its main job is delivering oxygen when the muscle tissue is active. If myoglobin ends up in the blood stream in high quantities from rhabdomyolysis, it can cause issues with kidney function. 

What are the symptoms of rhabdomyolysis?

Clinically, rhabdomyolysis can involve muscle pain and weakness due to the breakdown of muscle tissue. The release of cell contents can cause a variety of complications, the most apparent of which is dark or “coca cola-colored” urine from the presence of myoglobin. However, only a minority (<10%) of cases have all three of these features, with over half of patients not reporting muscle pain or weakness despite having rhabdomyolysis. ² 

Muscle pain commonly affects the thighs, shoulders, lower back, and calves, but can occur anywhere, including the abdominal muscles after too many sit-ups on the glute-ham developer like the woman in our introduction.³  

Other muscle symptoms include stiffness and cramping. Muscle weakness may be present depending upon the severity of muscle injury and occurs in the same muscle groups affected by pain or swelling, with the proximal legs most frequently involved. Muscle swelling can occur, and can be further exacerbated by the administration of intravenous fluids in the hospital setting.

What’s the difference between delayed onset muscle soreness (DOMS) and rhabdomyolysis?

Delayed Onset Muscle Soreness (DOMS) is discomfort in the active muscles following physical exertion that increases in intensity over the initial 24 hours, peaking at around 24- to 72-hours post-workout and then gradually subsiding. The severity of DOMS can range from mild to severe and is often associated with muscle stiffness, tenderness, and increases in creatine kinase (CK). 

While similar to exertional rhabdomyolysis, DOMS does not typically result in CK elevations as high as what is seen in rhabdomyolysis, where 5-times the upper limit of normal is commonly used cut-off for rhabdomyolysis diagnosis. In contrast, CK levels are not reliably correlated to the presence or severity of DOMs. 

However, there is a condition dubbed “HyperCKemia”, defined by elevated blood CK levels greater than 5 times the upper limit of normal, myoglobin in the urine, but no significant muscle symptoms or organ damage like kidney injury.^{4, 5}  Both military personnel and division I American football players have been shown to occasionally have CK levels greater than 5 times the upper limit of normal, with presence of myoglobin in the urine, but no other signs or symptoms of rhabdomyolysis.⁶ Elevated CK levels represent a challenging situation for a health care professional. While some individuals will have a completely benign increase in CK levels after exercise, others may have an underlying issue that would benefit from further testing and work-up.⁷

While both DOMs and rhabdomyolysis are both the result of muscle damage, rhabdomyolysis is the result of far more extensive muscle breakdown than DOMs.

What causes Rhabdomyolysis?

Rhabdomyolysis has a variety of potential causes, all of which ultimately lead to rapid muscle breakdown. 

Direct causes of rhabdomyolysis are mostly related to trauma and include:

• Crush syndrome
• Surgery with prolonged immobilization or vascular occlusion
• Physical restraints 
• Compression of blood vessels via tourniquets 
• Burn or electrical injuries
• Prolonged, strenuous, physical exertion- particularly to unaccustomed events (e.g. the case of exertional rhabdomyolysis in the introduction)

Other medical conditions or environmental conditions may cause rhabdomyolysis indirectly, such as: 

• Inherited disorders of muscle structure (e.g. Duchenne’s muscular dystrophy)
• Metabolic disorders that impair energy production and utilization (e.g. McArdle disease)
• Hyperkinetic states (e.g. seizure)
• Medications, supplements, or toxins (especially stimulants) ⁸ 
• Certain infections (influenza, HIV, and even COVID) ⁹
• Medical conditions (e.g. sickle cell anemia)
• Thermal stress (e.g. heat illness or frostbite) ¹⁰ 

Rhabdomyolysis can also have a combination of multiple contributing causes. For example, dehydration, environmental heat/humidity exposure, or any underlying muscle disease (known as “myopathy”) may lead to rhabdomyolysis with less intense or prolonged exercise, compared with the same amount of exercise in the absence of these risk factors. Sickle cell trait and sickle cell disease are other examples of conditions that can increase the risk of rhabdomyolysis and a life-threatening syndrome known as Exercise Collapse Associated with Sickle Cell Trait or “ECAST”. 

Do Statins Cause Rhabdomyolysis?

Statins are commonly used medications to lower blood cholesterol levels and the risk of heart disease complications. These compounds were discovered in the 1970s and underwent clinical studies before approval for use in 1987. Since then, simvastatin, pravastatin, atorvastatin, rosuvastatin, and several others have become available for clinical use. One common concern with their use is the risk of muscle pain and, in extreme cases, rhabdomyolysis.  

Regarding the risk of rhabdomyolysis in statin-users, it is very low. A recent review of over 1 million statin users found only 102 individuals (0.009%) had statin-induced rhabdomyolysis.⁷ The biggest risk factor for statin-induced rhabdomyolysis appears to be interactions with other drugs, which is likely responsible for nearly 50% of cases. ¹¹ 

Next, the incidence of muscle pain (i.e., myalgias) is often misattributed to statins. In a blinded, randomized-controlled trial among patients who were considered to be “statin intolerant” due to a history of muscle pain from statins, muscle pain was reported in 25% of the all subjects, regardless of whether they were receiving the statin or placebo. This is interesting because all (or at least a higher percentage) of the subjects getting the statin should have reported muscle pain if truly statin intolerant, and none (or a lower percentage) of the folks getting the placebo should have experienced muscle pain. ¹² 

The misattribution of muscle pain to statin is important, as a large study of statin-users found that experiencing muscle pain is an important driver of statin discontinuation, statin switching, or other statin non-adherence. ¹³  So, what does The Science say? 

In terms of real risk, if we took 10,000 patients with a history of cardiovascular disease treated with statins for 5 years, we’d predict about 5 total cases of muscle damage. Conversely, in those same 10,000 patients with pre-existing cardiovascular disease we would prevent major vascular events in about 1,000 patients over those 5 years. ¹⁴ 

In studies comparing statins to placebo pills, when patients know which option they are taking, side effects are reported more frequently with statins. However, when they are unaware if they are taking a statin or placebo, these muscle-related side effects are reported at the exact same frequency. ^15,16 

This suggests most of the experienced muscle pain-related side effects are likely due to the nocebo effect, where patients with expectations of adverse effects are more likely to experience them, and helps to explain the differences between rates of “statin intolerance” due to muscle pain in the community (8-12%) compared to the rate observed in blinded, randomized-controlled trials (~5%).¹⁷ 

Overall, statin use does appear to represent a small increase in risk of experiencing muscle pain, muscle breakdown, and in some rare cases, rhabdomyolysis. For most individuals who have been prescribed statins over, the risk is outweighed by the potential benefits. Patients should discuss their concerns over the risks and benefits of statin use with their physician, not ChatGPT.

Rhabdomyolysis Pathophysiology

In general, rhabdomyolysis results from a specific “insult” to the muscle that ultimately leads to large amounts of muscle damage and subsequent breakdown. After the insult to the muscle, the ion channels that normally maintain normal electrolyte levels within the muscle, i.e. low levels of sodium and calcium, and high levels of potassium, no longer work appropriately.  

As a result, there is a massive shift of sodium and calcium into the muscle fiber, thereby causing further damage, swelling, and breakdown of the muscle- perpetuating a sort of self-sustaining muscle breakdown cycle and muscle fiber death or necrosis.

With extensive muscle breakdown, the contents that were previously inside the muscle are released into the bloodstream, which ultimately leads to complications of rhabdomyolysis. 

What are the complications of Rhabdomyolysis?

Severe muscle injury during rhabdomyolysis causes problems with normal function of ion channels that maintain electrolyte levels, leading to a cycle of cell swelling, damage, and further breakdown. The contents of muscle cells, including cell proteins, enzymes, and electrolytes are released and leak out into the bloodstream. 

Myoglobin

For example, myoglobin is a protein contained within muscle, responsible for delivering oxygen to working muscle. It is not normally found in the blood in any meaningful concentration. However, when it is inappropriately released into the blood in higher quantities during rhabdomyolysis, its small size allows it to filter through the kidney and get excreted in the urine. Depending on the levels, this can lead to visibly dark urine, and it can also be detected on urine testing.
When levels of myoglobin release and filtration are extremely high, these tiny proteins can accumulate in the tubules of the kidney, leading to blockage. This can cause varying degrees of kidney injury, ranging from mild kidney injury that recovers with time and fluid support, to complete kidney failure requiring dialysis.

Creatine Kinase

Creatine kinase (CK), sometimes known as creatine phosphokinase (CPK), is an enzyme normally located within cells that plays an important role in energy production. It is also released into the bloodstream from damaged muscle. While normal blood levels of CK are 26-140 units/liter (U/L), in rhabdomyolysis, blood CK levels are usually at least five times the upper limit of normal, and can range from approximately 1500 to well over 100,000 U/L.¹⁸
In contrast to myoglobin, creatine kinase itself is not harmful or injurious when released into the bloodstream. It is a useful biomarker of the degree of muscle injury, and together with other variables can help estimate the risk of complications from rhabdomyolysis, including kidney problems. However, the interpretation of CK levels can be complex. Release of creatine kinase into the blood can occur from any degree of physical exertion, so just because a blood level of CK is elevated does not automatically diagnose rhabdomyolysis.

Electrolytes

 Other components within the muscle such as potassium, phosphate, and calcium are also released, causing electrolyte abnormalities, which can lead to a host of worrisome problems. For example, Cardiac dysrhythmias and risk of cardiac arrest may result from hyperkalemia and hypocalcemia associated with rhabdomyolysis. 

Increased pressure within the muscular compartments affected by rhabdomyolysis can also impair the delivery of oxygenated blood flow, which is a surgical emergency known as compartment syndrome.¹⁹ 

How is Rhabdomyolysis Diagnosed?

The diagnosis of rhabdomyolysis involves a comprehensive clinical assessment, including a detailed history, physical examination, and supporting lab data. This assessment is also necessary in order to determine the risk of severe complications, which will guide the immediate management plan in each case.

Laboratory assessment involves measurement of levels of the contents of muscle cells that get released into the blood during rhabdomyolysis, including creatine kinase, electrolytes like potassium, and an assessment of kidney function. Urine testing can help identify myoglobin being filtered through the kidneys. Other testing will depend on the clinical situation, and the suspicion for another simultaneous issue, complication, or undiagnosed disorder that predisposes the person to develop rhabdomyolysis.

The CK upper limit of normal is defined by each laboratory, and both baseline and physiologic post-exertion CK levels are quite variable, even among individuals based on age, gender, muscle mass, ethnicity, type of activity, as well as medical history.

The serum CK begins to rise within 2 to 12 hours following the onset of muscle injury and reaches its maximum within 24 to 72 hours. A decline is usually seen within three to five days of cessation of muscle injury. CK has a serum half-life of approximately 1.5 days and declines at a relatively constant rate of approximately 40 to 50% of the previous day’s value. In patients whose CK does not decline as expected, ongoing muscle injury, an underlying muscle disease, or the development of compartment syndrome may be present.

The widely accepted diagnostic threshold of CK greater than 5 times the upper limit of normal ULN is extremely sensitive but poorly specific. This means that if the person’s CK level is below this threshold, we can be reasonably confident that they do not have rhabdomyolysis; however, we still can’t confidently diagnose rhabdomyolysis if it is above this threshold alone. Multiple studies have shown that athletes regularly reach a CK greater than 5 times the upper limit of normal in the context of their routine activity. ²⁰

Overall, exertional rhabdomyolysis is a clinical diagnosis that relies on careful interpretation of the patient’s history, symptoms, presentation, and laboratory findings. 

How is Rhabdomyolysis Treated?

The treatment of rhabdomyolysis from all causes is geared towards supporting normal organ function (e.g. the kidneys) and monitoring for potential complications.  Patients with high risk features such as severe symptoms, very high CK levels, large electrolyte abnormalities, underlying medical conditions and more are usually admitted to the hospital for rhabdomyolysis. In some cases of exertional rhabdomyolysis (e.g. from exercise) can be safely and effectively treated at home, which is both cost-effective and generally preferred by patients. Determining which patient requires hospital admission is a critical decision point and should be individualized.

Supportive care generally starts with administering fluids. Hospitalized patients are typically treated with moderate to high rates of intravenous fluids, with monitoring for complications in their electrolytes, kidney function and urine output, and physical examination. 

Severe abnormalities in electrolyte levels can trigger dangerous heart rhythms, severe kidney impairment can require temporary dialysis, and the combination of muscle injury and high volumes of fluid administration can increase the risk of developing compartment syndrome in the limbs. In addition, medical evaluation for the underlying cause of rhabdomyolysis may take place during admission if the cause was not apparent on initial presentation. 

There are no established “safe” discharge criteria with regard to specific lab values. For example, two retrospective reviews of 30 and 41 cases found discharge CK values ranging from 1,410 to 94,665 U/L and 10 to 61,617 U/L, respectively. ²¹ Neither report found any evidence for higher CK levels being associated with higher rates of readmission. Other factors important for safe discharge are normal or improving kidney function, and reliable patient follow-up.

How to return to activity after rhabdomyolysis?

Return to exercise or sport after rhabdomyolysis varies significantly based on the individual. There are four major considerations relating to return to activity after a bout of rhabdomyolysis:

1. Resolution of syndrome
2. Adequate explanation for episode
3. Plan to identify & address risk factors to avoid recurrence
4. Plan for graded return to activity

The first requirement for return to activity is a resolution of the rhabdomyolysis syndrome. This means that symptoms like muscle pain and swelling have returned to normal, and the person is urinating normally.

In the context of sport, an athlete who does not clinically recover, as evidenced by a resolution of their symptoms and a normal physical exam, within 1 week of rest is at higher risk for recurrence upon return to training or competition. An athlete with no clinical symptoms (e.g. weakness, swelling, pain, soreness), a CK level less than 5 times the upper limit of normal, and normal urine testing can be considered for return to sport.

The second requirement is that the initial episode should have an adequate explanation. For example, a person who develops exertional rhabdomyolysis after a bout of novel physical activity that was clearly too high in volume and/or intensity for them, has an adequate explanation for their case. 

In contrast, a person who develops rhabdomyolysis after a disproportionately low workload, such as after doing some light house work, does not have a sufficient explanation for their syndrome, and should undergo additional evaluation. This scenario raises concern for an undiagnosed problem or risk factor that predisposes them to developing rhabdomyolysis even at low or moderate levels of exertion. This evaluation should include more detailed personal and family history for prior episodes of rhabdomyolysis or other muscle disorders, as well as consideration of other risk factors such as medications/toxins, metabolic or hormone disorders, autoimmune disorders, and sickle cell trait or disease, among others.

The third requirement is that risk factors for the initial bout be identified and develop a plan to address them. A person who develops exertional rhabdomyolysis from a workout that was far too high in volume or intensity compared with their level of fitness, should have a plan to more gradually build up their fitness to tolerate that level of workload, if it is their goal to be able to do so again. 

If the person was working out in a very hot environment, or was not drinking sufficient water or other fluids during/around the workout, they should have a plan to address these risks upon return to exercise. This could include a plan for improved ventilation in the workout space, working out at a cooler time of day, and ensuring constant access to sufficient fluid hydration around and during the workout. 

Finally, the fourth requirement should be an individualized plan for a graded return to activity. The target level of activity may be to reach the current physical activity guidelines, or the person may have higher targets in the context of dedicated training or competitive sport.

We view this period as a “rehabilitation” phase, much like when returning from any other acute injury, and design the training plan with attention to the person’s current (post-rhabdomyolysis) level of fitness and tolerance for activity, their longer-term goals, their preferences for activity, and any other co-existing limitations. For many, a “beginner” approach to training may be appropriate in the initial return to activity, even if they were previously well-trained athletes.

Sample plan to exercise after exertional rhabdomyolysis

We currently lack strong evidenced-based guidelines on return to unrestricted activity, but some clinician scientists have recommended a four phase approach.

Phase 1

Phase 1 lasts a minimum of 72 hours after the bout of rhabdomyolysis, and focuses on significant activity modification and early follow-up. Guidance involves rest or light indoor activity, getting 7 to 8 hours of sleep per night, drinking plenty of fluids, and increasing dietary sodium intake (e.g., cottage cheese, peanuts/nuts, pretzels, soy sauce, canned beans). Moderate- or high-intensity activity, including resistance exercise, should be avoided until the next phase.

Phase 2

Phase 2 typically occurs 3-7 days after diagnosis, though this can vary. At this time, CK levels are below 5 x the upper limit of normal, urinalysis is normal, and the individual remains symptom-free, then phase 2 may begin. Note that because muscle pain serves as a clinical guide for progression through the phases, pain relievers (acetaminophen and NSAIDs) should be avoided in order to not mask pain.

Phase 2 introduces light activities, e.g. low-intensity recreational activities like walking, lightweight, low-volume resistance training, such as bodyweight exercise or loads below 20-25% of 1-repetition maximum (1RM). If the person remains symptom-free after 1 week, they may progress to phase 3. In contrast, if symptoms return, they should remain in phase 2 with weekly follow-ups until activities can be completed symptom-free.

Phase 3

Phase 3 is reached when the individual can perform activities symptom free. At this point, the individual can now increase the intensity of exercise, though the volume should still remain relatively low compared to what was being done prior to the bout of exertional rhabdomyolysis.. Resistance training intensities can increase to 50% to 75% of 1RM, agility drills at 70% to 80% of maximal effort, and running can begin at 50% to 75% of normal time and distance.

Phase 4

Phase 4 returns the athlete to full physical training with follow up as needed. Exercise volume should be gradually progressed over the course of several weeks in order to avoid another sudden increase in workload. Additionally, recall that if there were other predisposing risk factors identified during the evaluation, such as a hot/humid environment, inadequate hydration, or other underlying medical problems, these must be addressed in order to minimize the risk of recurrent rhabdomyolysis in the future.

Take-Home

Rhabdomyolysis is a medical condition involving the rapid breakdown of skeletal muscle, leading to the release of contents of muscle cells. It can present with muscle pain, weakness, swelling, and dark urine due to this breakdown of muscle tissue. The release of cell contents can cause a variety of complications, the most feared of which is kidney failure.

 Rhabdomyolysis is most often caused by intense, prolonged physical exertion that exceeds the person’s level of fitness. Certain variables can increase the risk of rhabdomyolysis even in fit individuals, such as dehydration, environmental heat and humidity, or the use of stimulants. Other underlying medical conditions can cause rhabdomyolysis in the absence of any significant physical exertion, or may predispose people to develop rhabdomyolysis with much lower amounts of exertion than would be expected.

The diagnosis of rhabdomyolysis involves a detailed history, physical examination, and lab testing, most notably measurement of blood Creatine Kinase (CK) levels, urinalysis, and assessment of electrolytes and kidney function. This assessment is necessary to determine the risk of severe complications, which will guide the immediate management plan in each case.

Interpretation of lab creatine kinase measurements is complex. All muscular exertion can increase CK levels to some degree; an arbitrary cutoff of elevations in CK to greater than 5 times the upper limit of normal is often used in the diagnosis of rhabdomyolysis. However, this criterion alone is insufficient for the diagnosis; many physically active individuals may routinely exceed this cutoff with no other signs, symptoms, or clinical evidence of rhabdomyolysis syndrome. Creatine kinase is a non-toxic biomarker of muscle injury, in contrast to myoglobin, which is the primary cause of rhabdomyolysis-induced kidney injury.

 Management of rhabdomyolysis can range from outpatient/home setting with activity modification and maintaining adequate fluid intake, to hospitalization with close laboratory monitoring for complications requiring intensive care or dialysis.

Return to activity like exercise after rhabdomyolysis requires attention to several details, including resolution of the syndrome, an adequate causal explanation for the episode, a plan to address risk factors to avoid recurrence, and an individualized plan for a grade return to activity.

The post Rhabdomyolysis: Causes, Treatments, and Return to Sport appeared first on Barbell Medicine.

For some, the idea of pursuing a career in fitness is so appealing that they’ll actually take action.

I’m one of those people. A little over five years ago I left a comfortable accounting career to open my own gym and become a full-time gym owner and coach.

Changing careers is a big decision requiring a lot of thought and consideration. There are certain questions I wish I had been asked before making the switch; had someone asked me these tough questions, I would have felt better prepared early on.

In this article, I’m going to present a series of questions to consider before deciding whether the fitness industry is right for you. It’s important to be honest with yourself when answering these questions. A career as a fitness professional, whether full- or part-time, can be very demanding. You will be in a position where your actions will have a direct impact on the health and wellbeing of another person. This is a big responsibility and should not be taken lightly.

If you’re planning on changing careers to become a fitness professional, then you’ll have to prepare yourself for the possibility that on paper, the switch initially won’t make sense. But if you’re like me, your passion will push you to take the risk anyway. If that’s the case, at least you’ll be well-informed!

Note: For whatever reason, most veteran coaches abhor the term “personal trainer”, even if the bulk of their work is 1-on-1 with clients. We’ll use the term “coach” for the rest of the article, save for places we need to say “personal trainer” for the broader audience, but just know that for all intents and purposes, it’s just another name for a personal trainer. 

Who Makes A Good Personal Trainer/Coach?

The best coaches I’ve worked with were passionate about TEACHING.

I’ve hired and trained seven different personal trainers since opening my gym. Of those seven, four were very passionate about fitness. If I’ve learned anything from those four hires it’s this: people who say they are “passionate about fitness” often make for poor coaches.

Don’t get me wrong — these people were fit, loved training, and they loved being in the gym. So, naturally, they thought that making “fitness” their job would be perfect. This turned out to be wrong. They all quit in less than six months and pivoted to entirely different industries.

The issue with people who are “passionate about fitness” is that they are passionate about THEIR OWN fitness. And there is nothing wrong with that — but it’s important to understand that being a coach isn’t about your fitness; it’s about the client’s progress, satisfaction, and happiness.

Based on my hiring experience, here are the questions you should ask yourself:

1. Have I always considered a career as a teacher or instructor to be right for me? 
2. Are there instances in my life when I volunteered to teach or mentor others? 
3. How do I feel when I help an older person with technology? 

That last one may sound like a joke, but is actually relevant. The answer to each of these questions will tell you something about yourself. 

If you’ve never been keen on the idea of dedicating your life to teaching, training new employees, or tutoring others, you probably won’t enjoy coaching. Teaching, mentoring, tutoring, and educating are all fundamental aspects of coaching. 

If you can’t think of any time in your life where you volunteered to help others learn for no reason other than you just wanted to, you probably won’t like being a coach. Much like school teachers, you typically don’t get into coaching just for the money. You have to be the kind of person who gains true fulfillment from teaching others how to do things, and then seeing them progress towards mastery. It can be a slow process that requires lots of patience, with the only payoff being that someone else got better.

If you find that your patience runs thin anytime you’re asked to help elderly family members learn how to use their smartphone, you probably won’t enjoy teaching someone to lift weights. 

You’ll be amazed at how many people have zero body awareness or control. You’ll ask them to widen their stance, and they’ll bring their feet closer together instead. Tell them to lift their chest, and they’ll round their back instead. You’ll have clients performing triceps extensions and tell you they feel the exercise in their calves (true story!) You’ll work with a client for six months and they still won’t know the name of a single exercise, and require a demonstration and explanation every time. If that sounds frustrating to you… it certainly can be.

That’s why you need a high level of patience and empathy when coaching. You need to understand where each person is coming from, what each person deals with on a daily basis, and accept that exercise might simply be a chore for them. You need to accept and be proud that they acknowledge the importance of exercise and are investing in themselves by hiring you and showing up.

It’s the same empathy you need for the elderly family member who’s asking how to open Facebook on their smartphone. They are asking because they want to connect with friends and family. They are asking for help because the end result is important to them, and they feel as if they can’t do it alone.

Be honest with yourself regarding these questions. Changing careers is a huge decision, and if teaching others doesn’t give you a sense of fulfillment, and empathy towards people who are struggling to learn doesn’t come easily, then a coaching career may not be the right fit for you. 

How Much Do Personal Trainers/Coaches Work?

Full-time coaches, who are self-employed, can expect to work an average of 60 to 80 hours a week. This fact is something I didn’t fully appreciate when I became a full-time coach. 

Before I became a full-time coach, I was a Chief Financial Officer for a chain of restaurants. I was working about 40 hours a week in an office, and spending about 20 of those hours making memes. I had a salary of $90,000 per year before bonuses. I had weekends and holidays off, and could take up to 4 weeks of paid vacation every year. 

When we talk about work/life balance … that was it. 

So, imagine how overwhelmed I was when I made the switch to being a self-employed coach. I went from a cushy 9-5 to working 80-100 hours a week. No weekends. No days off. No vacations. Earning about $15,000 per year to start.

I definitely wasn’t ready for the number of hard hours I would be working, level of stress I would endure, and the constant grind to survive. But I had put my entire life savings into opening my gym. I had to keep going. I had no other option.

If I could go back, I would have asked myself this question:

“Are you willing to work as a Personal Trainer for 20-40 hours per week in ADDITION to your current full-time job?”

If the answer is “I can’t see myself working that much…” then you’re not ready to be a full-time coach. 

How Much Do Personal Trainers/Coaches Make?

According to the most recent data from the U.S. Bureau of Labor and Statistics, the median annual salary for Exercise Trainers & Group Fitness Instructors is $40,510 with an average annual salary of $45,110.

Your income as a coach will be heavily influenced by a number of factors. Some relevant factors are: 

1. Average income of your area
2. Distance from residential neighbourhoods
3. Target demographic
4. Training Specialty  
5. Years of experience
6. Investment into marketing
7. & Investment into Personal Development

The question I’ll offer for consideration is this: would you be able to live the life you want making $40-$50K per year?  

This is important because struggling financially tends to lead to resentment towards clients, and ultimately burnout. I’ve known several coaches who opened their own gym and called it quits after 3 years because of the financial burden. 

They believed that they could simply build a studio, and clients would flock to them because of their expertise. These coaches didn’t realize that in order to be successful in the fitness industry you must be an entrepreneur first, and a coach second. 

With that in mind, many successful coaches who provide excellent services and have a good sense for business will make multiples more than the industry average. 

How-To Build A Business As A Personal Trainer/Coach?

The most successful coaches are the ones who understand that coaching is a service, and clients are customers. Being a Coach means you’re self-employed. So, when you’re not actively working with clients, you need to be actively looking for clients. It’s a lot of work with a very low return on the time invested, and a lot of people ignoring you or telling you no.

For every 100 potential clients, 20 might respond to you. 8 or 9 will agree to meet you, 6 will actually show up, and two or three will hire you.

That’s about 50 “no’s” for every one “yes”. This can feel very discouraging, and it’s difficult not to feel like you failed a bunch before “getting lucky.” That brings us to the final question:

How do you view failure?

This question deals more with entrepreneurship than being a coach. However, it is probably the most important question so far. It’s important because most coaches are essentially self-employed.

Being self-employed means you will experience failure and losing, often on a daily basis. You’ll be told “no,” over and over again. You’ll question your self-worth. You’ll feel like when people say no to your services, they are saying you personally have no value. 

Early on I took every “no” as a personal failure. My fixed mindset allowed all the “no’s” to wreak havoc on my self-confidence, as well as my mental and physical health. It’s taken a lot of work, but I’ve grown past that way of thinking.

Now I approach challenges with a more objective mindset. When things are going poorly, instead of complaining, I ask myself:

1. What worked before? 
2. What’s not working now? 
3. What was I doing before that I’m not doing now? 
4. What’s in my control? 
5. What can I do today?

Once those questions are answered, I get to work. I’ll work until I can say “okay, I’ve addressed all the things in my control. I can’t worry anymore, now I just have to wait.” 

You cannot define success purely in terms of how many people hire you, or how much money you are making. You have to view success as the act of putting in an honest effort instead of basing it on the outcomes.

What Certification Should I Pick To Be A Personal Trainer/Coach?

Most commercial gyms require that their coaches or personal trainers have a certification that is recognized by the National Commission for Certifying Agencies (NCCA), which is an accreditation body. Popular options include certifications from the National Academy of Sports Medicine (NASM), the American Council on Exercise (ACE), the National Strength and Conditioning Association (NSCA), the American College of Sports Medicine (ACSM), and the International Sports Sciences Association (ISSA).

I’ve interviewed dozens of personal trainers. I can tell you that none of these certifications prepared any of them for working with people. If you want to be the best coach you can be, then you must be willing to be coached. 

You’ll have to invest the time and money into hiring more experienced coaches, working with them, learning from them, and understanding what the role of a coach is. 

As I previously stated, the best coaches are passionate about teaching. So it’s very easy to have an experienced coach agree to mentor you. You’ll want to shadow them as they work with clients, learn about their methodology, and draw from their real world experiences. 

The question to consider isn’t “which certification should I get?” The question you should be asking yourself is: am I willing to be coached?

For a deeper discussion on certifications, mentors, and learning to coach, see the panel YouTube video we recorded on the topic here.

How-To Pick A Good Personal Trainer/Coach?

The best coaches have a combination of extensive education and experience. Markers of education include both certifications and degrees, whereas gauging a coach’s personal and professional experience is not quite as straightforward. To get the most out of the client-coach relationship, you’ll want someone who has worked with lots of people that are like you in order to feel confident about your decision. To simplify, when it comes to choosing a coach, the majority of clients want to answer yes to one simple question: Do they seem trustworthy?

Different people will assess trustworthiness based on different criteria. Some will base it off of client reviews, others will look at certifications, some will base it on appearance or personal accomplishments, others will decide based on how you speak, and still others will make the decision based entirely on instinct. But, at the end of the day, they simply want to trust you.

Trust is the foundation of any positive relationship, whether it be personal or professional. 

As Barbell Medicine coaches, we start the trust building process immediately. New clients can expect to have a virtual meeting with their coach within 24-48 hours after signing up for coaching services. From there clients can expect a custom training program that takes into account all the information shared during their initial call. We will then check-in and follow up with clients to ensure all questions about the program are answered, and that the clients are set up for a successful first week of training. We continue to cultivate trust by continually checking in and adjusting a client’s program to fit with their lifestyle, performance, and goals. 

Clients should look for coaches who have well thought out systems and procedures in place. This ensures that they are working with a professional who can deliver on the services promised. The best coaches have a combination of education and experience 

Take Home

Making the transition from Accountant to Coach has been the hardest thing I’ve ever done. But for me, it’s been worth it. I know it’s my calling because I love to teach and explain things. I’m genuinely happy when I see someone make small progress. It makes me feel good and fulfilled when my clients thank me for my patience.

I’m proud of how far I’ve come as an entrepreneur because of the long and grueling hours I spent early on.

Mostly, I’m grateful for the growth I’ve experienced as a person. The challenges of changing careers has made me a better husband, coach, friend, entrepreneur, and person.
And that’s where I’ll leave you. A few questions to contemplate, and to answer truthfully. I hope you found this article helpful, and if you would like to get some specific advice, feel free to email me: sal@barbellmedicine.com

The post How-To Become A (Good) Personal Trainer appeared first on Barbell Medicine.

For example, an exercise program that includes both lifting weights and conditioning improves the body composition. In individuals who are losing weight, more muscle mass is preserved and more body fat is lost when those folks also exercise. However, the same relationship is true in those who are maintaining their weight. These individuals will tend to gain muscle and lose more body fat than those who are not exercising.^1,2 

Exercise also seems to increase how full people feel after eating a meal, e.g. their satiety response. While many claim that exercise will cause someone to “work up an appetite”, experimental data suggests that people will “eat back” only a small proportion of the amount of Calories used during exercise.^3,4 This is one of the ways in which exercise helps prevent weight regain in individuals who have lost weight. ⁵ It’s also important to mention that exercise is beneficial to both health and performance regardless of whether someone loses weight or not.⁶

All else being equal, we’d expect that exercise would help individuals to lose more weight and body fat, while also building more muscle, strength, and endurance, as compared to not exercising. The bulk of the scientific evidence supports this idea, particularly when combined with the appropriate diet for the individual.^7,8 This is because, in short – working out needs to be paired with the correct nutrition for the desired results.

In this article, we’ll cover three of the most common reasons that people have issues with weight management when they start working out: eating too many Calories, short-term changes in water retention, and measurement error.

Reason #1: Eating Too Many Calories

The number one reason someone is either gaining weight or failing to lose weight – regardless of how much exercise they’re doing – is because they’re eating too many Calories. Barring short-term changes to fluid status (e.g. from dehydration) or measurement error, any change in an individual’s body weight (and mass) is a direct result of energy balance. 

Although this information is accurate, it’s important to note that changing dietary behavior can be extremely challenging. This is because eating practices are influenced by a variety of biological, psychological, social, and environmental factors – and much of this influence on appetite and related behaviors occurs outside of our conscious control. 

We think that pretty much everyone could benefit from eating a health-promoting dietary pattern and regularly participating in exercise. However, it is important to avoid focusing exclusively on body weight or composition as a reflection of health or success. People have different values, preferences, and goals and we should respect those when treating individuals. There are often a number of lifestyle changes that can offer benefits independent of any effect on body weight or body fat. 

Energy Balance

Energy balance represents one of the fundamental principles of human metabolism. This physiological mechanism measures the relationship between caloric intake—the energy we obtain from food and beverages—and caloric expenditure, which occurs through basic metabolic processes and physical activity. 

When caloric intake exceeds expenditure, the body stores this surplus energy, typically as adipose tissue. When intake and expenditure are equal, body weight remains stable. During periods when caloric expenditure surpasses intake, the body draws upon its energy reserves, resulting in weight loss. Understanding this metabolic equation is essential for managing body weight.

Total Daily Energy Expenditure (TDEE) is the total amount of Calories used (“burned”) per day. The three components of TDEE are; 1) resting energy expenditure (REE), 2) diet-induced energy expenditure (DEE), and 3) activity-induced energy expenditure (AEE), modeled by the equation:

TDEE = REE + DEE + AEE

The relative contributions to total daily energy expenditure from each of these components are approximately 60% for REE, 10% for DEE, and 30% for AEE.⁹  If you’re wondering what your total daily energy expenditure is, check out our free TDEE calculator. 

The effect of energy balance on  body weight change takes place over a long period of time, e.g., many weeks and months, not hours and days. There’s also greater than 5-fold variability in response to the same energy deficit or surplus between individuals, which is mostly attributed to genetics. ^10,11

To summarize, if someone is losing weight, they are in a negative energy balance or Calorie deficit. If someone is gaining weight, they are in a positive energy balance or Calorie surplus.   Achieving meaningful, sustainable weight change takes time spent in either an energy deficit or surplus, and results often vary significantly between individuals.

Managing Your Energy Balance

At first glance, maintaining or manipulating your energy balance may seem simple. For example, if you want to lose weight, it would seem there are three basic, fool-proof ways to achieve your goal: 

• Consume fewer Calories than you burn.
• Increase your activity levels to burn more Calories than you consume.
• Increase your resting metabolic rate. 

These strategies all generally work, but yet again, our physiology is less straightforward. 

Reducing Calorie Intake

For example, reducing energy intake to achieve a Calorie deficit will indeed produce weight loss. However, many individuals’ bodies will fight back by reducing the amount of Calories used for basic metabolic processes and activity, while also increasing hunger cues, and decreasing feelings of fullness. ^{12, 13, 14} 

The combination of “metabolic adaptation”, where an individual using less energy, with increases in appetite leads to an inability to sustain an energy deficit, which then results in weight regain.  Reducing hunger and increasing feelings of fullness to not only achieve, but also sustain an energy deficit is one of the ways GLP-1 Receptor Agonist (GLP-1 RAs) like semaglutide and tirzepaitide work. 

Overall, reducing energy intake via changes to the diet are necessary to achieve a Calorie deficit. In many individuals however, their bodies will make adhering to the diet extremely challenging. 

Increasing Activity To Burn More Calories

Increasing the amount of exercise performed in order to burn more Calories is another strategy used to achieve a Calorie deficit. With long-term exercise however, other components of energy expenditure tend to adapt and reduce energy utilization, thereby making the energy deficit created from more exercise less than predicted. This is still an area of active research and so, we’ll present both sides.

On the one hand, the constrained energy model suggests that humans and other animals share a set of evolved mechanisms to maintain total energy expenditure within a narrow range. When presented with higher activity levels that uses more energy, the body compensates by reducing energy expenditure elsewhere to keep daily expenditure in check.¹⁵

On the other hand, the additive energy model suggests that increased physical activity has its own energy or Calorie cost, and this energy is “added” to the total energy expenditure the individual had before undertaking an exercise program.

As of this writing, the answer is somewhere in the middle. With long-term exercise, there seems to be some reduction in energy expenditure from other elements of metabolism that overall “attenuates” the amount of “extra” Calories being burned during exercise, and results in only modest changes to total daily energy expenditure.^{16,17,18, 19, 20, 21, 22, 23} This is likely one of the main reasons why weight loss with exercise interventions produce less weight loss than predicted, especially when exercise is combined with dietary changes. 

Overall, increasing energy expenditure by doing more exercise is likely to produce less weight loss than changes to the diet of a similar magnitude Calorie-wise. In other words, reducing intake by 500-Calories is likely to produce more weight loss than increasing exercise-related energy expenditure by 500-Calories. Still, doing more exercise is generally advisable for most regardless of the direct impact on weight loss, as it has significant health and performance benefits. 

How-To Increase Metabolic Rate To Lose Weight

Increasing metabolic rate as a means to lose weight sounds good in theory, but is generally not possible without using potentially harmful drugs.  

Resting Metabolic Rate (RMR) is the amount of energy used to sustain basic life processes such as breathing, heart function, and other essential tissue functions while an individual is awake. It’s typically measured after a 2-4 hour fast with the individual lying down in a neutral temperature environment (not hot or cold/shivering) for a period of 24 hours.

The majority (~80%) of an individual’s RMR is determined by the amount of lean body mass, which includes muscle, vital organs, extracellular fluids, and bone. ²⁴ In general, higher amounts of lean body mass result in a higher RMR. About 20% of the variance in RMR cannot be explained by lean body mass, race, sex, age, measurement error, or environmental factors. This variance is primarily attributed to genetic differences.^{25, 26} 

Changes in body weight typically produce changes in both lean and fat mass. The proportional change in lean and fat mass varies among individuals and depends on many factors including level of energy intake, diet composition, baseline body fat level, activity level, genetics, health status, age, and more. All told, weight loss is estimated to result in a loss of approximately 75% fat mass and 25% lean tissue, though this varies significantly amongst individuals.²⁷

With weight loss, the reduction in active body tissue also reduces energy expenditure by about 19 and 4.5 Calories/kilogram/day for lean and fat mass, respectively. ²⁸ If an individual loses 10 kg consisting of 75% fat and 25% lean mass, we’d expect a reduction in RMR of approximately 81 Calories/day. RMR reductions beyond this level could represent adaptive thermogenesis due to changes in hormonal and other cellular signals that act to preserve energy balance. ²⁹ 

Building muscle while reducing body fat commonly occurs in untrained individuals and those with obesity. ^30,31 However, RMR  does not seem to change that much when swapping a pound of fat for a pound of muscle.  No, one pound of muscle does not weigh “more” than one pound of fat. Rather, the density of fat is ~ 0.92 kg/L and the density of muscle is 1.06 kg/L, ^32,33  So, we could say that 1 kilogram of fat will take up a bit more space than 1 kilogram of muscle.  

Semantics aside, it takes quite a long period of time to build a substantial amount of muscle, especially when someone isn’t trying to gain weight. In one study, a group of 18 elite rugby athletes trained for 14-weeks before their season started, which produced an average gain of 2.0 kg of lean body mass. There was no significant change in RMR. ³⁴ Gaining muscle mass is certainly a good goal to chase from exercise, but it’s probably not going to increase RMR to a point where it helps in active weight loss efforts. 

As mentioned at the beginning of this section, there are some drugs that can increase RMR. Perhaps the most infamous is 2,4 dinitrophenol, or DNP. 

DNP is a chemical originally used to make explosives in World War I, but it has also been used as a dye, wood preservative, herbicide, and even to develop photographs. DNP works by uncoupling oxidative phosphorylation, which is the process our mitochondria use to create energy as our body is breaking down carbohydrates and fats. Instead of creating adenosine triphosphate (ATP), which is what our body uses for energy, DNP creates heat instead. This produces a large elevation in RMR (and heat) that can lead to weight loss. In the 1930’s, DNP was used for weight loss before studies showed that the drug was very toxic, leading to many medical complications including death. A number of DNP toxicity cases pop up each year, predominantly in bodybuilders who have purchased the powder over the internet despite the known harms. Of note, data on DNP shows that weight loss is generally smaller when compared to the newer GLP-1 RA medications. 

Again, increasing resting metabolic rate in order to create a Calorie deficit is not generally a viable strategy for weight loss.

Reason #2: Increased Water Retention

Short-term changes in body weight are primarily related to changes in total body water, not actual changes in fat or muscle mass. 

Humans are about 60% water by mass, though this ranges between 45 to 75% amongst individuals primarily due to different body compositions. Fat-free mass is typically between 70 to 80% water, while fat mass is only 10%. 

Changes in hydration are broken up into three main categories:

• Euhydration: This is when your body’s water levels are just right, requiring minimal adjustment by physiological mechanisms. The body tends to function most efficiently here and is considered to be the normal baseline. 
• Hypohydration: This is when total body water is decreased below baseline. It can vary in severity based on how low total body water is. People here have lost body mass via water.
• Hyperhydration: This is when total body water is above baseline. People here have gained body mass via water. 

Dehydration and hypohydration are often used interchangeably, but they are not really the same things. Dehydration is the process of losing body water, e.g. sweating during exercise, whereas hypohydration describes total body water status. 

While total body water is maintained within a relatively narrow range, small changes in hydration status can produce significant changes in body weight.  In a 70kg human, a 2% change in total body water range represents a predicted weight change of nearly two pounds. Experimental data shows that some individuals, particularly women, experience even greater fluctuations in total body water and body weight. ³⁵ 

The Effects of Exercise on Hydration

As you exercise, your muscles generate heat, which moves the blood to your core. This heat needs to be passed on through your skin to the environment. The small blood vessels in your skin help transmit this heat, which is when sweating occurs.

When all that heat is generated and transferred through your skin, you’ll need to cool down. Thankfully, your body knows how to do that. We sweat because the capillaries in our skin send the heat from our skin out to the environment. The vaporization of sweat accounts for ~80% of heat loss in hot, dry conditions. Therefore, our bodies produce sweat to cool us off when we are feeling the heat. 

A certain amount of water leaves our bodies to produce sweat. Therefore, if we lose more water through sweating than we consume, dehydration occurs, which may have a detrimental effect on both the heat transfer from the muscles and the whole process of sweating. For example, hypohydration of ~ 2% or more decreases the rate in which you sweat, the onset of sweating, and in many cases, subsequent performance. ^36,37 

In response to regular exercise, the body tends to retain more water to be better prepared for future bouts of exercise. This is especially true in hot, humid environments that promote a higher sweat rate in most individuals. 

Overall, changes in body water are common and can result in significant, short-term changes to body weight that are not associated with changes to the amount of fat or muscle someone has.

Recommendations for Hydration Before, During, and After Exercise

Maintaining an appropriate level of hydration is important for both performance and safety. ³⁸ To establish a reference for the euhydrated state in an individual, measure body weight first thing in the morning, after going to the bathroom, but before consuming any food or drinks for three days. The average weight calculated after collecting 3-day data is an individual’s reference rate for their euhydrated body mass. 

Once an individual’s euhydrated body mass is identified, our recommendations are as follows:

• Aim to start a workout within 1% of euhydrated weight.
• During a workout, aim to avoid losing more than 2% from euhydrated weight.
• After a workout, no specific hydration protocols are necessary for most people. Eating and drinking normally will be sufficient. 
• For those working out multiple times a day with limited recovery time,  aim to consume ~1.5L of water for each kilogram of body weight loss during exercise at a rate of ~0.4 to 1.5 liters per hour. The correct rate can vary significantly amongst individuals. 

To practically apply the recommendations above, an individual would need to establish their euhydrated reference weight, as well as weigh themselves before and after a workout in order to assess hydration status and make the appropriate changes. 

Reason #3: Measurement Error

Weight is accurately and precisely assessed with a scale, meaning there’s little reason to believe the scale is wrong. However, this doesn’t mean we can feel confident about a single weight.

Normal Fluctuations in Weight

In most humans, there is substantial variation in day-to-day weight due to changes in dietary practices, physical activity, and the body’s subsequent response. For example, a weekly rhythm in body weight has been observed, with individuals typically weighing more on Sundays and Mondays, and less on Fridays ³⁹ The range of weight variation is typically on the order of a few pounds or so, or about 1-2% of someone’s weight, but this can vary by season, holidays, and more. ^{40, 41, 42} 

Additionally, significant changes in body weight due to loss or gain of muscle and/or fat generally takes place over a long period of time, e.g. weeks and months,not hours and days. As described in the previous, shorter term weight changes are typically due to differences in body water. 

Frequent weighing that is done under similar conditions can produce a rolling average that can be used to analyze longer trends in weight change. These inputs would be a bit more indicative of what is happening at the tissue level. If you’re monitoring your weight and using it to guide the changes you make to your diet, we recommend combining two to four weeks of data to determine your energy balance and the effect it has on your body weight. 

Take-Home 

Gaining weight while exercising can be quite confusing and frustrating, especially if your main goal is losing or maintaining your current weight. Even so, knowing why the weight gain occurs, can help you navigate these changes more effectively. The main reasons for gaining weight while following a training program can be boiled down to eating too many Calories, fluctuations in hydration levels, and measurement error. 

If you’re exercising to lose weight, but are still gaining, we recommend that you do the following:

• Consider reducing your daily intake by 200 to 300 Calories daily. Use our free calorie calculator.
• Consume ~ 1.4 to  1.6 grams of protein per kilogram of total bodyweight per day coming from lean, predominantly unprocessed or minimally processed sources.We recommend using our free macronutrient calculator.
• Change the food environment by reducing access to foods with added sugar, added sodium, and increase availability of minimally processed foods in the home and work place to the extent that’s possible. 

• Make sure you’re meeting or exceeding the exercise guidelines for both lifting and conditioning. 
• Use a rolling average of bodyweight values to accurately assess trends in body weight.

And perhaps our most important recommendation…KEEP EXERCISING! Regardless of weight change, exercise is beneficial to health. If you have questions or need a helping hand, shoot us an email at support@barbellmedicine.com.

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