Some say that for every pound of muscle, your body will burn an extra 50-100 calories per day.
According to Adam Zickerman, author of Power of 10: The Once-a-Week Slow Motion Fitness Revolution, “three extra pounds of lean muscle burns about 10,000 extra calories a month.”
Zickerman also says that three extra pounds of muscle “burns as many calories as running 25 miles a week, or doing 25 aerobic workouts a month without leaving your couch.”
You’ve probably read similar claims that muscle “burns calories around the clock just to maintain itself, even while you are sleeping or sitting at a desk.”
When you gain muscle, your resting metabolic rate (the number of calories your body burns at rest) does go up. But this increase is a lot less than the 50-100 calorie figure you’ll often see written.
Where does the 50-100 calorie figure actually come from?
I have no idea. It just seems to be one of those myths that have been around for so long that its accuracy is no longer questioned, and probably exists for the same reason we have misconceptions about a lot of things.
Somebody says something, somebody repeats it, and then we repeat it. Suddenly it’s established as fact.
So, how many calories does a pound of muscle burn… really?
Muscle actually has a very low metabolic rate when it is at rest, which is most of the time. And the metabolic rate of muscle pales in comparison to other parts of the body.
In fact, the heart and kidneys have the highest resting metabolic rate (200 calories per pound). The brain (109 calories per pound) and liver (91 calories per pound) also have high values.
How Many Calories Does a Pound of Muscle Burn?
In contrast, the resting metabolic rate of skeletal muscle clocks in at just 6 calories per pound, with fat burning just 2 calories per pound .
|Organ or tissue||Daily metabolic rate|
|Fat||2 calories per pound|
|Muscle||6 calories per pound|
|Liver||91 calories per pound|
|Brain||109 calories per pound|
|Heart||200 calories per pound|
|Kidneys||200 calories per pound|
In other words, while skeletal muscle and fat are the two largest components, their contribution to resting energy expenditure is smaller than that of organs.
The vast majority of the resting energy expenditure of your body comes from organs such as liver, kidneys, heart, and brain, which account for only 5% to 6% of your weight.
As is often the case with such matters, not everyone agrees on the exact figure.
Writing in the American Journal of Clinical Nutrition, Robert Wolfe, Ph.D., Chief of Metabolism and Professor of Biochemistry at the University of Texas Medical Branch, points out that “every 10-kilogram difference in lean mass translates to a difference in energy expenditure of 100 calories per day, assuming a constant rate of protein turnover.” 
That’s 10 calories per kilogram of muscle, or a little less than 5 calories per pound — not too far away from the previous estimate of 6 calories per pound.
I do want to make an important distinction between resting muscle and recovering muscle.
The estimates of the resting metabolic rate of muscle I’ve just given do make one assumption — a constant rate of protein turnover.
However, most types of resistance exercise will accelerate protein turnover (an increase in the rate of protein synthesis and breakdown), which is going to increase calorie expenditure in the hours (and, in some cases, days) after exercise.
And there are studies to show that the more muscle you have, the more calories you’ll burn after an intense workout .
When exercise ends, it takes time for everything to get back to normal. Depleted glucose and fat stores need to be refilled. Damaged muscle cells need to be repaired. All of this requires energy.
And the more rebuilding that has to be done, the more calories (mainly from fat) are being burned after your workout is over.
Or to put it another way, while the metabolic rate of resting muscle isn’t as high as previously thought, the metabolic rate of recovering muscle means that people with more muscle mass are going to burn more calories in the post-exercise period.
What does all of this mean for you?
If you were to lose two pounds of fat and replace it with two pounds of muscle, your resting metabolic rate will increase by less than 10 calories per day.
It would take a vast amount of muscle to substantially increase your metabolic rate — far more than most people are going to build in the gym.
Which brings me to another important point.
Unless they’re very overfat, returning to exercise after a layoff, or just starting an exercise program, very few people gain a lot of muscle and lose a lot of fat at the same time. Your body just isn’t that great at doing both things at once.
That’s why I recommend you focus on one of two goals when you’re trying to get in shape — building muscle while minimizing fat gain, or, losing fat while preserving muscle.
Despite the fact that the resting metabolic rate of muscle is not as high as previously thought doesn’t mean that training with weights is pointless if you want to lose fat. Far from it. In fact, lifting weights will improve your body composition in a number of different ways.
Firstly, strength training burns calories (and fat). Not just during your workout, but – provided you train hard enough – after it’s finished as well.
Second, if you don’t do some kind of resistance exercise while you’re dieting, a lot of the weight you lose will come from muscle as well as fat.
If you are fortunate enough to gain a significant amount of muscle while you’re losing fat, the impact of the extra muscle on your resting metabolic rate will be small, and certainly won’t amount to 10,000 extra calories a month.
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