Most people know that muscle burns more calories than fat but, just how much more? Over the years I've heard that a pound of muscle can burn anywhere from 30-100 extra calories a day, but finding an exact number can be a challenge.
More than one study has shown that untrained men who lifted weights could burn an extra 30-35 calories for each pound of muscle gained.
However, other experts, including Dr. Cedric X. Bryant, the American Council on Exercise's Chief Science Officer, suggest a pound of muscle only burns about 6 calories a day.
So why the difference? The confusion exists because of different studies using different ways to test metabolic changes after exercise. There are other mechanisms involved with metabolism as well (including gender, age, fitness level and how active you are otherwise) and, frankly, there's still plenty of controversy about how much exercise really influences metabolism.
Some readers have emailed me after reading this, discouraged about their weight training goals. They wonder: "If I'm not burning as many calories as I thought, what's the point of lifting weights?" Whether you believe muscle burns 6 calories or 60 doesn't change the fact that strength training is incredibly important for losing fat and keeping your body strong and healthy. Just some of the benefits include:
- Increased after burn - High intensity strength training can actually help you burn extra calories for hours after your workout
- Prevents loss of lean body mass that happens from dieting and/or aging
- Burning calories - While strength training doesn't burn as many calories in one sitting as cardio, it does contribute to your overall calorie expenditure
- Changes your body composition, which helps shape your body and keep you healthy
- Strengthens bones and connective tissue along with muscles
- Keeps you strong and active as you get older
- Improves coordination, balance and may help prevent injuries
The bottom line is, strength training is important for almost any fitness goal, whether you want to lose fat, gain muscle or just get in better condition. Check out the following strength training resources for more:
Bryant, Cedric X. Ph.D., Chief Exercise Physiologist. (2006, March/April). ACE Fitness Matters, p. 6.
Heymsfield SB, Gallagher D, Wang Z. Body composition modeling. Application to exploration of the resting energy expenditure fat-free mass relationship. Ann N Y Acad Sci. 2000 May;904:290-7.
Poehlman, Eric T., et al. Effects of Endurance and Resistance Training on Total Daily Energy Expenditure in Young Women: A Controlled Randomized Trial. J Clin Endocrinol Metab. 2002 Mar;87(3):1004-9.
Pratley R, Rubin N, Miller J, et al. Strength training increases resting metabolic rate and norepinephrine levels in healthy 50- to 65-yr-old men. J Appl Physiol 76: 133-137, 1994.
Stiegler P, Cunliffe A. The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during weight loss. Sports Med. 2006;36(3):239-62.
Wang, Z., et al. Resting energy expenditure: Systematic organization and critique of prediction methods. Obesity Research. 2001 May;9(5):331-6.
The Facts About Fitness. What they told you about muscle and your metabolic rate is wrong. Retrieved Oct 4, 2010.
Van Etten, L.M., et al.. Effect of an 18-wk weight-training program on energy expenditure and physical activity.. J Appl Physiol. 1997 Jan;82(1):298-304.