The Myth of Metabolic Capacity

I’ve mentioned before that I do not think physique competitors are accurate in calling themselves athletes. I say this because athletes train for optimal human performance, while physique competitors train for optimal human appearance. 

Looking good on stage very often necessitates following diet and training protocols that are designed to diminish performance – low-carb, tons of cardio, diuretics, etc. Even gymnasts, who are notorious among athletes for pursuing low body mass for a competitive advantage, still eat enough to maintain a weight that makes them lithe yet powerful on the implements and gives them endurance on the floor. Meanwhile, physique competitors are pushing well past the boundaries of reasonable bodyfat ratios to achieve paper-thin skin at the price of not only physical functioning but also mental sharpness.  As a bodybuilder, figure or bikini competitor, almost everything you do to look your best makes you feel awful and perform worse.

Gymnasts aren't judged on their vascularity and hardness, but they still train to be as lean as possible while maintaining optimal performance.

Gymnasts aren’t judged on their vascularity and hardness, but they still train to be as lean as possible while maintaining optimal athletic performance.

This isn’t a knock on physique competition. I really do love this sport, and I recognize that pushing past those limits is kind of the point. Developing an extraordinary physique requires some extraordinary measures. But you only enter the danger zone for 4-8 weeks of your prep. What happens the rest of the year?

“Metabolic Capacity”

Which one of these little guys has optimized his metabolic capacity?

Which one of these little guys has optimized his metabolic capacity?

Maybe you’ve seen this term floating around the web lately. In bodybuilding circles, its been used to explain a method of offseason prep called reverse dieting, which you can see explained by the anti-guru Guru (and progenitor of the metabolic damage / capacity phenomena) Dr. Layne Norton in his vlogged manifesto.

Although reverse dieting isn’t really a new concept (Gaspari was talking about it in the early 90s), the claim that one can “optimize metabolic capacity” (i.e. increase your resting metabolic rate) by reducing energy output and increasing energy intake very gradually, all while maintaining a stable body weight or even losing weight is a bold concept.

I also think it’s misleading, inaccurate, and another example of how physique competitors & coaches ignore the basic tenets that form the backbone of every athlete’s long-term training & nutrition strategy.

But before I go into all that, let’s review some basics.

What is Metabolism, Really?

The word “metabolism” is often used casually to mean a handful of different things. In this case, “metabolic capacity” is referring to how many calories you burn, or the calories out part of the energy balance equation.


Weight control is determined by the balance of how much energy you consume minus how much much you expend. AKA The Energy Balance Equation.

There are 2 factors that together can very reliably determine your “Calories Out”:

(1) How much you weigh; and

(2) How much you move.

Number 1 determines your Basal Metabolic Rate (BMR). In the figure above, this is labeled “bodily functions”. Heavier people just need more energy to survive than lighter people do.  While BMR can vary between individuals with same body composition, lean body mass (LBM) is a very reliable indicator of BMR, even in select subgroups such as female athletes.


The Katch-McArdle BMR equation

Number 2 is a process we are all very familiar with. Being physically active requires energy beyond what you burn just staying alive. This is why I added daily cardio to my routine when my fat loss slowed down in the final weeks before my figure competition. It’s also why weight loss programs usually prescribe a combination of diet & exercise. By attacking the energy balance equation from both sides (eating less and moving more), you increase your chances of success.

“Metabolic Damage”

You are probably familiar with the problem of the weight loss plateau. Often, individuals who have lost a significant amount of weight will be unable to lose those last 5-10 lbs. When they were overweight, their diet may have resulted in a negative energy balance that promoted weight loss. However, their now reduced body mass requires fewer calories. That means no more energy deficit, ergo no more weight loss.


In the bodybuilding world, the term “metabolic damage” has been used to describe something similar. Figure and Bikini competitors have come forward in droves, describing gaining or maintaning weight despite doing hours of cardio per day on extremely restrictive diets (a practice that should theoretically result in a negative energy balance). There is a lot of debate as to whether or not what these women are suffering from is due to having actually damaged their body’s metabolic pathways and reduced their BMR, or is due to a complicated hormonal response to extreme stress. Until there is legitimate experimental research on physique competitors investigating the phenomenon, we won’t be able to pinpoint the true cause.

However, there is some evidence that your BMR can slow down more than you would expect just based on reduced body weight.

Adaptive Thermogenesis: a decrease in energy expenditure beyond what could be predicted from body weight or its components (fat-free mass and fat mass) under conditions of standardized physical activity in response to a decrease in energy intake

Due to a poorly understood process called adaptive thermogenesis, a formerly overweight person’s BMR may even be lower after dieting than the BMR of a person with identical body composition who was never heavier and didn’t lose weight. In practice though, the actual difference is fairly small. For example, a formerly overweight 132lb woman would burn about 120 fewer calories per day than a woman who has been 132 lbs her whole life. That isn’t even a 1/2 cup of plain oatmeal.


Adaptive thermogenesis also takes years to reverse. So far, it appears as though the metabolic adaptations to weight loss are, for all intents and purposes, irreversible. Furthermore, the few studies investigating the phenomenon thus far have been in overweight and obese individuals, not athletes or ultra-lean physique competitors. Therefore, it’s impossible to say whether adaptive thermogenesis can explain “metabolic damage”, and extremely unlikely that reversing these adaptations accounts for the claims Dr. Norton and others have made about enhancing metabolic rate in Figure and Bikini competitors, particularly within the time frame they describe.

The take-home message for competitors and coaches is that lean body mass is a very reliable predictor of the number of calories an individual burns before adding in physical activity. Unless you’ve lost 100 lbs recently, chances are high that a standard formula will give you an accurate approximation of your BMR.


You might be as special and unique as a snowflake, but your metabolism probably isn’t.

So if the only way to change your BMR significantly is by either gaining or losing mass, why are bodybuilding coaches suggesting that eating more and training less can force your body to “absorb” excess calories in the absence of weight gain? 

The Missing Link: Performance-Based Training

This is where the bodybuilding world reveals its disconnect from athletic training. While the average physique coach may obsess over his client’s caloric intake, macros, and meal timing, he often underestimates the role her training plays in determining her energy balance and ultimately her body composition. In particular, physique coaches often overlook the link between nutrition and training intensity, seeing them purely as weights on either side of the energy balance, instead of highly interrelated variables in an athlete’s progress towards her performance goals.

Athletic trainers, coaches and athletes, on the other hand, know that you need to eat to fuel your training. Marathoners carb-load prior to a race. Immediately after weigh in, powerlifters will break out the Pop Tarts and Gatorade for the same reason:

Consuming adequate food and fluid before, during, and after exercise can help maintain blood glucose during exercise, maximize exercise performance, and improve recovery time. —American College of Sports Medicine

Whether you’re running for 4 hours or squatting 800 lbs, you need adequate fuel. It’s the same reason Michael Phelps eats more calories for breakfast than your obese cousin consumes on Thanksgiving. (Obviously the video above is a joke, but apparently Phelps really does eat that much on a typical training day, and he isn’t particularly huge.)

Eating more may not change your BMR, but it does change how many calories you burn. Why? Because it gives you the energy you need to maximize your training potential. It allows you to have more intense workouts and more readily recover from them. Eating at a caloric surplus can even result in building skeletal muscle mass, which can actually augment your BMR, albeit by a very limited amount.

When you gradually increase caloric intake, you aren’t “optimizing your metabolic capacity”. You are finally fueling your body adequately to perform more intense workouts and recover from them. You are optimizing your work capacity.

It's not a coincidence that Ms. Figure Olympia is a former Division I athlete

It’s no coincidence that the reigning Ms. Figure Olympia is a former Division I athlete

To illustrate, say you are on a carb-cycling diet. You feel amazing on your high carb day, eating 400 calories more that day than you usually do. Thanks to that extra energy, when you get to the gym you are able to pump out a few extra reps on your weights and really push it with your HIIT intervals or whatever. This not only results in burning more calories that day, but also means you’ve pushed yourself further than you would have normally, improving your athletic ability overall, and giving yourself a greater capacity to burn calories when you train tomorrow.

But you know what you’ve haven’t done? Changed your BMR. Your body didn’t magically absorb an extra 400 calories. It burned them.

“Work Capacity”

What do I mean when I say work capacity? Well, much like pain tolerance, every person differs in how much training they can endure before they become mentally and physically exhausted. Advanced athletes, of course, will be able to train with greater intensity than novice or intermediate athletes. For example, ultramarathoner Pam Reed probably logs more miles during her off-week than your marathoning coworker runs during her peak training cycle. Olympic weightlifters under coach Ivan Abadjiev routinely lifted 90-95% of their one rep maximum multiple times per week, if not every day — a training regimen that would be impossible for most CrossFit Games competitors to even complete, let alone recover from sufficiently.

However, by consistently challenging yourself in a specific domain of athletic performance, be it strength or endurance, and tracking and forecasting progress over time, you will build your mental and physical tolerance for training intensity.  But you can’t up the ante if you don’t eat.

#hardcore #traininsane #beastmode

#hardcore #traininsane #beastmode

Pain ≠ Progress

You especially can’t enhance work capacity if, like many physique competitors, you don’t give a shit about performance. If you follow a new program every few weeks, the only way you keep track of your progress is with weekly selfies, and you measure how much you challenged yourself by how sore you are the next day, how much pump you got, or whether you felt like puking at the end of your workout, then the only thing you are going to enhance is your frustration.

Athletes challenge themselves in terms of seconds, miles, kilos or pounds because those are real numbers that actually mean something: progress towards a goal. When your body gets stronger, faster, more flexible and agile, it can just plain do more stuff.  It takes more energy to do more stuff. Ergo, the athlete often requires more calories each day as they get closer to competition, not less.  So, if you are a physique competitor, do yourself a favor and stop saying things like, “I don’t care how strong I am, I train for aesthetics”. Instead, try actually keeping track of your progress with real numbers like pounds on the bar, rep maxes, heart rate, and speed. Go ahead and post progress pictures on Instagram, but instead of the same boring abs & chest pose, snap a photo of an excel spreadsheet and let the numbers do the talking.

The Truth In the Myth

Even after all that,  I still wholeheartedly agree that physique competitors should eat more to fuel their metabolism in the offseason. And despite its tenuous scientific basis, the “metabolic recovery” protocol prescribes exactly this. It’s even safe to bet that it works as its proponents claim it does, just probably not due to the reasons they describe.

There is no argument from me that a Bikini competitor is going to be healthier, happier and improve her body composition when she switches from a 900 calorie-per-day diet and a fasted-cardio-and-glutes training plan to an adequate level of nutrition and a training plan based on heavy lifting and time for recovery.  But her recovery and progress should be recognized for what it is – hard work – and not confused for invisible calorie magic and metabolic voodoo at the hands of an all-knowing Diet Guru. If you are a physique competitor planning her offseason, please don’t fall for the myth that you can train yourself to eventually lose weight on 3500 calories per day by cutting out cardio and adding carbs in 5g increments every two weeks. Plan on eating as much as you need to get stronger, faster, and generally more awesome every day.

If you want to be an athlete, train and eat like one. And for God’s sake, quit it with the selfies and spend that time logging your workouts.

10 thoughts on “The Myth of Metabolic Capacity

  1. FWIW, even Phelps has denied he actually packs in 12k calories —

    As far as adaptive thermogenesis goes, this — — has a write-up on a pretty crazy AT study. Basically agrees that actual “metabolic slowdown” is responsible for maybe 100 calories/day and the main contributor is reduced voluntary and involuntary activity. Helps explain why people who combine intentional exercise with diet have an easier time maintaining weight loss (beyond the caloric deficit) and dovetails with your notion that being well fed enough to maintain exercise intensity is important, as opposed to those folks slumped over the step machine doing 3″ steps.

  2. Norton is not saying training less and eating more will get you results, he is saying that training smarter and eating the correct amount of macros/ fiber will get you results. He pushes HIIT cardio instead of hours on the treadmill, and calculates what you eat based on science. I don’t see any science documented in your article whatsoever. I don’t agree with a lot of the competitor diets out there but there are a number of teams and people doing it correctly so give them a bit of respect. It is definitely not an easy sport and it sure does require a huge amount of discipline and work. Look more into his studies and SUCCESS of his clients. He has a lot of validity on his arguments and definitions.

    • Hi kacia,

      I’m 100% in agreement with Dr. Norton that training smart and eating more will produce amazing results. I also respect him a great deal for speaking out about this issue and being a responsible coach.

      However, I don’t 100% agree with his explanation of the *cause* of the results he is getting with clients. This is something that researchers do all the time — we can agree on the outcome and even the methods, but disagree on the underlying mechanisms that are driving the phenomemon.

      The method Dr. Norton describes may not work for everyone, particularly those individuals who are are already fairly developed athletes and have a lot of smart training under their belt. I’ve heard personally from women who have reduced their training intensity and upped their calorie intake in an attempt to develop their metabolic capacity, but haven’t seen results.

      I wrote this post to put an alternative explanation out there that might help people who aren’t like the clients Dr. Norton typically coaches optimize their training and nutrition for their level of ability.

      Also, as for the scientific basis of these claims, there is no current research examining these phenomena in samples representative of physique competitors. I cited a few studies in my post that come close to it (specifically check out the stuff on adaptive thermogenesis and BMR in female athletes), but right now there is no scientific basis for metabolic capacity/damage. We’re all just explaining things as best we can.

    • NO, he’s saying taht gradually raises calories will raise BMR which it doesn’t beyond a tiny amount (maybe 10% if you overfeed by 1000 calories and never enough to prevent fat gain). If competitors are burning more calories, it’s for the reasons in this article and beacaue they weigh more.

      And I’ve looked into all the studies, Dr. Layne loves to use science when it suits him and ignore them when it doesn’t. Metabolic damage has 30 years of studies saying it’s not true and there are none to support his metabolic capacity ideas.

  3. I think that there are some good points in this article, and some not-so-well thought out points in this article.

    First and foremost, Dr. Norton is one of the most respected scientists in the bodybuilding industry, and his methods work for most clients. The science behind his “claims” are actually quite accurate from a nutritional standpoint – as I’m sure you know, when the body is in a severe deficit like many of these cardio bunny competitors are, the body goes into starvation mode, refuses to lose weight, and converts more energy to fat than in a healthy individual. This is commonly seen in individuals with eating disorders or those who live in impoverished nations. The body’s metabolism slows down. If a patient (or client, in the competitor’s case) adds in large amounts of food at one time, the body will convert most of this to fat. The body doesn’t know the difference between a famine and an intentional diet. This is why Dr. Norton and other supporters of the metabolic capacity idea add food slowly: so the client’s body will adapt to the increase in energy with as little fat gain as possible. During any “bulking” period, there will be some fat gain, but the goal of reverse dieting and maximizing metabolic capacity is to get the client back up to sufficient levels of energy intake with as little fat gain/change in body composition as possible. As for the term “damage,” Dr. Norton went on to re-coin the term “metabolic adaptation” due to the large uprising from people saying that metabolic damage doesn’t exist. So, damage simply wasn’t the right term. But do you not agree that the metabolism does in fact adapt to extremely low energy intakes?

    As for the “disconnect” from bodybuilders and what are considered “performance based athletes”: bodybuilding is, to a degree, performance-based. If a bodybuilder were not able to perform well in the gym, how would they ever build enough lean body mass to be stage ready? Much of a bodybuilder’s physique is based upon their performance in the gym, both in the off-season and during prep. A bodybuilder’s performance is just a very different kind of performance – there are many variables that go into the equation that vary from client to client: how much and what kind of cardio best suits them, what training split, what rep range, which exact area of the muscle to they need to zone in on the most. No, bodybuilders are not marathon runners or track athletes, but they still rely heavily on their performance.

    Additionally, one point you did not address was one of the main reasons Dr. Norton supports trying to maximize his clients’ metabolic capacity. During prep for a show, the athlete is required to cut energy intake to reduce weight/body fat. If you have 2 identical twins, and one is maintaining on 150 grams of carbs each day and the other has worked on her metabolic capacity and is consuming 350 grams of carbs per day, who will have more to cut from and will have an easier time during their prep? Clearly the person who is maintaining on 350 grams of carbs will be much better off in terms of energy, and thus will most likely have a better performance quality during their training.

    So, maximizing metabolic capacity is NOT a matter of eating more and training less. As someone mentioned above, it’s about training properly and eating more intelligently. It makes the off-season more productive, and not to mention much more enjoyable. That capacity will allow an athlete, male or female, to make necessary gains, enjoy life, and prepare effectively for their next season.

    Additionally, this was not meant to be an attack on your article. You made some valid points, I just felt that there were some other things that needed to be pointed out. Thanks for your post.

    • Thanks for the thoughtful comment. Sorry I’m just getting to it now (I don’t check this thing often).

      First off, let me just say that I’m not a Layne Norton hater. I actually really like the dude and know some of his happy clients. My criticism is directed at the misinterpretation of his observations by the larger community. However, I will note that the particular flavor of confident nerd-rage with which he describes his observations and methods in the video has a way of fueling misinterpretation. But that’s just his personality. I am glad to hear that he now calls it “Adaptation” as opposed to “Damage.” That happened a long time after I wrote this post.

      Now, to reply to some of your comments…

      First, the concept of “starvation mode,” whereby caloric restriction in a normal or overweight individual results in a reduction in the resting metabolic rate that is significant enough to counteract consistent negative energy balance and consequently impede or stop weight loss, is not well supported by the current literature except for the research I discussed earlier about adaptive thermogenesis. Although many will point to the hormonal response to dieting as the cause of a metabolism downturn, the evidence we have collected thus far on hormonal response to starvation suggests that these hormonal changes impede weight loss largely by increasing hunger and reducing satiety, not by making your metabolism slower. Yes, I do agree that the human metabolism will adapt to changes in energy intake. But that adaptation does not appear to be significantly greater than the change predicted by a reduction in body mass and activity, except for in some cases of large weight losses in obese individuals.

      In regards to transitioning between “bulking” and “cutting” diet methods, slow, gradual transitions in diet are not necessarily superior to sudden, drastic changes in diet when it comes to controlling body weight. The rate at which you increase or decrease caloric intake is not more or as important as the maintenance of a positive or negative energy balance over the specified time period. Of course, spending a week or two ingesting two to three times as many calories as you were eating prior to competing may result in weight gain. That is expected, since you are consuming more energy than your lean body now requires, especially since you have likely reduced your energy output due to fatigue.

      So, maximizing metabolic capacity is NOT a matter of eating more and training less. As someone mentioned above, it’s about training properly and eating more intelligently.

      Yes, I agree. I would take it a step further and specify that this “intelligent” way is known as “eating to fuel performance”. However, this concept appears to have been lost on many bodybuilding enthusiasts, who view it as metabo-magic and have begun marketing services that claim to “repair your metabolism” by prescribing sprints and an extra 1/4 cup of oats every two weeks. It’s another example of making a very simple, longstanding training tool seem mysterious, scary and unnecessarily complicated.

      Lastly, You are right that a bodybuilder’s success on stage is dependent on their training in the gym. However, very few bodybuilders actually focus on trying to improve their weight lifting ability because they do not lift weights on stage. Athletes, on the other hand, prioritize their athletic ability at every stage of preparation. Performance is their first priority, and they eat, sleep and train to improve it. Because a bodybuilder’s first priority is appearance, she will shape her diet, sleep and training to improve appearance at the expense of performance. When athletic performance suffers, so does metabolic output. But nobody recognizes this right off the bat, because nobody thinks about performance in the community. Ergo, it must be magic!

      Anyway, perhaps that clarifies some things I was trying to get at in the original post. I’m happy to have the discussion, so thanks again for your comments.

  4. Reblogged this on My Journey to Strong and commented:
    I found this article very informative – I feel like everyone needs to understand why they are training and getting healthy and realize everyone is not training for a competition or show. Most of us are just trying to be better versions of self.

  5. In the Biosphere 2 experiment

    “Consequently, 24-h EE remained lower in the biospherians than in the control subjects after adjustment for age, sex, fat-free mass, and fat mass (by 540 ± 240 kJ/d, or 6.7 ± 3.2%; P < 0.05; Figures 3 and 4⇑⇑). "

    There are 4.2 kj/kcal so this is about 130 calories per day (540/4.2). That can't explain what Dr. Layne is claiming. And adaptation is not damage in the first place. This is a normal adaptation to losing fat.

    Studies in the post-obese show that the adaptive component is about 5% below predicted once they are at maintenance calories (it's much lower while they are actively dieting). The majority if from weighing less. This is quantitatively insignificant in the big scheme of things.

    • It could become significant if you lost a very large amount of weight (e.g. 100 lbs), but that is an issue for bariatric surgery support providers to worry about, not bodybuilders.

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