The 50 Calorie Per Pound of Muscle Myth
I don't know how many times I've heard the saying, "You increase your metabolism by 50 calories for every pound of muscle you add to your body."
50 calories per pound???? Really????
Let's take a look at this. I'm about 180 pounds. When I first started weight lifting, I weighed about 135 pounds. I've added a little bit of body fat since then, so let's be conservative and say I've gained 30 pounds of muscle since I started weight training.
If I've gained 30 pounds of muscle, that means that my metabolism should have increased by 50 x 30 = 1,500 calories.
I've had my resting metabolic rate (RMR) officially tested. The last time it was measured, it was 1,671 calories per day.
Now, if my RMR increased by 1,500 calories since I first started weight training, then that would mean my RMR started out at only 171 calories per day.
That is completely impossible. Nobody has a resting metabolic rate that low, unless you're dead.
Building muscle does not increase your metabolism by 50 calories per day. The real number is only 6 calories per pound on average.
So my 30 pounds of extra muscle has increased my metabolism by about 180 calories...not 1,500.
Adding muscle doesn't boost your metabolism all that much. Yes, it does a little bit, but you'll get more bang for your buck by simply being more active throughout the day.
Don't get me wrong. I'm not saying building muscle and strength training is not important. It's extremely important. It improves strength, it improves appearance, it improves function in activities of daily living, and it increases bone density. You also get a nice elevation of your metabolism of about 50-100 calories for 24 hours after your workout. My point is that building muscle is over-rated for permanently increasing your metabolism and energy expenditure.
The "50 calories per pound" number appears to be a case of communal reinforcement. This is the process by which a claim becomes a strong belief through repeated assertion by members of a community. Someone, somewhere, at one time proclaimed this 50 calorie per pound number. Other people heard it, believed it, and started telling their friends. It has now been repeated so often by so many people everywhere that people have accepted the number without question. Then you get doctors and other respected health professionals quoting the number, and it becomes permanently entrenched in our beliefs.
The fact is, muscle does not boost your metabolism all that much. Building muscle is important....just don't expect it to make you a calorie burning machine.
Only me… Evidently.
Listen chief, post a pic.
Then I’ll listen more carefully….
You built 30lbs of muscle? Are you sure you know what 30lbs of muscle looks like??
Does anyone else in here find this questionable??
Hell…. Forget the calorie expenditure arguments….
Yes, over a period of many years. Also went from doing dips with my body weight + 25 pounds to dips with my body weight + 135 pounds.
Yes
Only you apparently.
Also, even if it was only half that amount, the caloric expenditure numbers still don’t hold up.
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You RMR was officially calculated at 1671 calories But any RMR calculator I know off, from those more complex (where I guessed your stats a little) to those more approximate, says your RMR is way higher (from 1900 to 2100 calorie) Does that mean that every person who is trying to lose weight is working with overestimated numbers. On many forums I see people always claiming to petite young girls (5.2 feet and 110 pounds) how they should eat at least 2000 calories and to not fall victim of the mentality that they should eat little calories. It seems to… Read more »
Danny,
My measured RMR using a metabolic cart was 1,671 calories.
The Mifflin equation, which is one of the best equations for estimating RMR, gives me an estimate of 1,847 calories per day. Now, just because Mifflin overestimates for me, does not mean it overestimates it for everyone. On average, Mifflin does pretty well with its estimates. Some people will be underestimated and some people will be overestimated, but most people will fall in the middle and the estimates will be close to their true RMR’s.
Hopefully this clarifies things.
Jamal, Some studies on ketogenic diets show better fat-free mass preservation, while others show greater fat-free mass loss. The problem with all of these studies is that they look at fat-free mass and not muscle. If you’ve been reading my articles on body fat testing, you now know that simple changes in body water and fat-free mass hydration can alter body composition estimates. Because ketogenic diets can affect fat-free mass hydration and total body water content, there can be systematic error when comparing body composition estimates between outcomes of ketogenic diets versus non-ketogenic diets. The only way around this problem… Read more »
Keep it coming James! I love that you provide links to original research to back up what your write. Too often, the information I read seems to be rehashed lore that has gotten so far from the original source of scientific research. I have another suggestion for a different topic. I’m interested to know if there are studies comparing the effectiveness of various training techniques on maintaining and/or increasing bone density for women who are perimenopausal and beyond. For example, do low rep, high weight workouts do as well as a low weigh, higher rep workout? ie: Which is more… Read more »
Thanks for the suggestion, Ladybug. Bone density is always a concern for peri/post-menopausal women. I’m sure there’s some studies out there. I’ll put it on my future topic list
Jamal, I would agree that low protein is a bad idea. Not only will it contribute to muscle catabolism, but you will lose the satiating effect of protein. Regarding carbohydrate, it’s going to depend upon an individual’s activity levels and needs. Imagine a 200 pound athlete who trains on a regular basis and is trying to get leaner. He expends 4000 calories per day but is only consuming 3000. If he consumes 200 grams of protein (which is sufficient to maintain his muscle), that still leaves 2200 calories from carbohydrate and fat. This athlete could still consume 400 grams of… Read more »
Hi James,
Thanks for the article. The “50 calories per pound of muscle” was a claim that I never found any solid research behind so the links that you provided helped tremendously. However, do you know if there are any research on whether there’s any differences between the resting metabolic rate of type I, type IIa, and type IIb skeletal muscle fibers?
Also, if it’s worth anything, I feel that your debate with Fred wasn’t a total waste because I learned a lot from it.
Shoua,
Thanks for the comment. I am not familiar with any work at the RMR of individual fiber types. Theoretically, slow twitch fibers would have higher RMR’s than fast-twitch due to their higher mitochondrial and oxidative enzyme content.
Hi, Jamal, It isn’t true that you have to go low carb to keep your protein intake high enough to maintain muscle. There are plenty of bodybuilders who use more moderate carbohydrate intakes during contest preparation. There are even examples of ones using high carbohydrate intakes, but those ones typically also have high exercise volumes. Even for an overweight or obese person, there is plenty of room for a moderate carbohydrate intake and high protein intake. For example, imagine a 220 pound person consuming 2 grams of protein per kilogram of body weight. That’s 200 grams of protein, which is… Read more »
Hi, Jamal,
I don’t know of any studies that have specifically overfed protein and fat, while combining with low carbohydrate. There are some fat overfeeding studies, where they took people’s usual diets and fed additional fat (but no additional carbs), but the diets weren’t low carb.
I’ve really been enjoying this debate. Great stuff. 🙂