How Many Calories Does Muscle Really Burn? (and Why It’s Not About Calories Anyway)
The hallowed halls of the Academy of Broscience contain untold tomes of knowledge, wisdom, and recipes for “sick” pump stacks. Over the years, their scholars have elucidated the arcane esoterica of muscle confusion, thereby making it palatable for the layman. They discovered that any gram of carbohydrate eaten after dusk turns immediately to fat, and that curling in the squat rack engages more muscle fibers than curling elsewhere. Their field researchers are reportedly close to confirming the existence of spot reduction. But perhaps their greatest contribution to modern physical culture has been the establishment of the unassailable fact that muscle burns fifty times more calories than fat, at fifty calories per pound per day. (Even Dr. Oz says it, so it must be true.) As they have so painstakingly shown, adding twenty pounds of muscle increases your resting metabolic rate by 1000 calories. With that kind of leeway, you could eat a delicious twenty egg-white microwaved omelet with low-fat cheese and a side of plain oats and never worry about body fat accumulation!
This, of course, is complete nonsense. Broscience is not even peer-reviewed and their application for accreditation is still in administrative limbo.
No, but seriously: the idea that muscle significantly boosts resting metabolic rate is pretty much nonsense. Now, don’t get me wrong. I like muscle. Love it, even. Nothing I like more than a bit of lean mass, but I don’t like how this notion of “muscle burning fat at rest” has taken hold in the collective psyche. It leads to lofty expectations that come thundering down to shatter to pieces. It gets people on a single, obsessive fitness track where all they want to do is lift, lift, and lift (and eat, eat, eat) some more to the exclusion of other, perhaps more enjoyable pursuits. And, it can even negatively impact one’s health or progress toward desired body composition, either via overtraining the heavy lifting and undertraining the other stuff, like sprints, walks, hikes, and simple play.
Anyway, I came across an article several months ago detailing the author’s discovery that muscles don’t actually burn that many more calories than body fat. He doesn’t cite any specific studies, but he does cite Claude Bouchard, an obesity researcher from the Pennington Biomedical Research Center, who revealed that a pound of muscle, at rest, burns about six calories per day (and a pound of fat burns about two). That’s a far cry from the 50 calories per day figure “cited” by others. This number isn’t available in the abstract of some specific study. It’s drawn from extensive reading of the “biochemical and metabolic literature”. If you have literature to suggest otherwise I’m all ears. For the purposes of this post, though, I’ll take Claude at his word.
So, straight from the guy that studies this stuff for a living, muscle doesn’t burn a significant number of calories at rest. To illustrate the point let me quote the author of the LA Times article:
The 20 pounds of muscle I’ve gained through years of hard work equate to an added 120 calories to my RMR. Not insignificant, but substantially less than 1,000. However, I also engaged in a lot of aerobic activity and dietary restriction to lose 50 pounds of fat, which means I also lost 100 calories per day of RMR. So, post-physical transformation, my net caloric burn is only 20 calories higher per day, earning me one-third of an Oreo cookie. Bummer.
Or a single macadamia nut as the case may be. But that doesn’t mean having more muscle isn’t good for body composition and overall leanness, because it definitely is. Let’s look at some of the metabolic and other benefits of having more muscle mass.
Recent epidemiology (13,644 participating subjects) reveals that skeletal muscle mass strongly correlates with improved insulin sensitivity. With each 10% increase in skeletal muscle index (a measure of how much muscle is on one’s body), HOMA-IR (a measure of insulin resistance) saw a relative reduction of 11%. Folks with higher insulin sensitivity have better glucose control (carbs don’t destroy them) and lower rates of diabetes. Another study looked at the relationship between sarcopenia, or muscle wastage, and insulin resistance. There was a distinct relationship between sarcopenia and insulin resistance, independent of obesity, which can also exacerbate insulin resistance. So, based on epidemiology, a lack of muscle is linked to increased insulin resistance and poor glucose regulation. This should go without saying, but sarcopenia was also linked to obesity.
How does one get increased muscle mass? Why, by lifting heavy things. And what does lifting heavy things do to insulin sensitivity in addition to its effects on muscle mass? It improves it. To show this, a study placed older Hispanic adults with type 2 diabetes on a 16-week resistance training regimen and measured their baseline and post-treatment muscle mass and markers of insulin sensitivity. Folks in the strength training group got stronger, leaner, built more muscle mass, and developed more type 1 and type 2 muscle fibers. They also became more insulin sensitive. The increase in type 1 fibers, in fact, was strongly associated with the improvements in insulin sensitivity, as this graph shows. Note how the sedentary group didn’t do so hot in either department (increasing muscle mass or decreasing insulin resistance). That looks like a pretty strong link between increased muscle mass and insulin sensitivity to me.
Why is this important? Being insulin sensitive means you handle glucose well, which means less dietary glucose becomes body fat and less insulin is required to handle your business. This is far better than the idea of having a rumbling muscular engine idly burning calories as you watch TV, mostly because while the latter is a fun story to tell your bros at the gym, it’s not really true.
Having greater muscle mass also acts as metabolic reserve in times of trauma. I’m not talking about famine or starvation. I’m talking about car accidents, internal damage to organs, severe burns, cancer, sepsis, and catastrophic injury. A great review article (PDF) from five years ago summarizes the role skeletal muscle plays in recovery from and survival of trauma. In these unfortunate but very real instances, protein requirements shoot up to repair damage, and muscle protein breakdown increases. More muscle mass means you have more reserves to keep the amino acids flowing. When healing from burns, dietary protein needs increase to 3 grams per kg of bodyweight. If you can’t stomach that much or dietary protein isn’t available to you, it comes from existing muscle. And, if you don’t have much muscle to spare, you’re going to recover more slowly from severe burns. Same goes for cancer patients; those who have the greatest muscle mass tend to suffer fewer recurrences and live longer. Think of skeletal muscle mass as a buffer for hard times.
Finally, muscle looks good when attached to a human skeleton by tendons and covered with skin. And don’t we all want to look good naked, ultimately? Heck, I’d say this last one is enough reason to lift heavy things by itself.
Now that you’ve (hopefully) ceded the “idle muscle burns fat” idea, we need to go further. Let’s stop thinking of exercise and weight loss in mechanistic terms. Let’s not think of “burning” calories by subjecting our bodies to punishment. Sure, you could grind away and, with enough volume and intensity, “burn” off calories through sheer force of will. If your only concern is that you maintain low body fat, you could eat a bad diet and run fifteen miles a day. I did, and I was skinny. It “works.” But isn’t it much more freeing to realize that 80% of your body comp will come through proper diet, meaning you don’t have to grind on the treadmill and you can instead explore the joy of movement for its own sake? Isn’t it more elegant to imagine the hormonal cascade that heavy lifting jumpstarts and which gently nudges one’s physiology toward leanness and away from adiposity? Whether you see it as science, art, or a blend of both, the way we do things is more effective and enjoyable than hammering away at your fat stores.
Some may continue to hold their peace of mind ransom for those 500 calories of donut they just ate. That’s not me. While they’re waiting for “500 cal” to pop up on the elliptical’s readout, I’ll be eating real food, lifting heavy things, and appreciating the beauty of a complex physiological system allowed to do its thing. I suggest you do the same.
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Posted By: Mark Sisson
So, I won’t get big biceps by curling in the squat rack..WTF?
Thanks to Mark for noting the concept of metabolic reserve. It occurred to me when I started gaining muscle that beyond getting stronger, I was storing up heaps of extra protein for repair and for fuel, to be used as necessary by the body in just the right amounts, and with minimal insulin.
So I am very interested to learn about the protein requirements of burn healing, and I imagine that’s just the tip of the iceberg. No matter what challenge your body faces, whether trauma or daily wear and tear, it is vastly more advantageous when your body can provide for its own shifting nutritional needs without relying on the vicissitudes of food intake.
So hooray for lifting heavy things! It’s not just for bros. Everybody benefits from building muscle: old men, women, even small children. And it’s fun!
Nice post Mark, keep it up! Maintaining a healthy, active lifestyle makes you more functional in Life. Skinny doesn’t mean healthy!
Love it man!
Broscience = Awesome
I always thought muscle burned fat, or at least calories, but I never assumed it was a huge amount, and in fact based on my experience I agree wholeheartedly with this article.
What I know to be true is that the more muscle mass I have, the more quickly and easily I recover from illness and injuries. What I also know to be true is that I don’t have to work out every day on a different muscle group to ensure I stay fit and strong…. two days a week of full body seems to be plenty for me!
One thing I found interesting was that I had to take a month off because I injured my neck, upper back and rotator cuff (don’t ask me what I did lol) and I found that I really didn’t loose any of my definition or muscle mass; I lost some strength, but not a lot. My deduction was that it was because I continued to eat my high protein/fat/veggie diet and moved slowly for around an hour a day. Back in my high carb low protein days, I would have lost the majority of my definition in a month and been back to square one in strength. Of course I was not NEARLY as strong or defined back then as I am now.
I have to admit that I don’t always do enough critical thinking when I read, but I do highly value life experience, especially my own, and being Primal has allowed me to be healthier and stronger than I have ever been in my life.
So true. Although I don’t always agree with what’s taught in academia, seems my professors got this right when they gave me an estimate of about seven calories per pound:
http://www.fitnessmash.com/2011/03/muscle-doesnt-increase-metabolism-like-you-think/
There are a host of benefits to resistance training, but a lightning-fast metabolic rate ain’t one of ‘em!
It is certainly easy to get caught-up thinking more muscle=alot more eating. As Mark says this ends up being detrimental.
I can honestly say the best results Ive had with gaining lean muscle have been just eating good food, and not worrying about stuffing myself. This goes so against what is preached by nutrition professionals but I have found it to work effortessely.
Good article Mark. After reading the sources posted in the comments 5-6 cals per day makes sense.
But also don’t forget this is at rest. Typically those with increased muscle mass don’t sit around resting all day…they exercise that muscle through heavy lifting, walking, running, toe tapping, butt squeezes while sitting at your desk, or whatever you want; the muscle increases its caloric need, while the fat does not.
Not that it results in 50 cals per pound per day, but it might result in 10 cals per day vs 5, which for a 185# male with 42% lean muscle mass, would equate to an extra 390 cals per day.
Very good point that hasn’t really been addressed in all this. Muscle may not have an increased resting caloric requirement, but it will have a greater caloric requirement when active. Simply put, a 200 bro will expend much more energy than a 150 bro of the same BF % when doing the same exact physical activity.
So while broscience may have oversimplified things, you will require incrementally more calories the more muscle you have because the same daily and exercise activities require more energy to perform (though you will do them with superior power!).
THANK YOU FOR MENTIONING THIS! Active metabolic rate was completely ignored in this article. Mark only talked about resting metabolic rates, but the majority of the people here are primal. We move a lot. So IMO, the broscience numbers take precedence over couch-potato numbers.
Eloquent and uplifting post, Mark! Logical, as always. I am just so glad I found MDA.
Well, I don’t know if I can ever give up donuts entirely (does it count if you eat someone elses?)… but I sure appreciate my heavy lifting and interval training sessions
“Let’s stop thinking of exercise and weight loss in mechanistic terms. Let’s not think of “burning” calories by subjecting our bodies to punishment. ”
I really liked this statement. I find that language shapes our understanding. In America we are fond of mechanical, sports and war metaphors – and we seem to use these in order to understand how the human body works. We “battle cancer” we “fight viruses” we “burn calories.”
I wonder what language we should choose when talking about how the body works and how health is achieved. I think this would go a long way in helping us to better understand how it really works.
Iron Heart by Brian Boyle is great story and a perfect example of how extra muscle and fitness can save your life in a severe car accident when the average person would not make it to the hospital let alone live after having his organs put back where they belong including his heart which had relocated to the other side of his chest.
Mark, the first paragraph of this post rules! With all the bad snark on the internet, its great to see someone who can still do it right. (The rest of the post is great, too).
Broscience. Perfect.
Awesome awesome article
“Nothing I like more than a bit of lean mass,…” that’s what she said.
Sorry coudn’t resist
No evidence here, but just some “food” for thought.
While it might not be the additional muscle mass in and of itself that contributes to calorie expenditure, could it be the very processes that help maintain that muscle AND the additional work they contribute while exercising at high intensity that offers the real contribution of additional muscle.
The greatest expenditure while at rest comes from the internal organs and the brain, however those processes are involved in providing the energy required for cell turnover and fiber development.
All else being equal, larger stronger muscles will contribute more to any activity and calorie expenditure than smaller ones. Again, all else being equal.
I love it!!
I used to be on the hampster wheel, running up to 30 miles a day (training for ultraruns) ate anything I wanted. I thought I was really healthy! Now I perform body weight exercises, lift heavy stuff, swim, paddle and run medium short distances and practice yoga. I eat primal and feel much better and way stronger! I’m enjoying life!!!
Oh, I forgot barefoot running!!!!
I recently gave up on my Lotte Berke inspired workout DVDs in favor of Primal Fitness. The DVDs promise to whittle our hips and thighs if we do the dozens of plies every day for an hour. I kept hearing, “Feel the burn! Keep going! Ten more! This is your calorie-burning muscle! After this you can eat whatever you want!” I always thought it sounded like fiction, especially when my jeans got tighter instead of looser. Talk about frustrating. Now I know why. These days my jeans are looser doing less and eating Primal. Thank you for another nail in the CW coffin.
8000 calories a day!?! WOW!!!
Great post Mark!! Keep up the work. I have a question that is off the subject… in your experience do you think some women are turned off by fit men? Also, are some men intimitated by fit women? Just a topic to expand on…
Someone posted to the Nutrition and Metabolism Society FB group the other day about greater muscle mass being linked with less risk of insulin resistance. I wondered then whether it was because the muscle fended off the IR specifically, or whether it was because people with IR lose muscle mass–you need insulin to put amino acids into muscle, which is why eating protein triggers insulin release. But if muscles are IR already, they won’t be able to grow any and may even deteriorate, which probably explains the beach ball on a stick look that so many middle-aged people have (well, that and abdominal fat).
So I guess, from what you’re saying here, that actually both are true. Iiinteresting. And this points up why diet is so important. Building muscle might reduce the risk of IR somewhat, but ultimately diet has the greatest effect, and the less IR you have, the easier it will be to build up the muscles, which reduces the risk of IR further.
Cool!
@Dana, probably both as you note. Muscles get larger through lifting heavy things. When you lift heavy things, you must burn glycogen stored in the muscles, after which time those muscles want to restore gycogen levels. In order for that to happen they have to become receptive to the insulin that allows glucose (and amino acids for repair and growth) in. That’s why exercise is such a great “cure” for IR. It’s a constant depletion and refilling of glycogen that keeps insulin sensitivity.
OTOH, when you don’t exercise, you lose muscle mass and you don’t ever really tap into glycogen storage, so the insulin knocking at the door gets the response “nope, don’t need any more glucose here, take it somewhere else.”
The muscle mass correlation may have more to do with exercise growing muscle AND improving insulin sensitivity than just the observation that less mass correlates with IR. Either way, lifting heavy things will generally improve sensitivity AND mass.
That IS interesting. I was wondering, then, if a person is constantly needing to restore glycogen levels–and so the muscles are “sopping up” more of the glucose from the bloodstream–would less insulin be produced in the first place? (Since there would be less of a spike in blood sugar?) Or maybe it doesn’t work that way, I don’t really know. But I was thinking that anything that reduces the amount of insulin released would reduce IR?
This is particularly interesting to me because I just visited my 18-year-old, who’s been working on a trail crew for the last two weeks. It’s extremely hard physical labor, long days and they get very little protein or fat. And she’s lost a good deal of weight around her waistline and gained muscle. She was hardly overweight to start with but now her belly is sure flat. She already was pretty strong in the arms and shoulders from rock climbing and now she’s swinging a pick to crush rocks for trail drainage and cutting logs with a handsaw in the wilderness areas where power tools aren’t allowed…and building up more shoulder strength. I asked her if she was getting enough to eat and she said sometimes the mosquitoes are so bad they don’t want to lift their face netting to eat! So probably she isn’t getting enough fat, protein OR calories. This got me thinking both about the post earlier relating to countries where people eat almost entirely carbs and stay slim and the link to the article about how people shouldn’t jump to conclusions about the reasons people are overweight. Although I definitely don’t believe it’s all about “calories in/calories out,” calories and exercise do have a role, clearly. It just depends–there are a lot of factors. Well, I gave the girl a bag of protein bars and encouraged her to continue her practice of buying a quart of whole milk every time the trail crews stops at a mini-mart. (In camp, it’s mostly bread and pasta, every day, and they drink powdered sugar drinks right out of 5 gallon bins.) She’s a vegetarian, which makes it even more difficult to get enough calories, fat and protein on the job. But people can and do subsist on carbs.
Dennis, I agree completely!
Rob & Jason
At no point did Mark make a plea that you must believe him or the article sited. All he did was give a hypothesis and site a study that supports it and leads him to believe the way he does.
The purpose for this article was to pose a question and give a possible answer not come to a definitive conclusion.
If you have sone information that conflicts then state it. Don’t just bitch and complain that he didn’t do all your research and thinking for you.
An appeal to authority is saying, you must believe something because so and so believes it, not I believe something because someone I trust beleives it. The second one leaves it up to you to choose for yourself to believe or not, and is a statement of why he believes something not a cry for you to believe it to.
What do they teach in schools nowadays,
Josh
It’s like Coach Rippetoe says, “Strong people are harder to kill than weak people, and more useful in general.”
Put another way, “être fort pour être utile” — be strong to be useful. That was the motto of Georges Hébert, paleo forerunner and father of parkour.
Interesting how something people want to hear soon becomes a ‘well known fact’. Just to add, McArdle, Katch and Katch (2007) suggest that for every lb of lean muscle mass an additional 7kcal per day are burned.
I know many PT’s who use the 50kcal/lb/day ‘fact’ to sell personal training to their clients, and I can see why – for simplicity: Say you gain 10lbs of muscle, you will burn an extra 500kcal per day, so that’s 3500kcal per week. This is the number of kcal held in 1lb of fat, so therefore you will burn 1lb of fat per week at rest! SOLD!
Although resting metabolic rate might only be minimally influenced by muscle mass, what about metabolic rate while exercising?
Maybe a bodybuilder going for a walk/ run/ swim might only ‘burn minimally more calories’ than a skinny marathon runner, but imagine them ‘lifting heavy things’ to the best of their ability.
I know that, after a few sets of bodyweight pull-ups/ dips/ squats or bench presses etc, I’m hardly sweating (I’m 1.80m, 64kg, frustratingly losing weight), but huge guys (this kind of applies to fat guys too), after a few warm-up lifts are already in full workout mode; heart rate elevated, sweating unpleasantly.
Any thoughts?
Humans had been dead long gone if our muscles spent so much energy not doing anything. Everything´s evolved for survival. That includes saving energy!
Hello Mark,
Since the subject is muscle, I have a question. I’ve been reading your blog for several month’s now, and I love all of your diet advice you give here. I tried being primal for 2 month’s now, maybe a little longer.
Today, when I was looking through some of my pictures from 2 month’s ago, and some of my recent pics as well, I’ve noticed a huge difference in my body composition. I’ve lost a lot of muscle.
Before, I’ve always had a lot of muscle, I workout 4 times a week.
But in since I tried primal diet, I’ve lost so much muscle, my body doesn’t look the same as it did a few month’s ago. But I train the same, I am a bit confused.
When I started eating primal I initially had low energy and lost some muscle. It turned out I just had to adapt to the diet and eat more. That took some time as so much fat didn’t sit comfortably in my stomach so I had to split up my eating through the day to get all the necessary calories and eat lots of fruit for energy. Now, six months later, I normally drink tea or coffee and eat a bit of fruit and maybe small protein containing snacks through most of the day, as well as a big glass or two of milk during my workouts, and at night I FEAST on protein and fat.. a lot of it.. and I think I’m gaining muscle. I at least have lots of energy compared to before and I keep increasing my endurance. (That might just be due to getting in better shape but I think I just had to adapt after 20 years of eating high-carb). Maybe you should try adding more carbs into your diet from fruit to help with the transition because I think it takes at least a few months to truly get into primal mode.
Is there a whiff of an anti-gym agenda in some of the responses here? Some people seem to love to knock gym based lifters.
I know this isn’t the case, because Mark lifts heavy things in the gym, but the article does come across as a bit of a downer on gym based weight training. It just reads that way to me.
Remember folks, that lifting in the gym can get dramatically varying results. You can get fitter, leaner, stronger or bigger. It just depends on how you go about it.
Another great article. Have to love “Bro Science”! I really like the point on play being a larger part of our fitness. It can be fun to go into the gym and pound out a great workout but even there you have to keep it fresh, do new challenging movements, take it outside for a trail run or, even better, free running in nature. Learn something new. Play like children and if you have children, get outside and just play with them. That is what life is meant to be.