Most of my newsletters are usually based around nutrition, in the next two newsletters let’s take a closer look at exercise. I am often asked how my clients get such phenomenal results. Let’s take a peek at The Plano Program fat blasting exercise strategies and some of the myths that surround muscle and fat burning.

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.”

The idea is that for every pound of new muscle, your body will burn an extra 60 calories per day. Add five pounds of new muscle and you will automatically burn an additional 31 pounds of fat in a year… or so the theory goes, anyway.

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.

In studies that have tracked changes in muscle mass and metabolism, it might appear that the metabolic rate of muscle is somewhere in the region of 50-100 calories per pound. But when you take a closer look, you’ll see that things are not quite so simple.

Let me give you a couple of examples…

The first comes from an 18-week study of 26 sedentary men published in the Journal of Applied Physiology . During the first eight weeks, the men gained roughly 2.8 pounds of fat-free mass. The average daily metabolic rate increased by 263 calories per day.

Dividing the increase in resting metabolic rate (263 calories) by the increase in fat-free mass (2.8 pounds) gives us a figure of 94 calories per pound. However, we can’t assume that this figure represents the metabolic rate of muscle.

Why not?

The first problem is the daily metabolic rate includes the energy cost of physical activity. We can’t say for sure that the increase in calorie expenditure was because of the extra muscle alone.

But that’s not the only problem.

From week 8 to week 18, the men gained another 1.8 pounds of fat-free mass. If muscle had such a big impact on metabolism, we’d expect to see another rise in the men’s metabolic rate. But this didn’t happen. Nor was there any change in sleeping metabolic rate during the study.

In another trial, women who trained with weights three days a week for six months gained 2.9 pounds of fat-free mass. In that time, their resting metabolic rate increased by an average of 60 calories per day.

Dividing the increase in resting metabolic rate (60 calories) by the increase in fat-free mass (2.9 pounds) gives us a figure of 20.7 calories per pound.

However, even this figure overestimates the metabolic rate of muscle.

Methods for measuring resting metabolic rate and body composition vary widely in their precision and accuracy. We don’t know for sure if the change in resting metabolism was because of the extra muscle, or whether it was due to measurement error. The control group in this study did no exercise, yet their resting metabolic rate increased by 31 calories per day.

In addition, other studies show an increase in resting metabolic rate even when gains in fat-free mass are taken into account. Researchers think that mechanisms other than the increase in fat-free mass (such as changes in the activity of the sympathetic nervous system) are partly responsible. And fat is not simply a “dead” tissue. It secretes proteins such as leptin and cytokines, which can affect your metabolism.

So, what is the “true” metabolic rate of muscle?
In her book Ultimate Fitness: The Quest for Truth about Exercise and Health, science writer for The New York Times Gina Kolata talked to Professor Claude Bouchard, a respected researcher in the field of genetics and obesity.

Bouchard points out that 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 [5]. 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
Adipose (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 these things, 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 for one 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.

Wolfe does mention that this number assumes “a constant rate of protein turnover.” Most types of resistance exercise will increase 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 [6].

“When exercise ends, it takes time and energy for muscle cells to return to resting levels,” says Chris Scott, Ph.D., exercise physiologist at the University of Southern Maine Human Performance Laboratory. “Recovery can also be expensive: Depleted glucose and fat stores need to be refilled, accumulated cell products need to be removed and protein levels need to be built back up. All this requires energy.”

And the more rebuilding to be done, the greater the rate of EPOC, which in turn means that more calories (mainly from fat) are being burned after your workout.

So, while the resting metabolic rate of muscle isn’t as high as previously thought, it is going to help you burn a few more calories after a workout is finished.

What does all of this mean for you?
Well, 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 your 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, resistance exercise will improve your body composition in a number of different ways.

Firstly, with a properly designed exercise program, you’ll burn calories (and fat) both during AND after your workout, although it’s my opinion that the light-weight, high-repetition “toning” workouts most people do have only a minor impact on post-exercise metabolism. Those who have great results with The Plano Program know that nutrition is always addressed first and then the MAGIC happens when the nutrition component is coupled with the metabolic conditioning exercise (moderate to heavy weights in superset fashion) is used. The moderate to heavy weight training in correct sequence is SUPER DEMANDING on metabolism for days on end.

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….but with the correct training variables we can manipulate metabolism immensely.

In the next newsletter we will take a closer look at metabolic conditioning my clients use to blast fat….and I guarantee you, it’s not doing moderate intensity cardio or using pink dumbbells.

References
1. Poehlman, E.T., Denino, W.F., Beckett, T., Kinaman, K.A., Dionne, I.J., Dvorak, R., & Ades, P.A. (2002). Effects of endurance and resistance training on total daily energy expenditure in young women: a controlled randomized trial. Journal of Clinical Endocrinology and Metabolism, 87, 1004-1009
2. Pratley, R., Nicklas, B., Rubin, M., Miller, J., Smith, A., Smith, M., Hurley, B., & Goldberg, A. (1994). Strength training increases resting metabolic rate and norepinephrine levels in healthy 50- to 65-yr-old men. Journal of Applied Physiology, 76, 133-137
3. Van Etten, L.M., Westerterp, K.R., Verstappen, F.T., Boon, B.J., & Saris, W.H. (1997). Effect of an 18-wk weight-training program on energy expenditure and physical activity. Journal of Applied Physiology, 82, 298-304
4. Wajchenberg, B.L. (2000). Subcutaneous and visceral adipose tissue: their relation to the metabolic syndrome. Endocrine Reviews, 21, 697-738
5. Wang, Z., Heshka, S., Zhang, K., Boozer, C.N., & Heymsfield, S.B. (2001). Resting energy expenditure: systematic organization and critique of prediction methods. Obesity Research, 9, 331-336
6. Smith, J., & McNaughton, L. (1993). The effects of intensity of exercise on excess post-exercise oxygen consumption and energy expenditure in moderately trained men and women. European Journal of Applied Physiology, 67, 420-425