The more muscle you have, the higher your basal metabolic rate is, which means that you burn more calories during rest and burn more fat when your muscles are active. You can lose muscle mass either by dieting or by focusing mainly on cardio/aerobic exercise, which primarily burns sugar and protein as fuel sources – and leaves fat untouched.
Studies have shown that people who do aerobic exercises increase their endurance by 11%, but they don’t increase their strength. On the other hand, people who do aerobics and resistance training have a 100% increase in their endurance plus a 20-40% increase in their strength! So the best choice for a workout is reasonable resistance training with low-impact cardio. Recently in the news there was a revealing study of elderly people related to this very topic:
Older people who diet without exercising lose valuable muscle mass
Contact: Christine Guilfoy
American Physiological Society
Sept. 17, 2008
A group of sedentary and overweight older people placed on a four-month exercise program not only became more fit, but burned off more fat, compared to older sedentary people who were placed on a diet but did not exercise.
The new study also showed that when older people diet without exercising, they lose more lean muscle compared to those who exercise, said senior researcher Bret H. Goodpaster. When they combined weight loss with exercise, it nearly completely prevented the loss of lean muscle mass. The results are important because older people tend to lose muscle mass as they age and too much muscle loss may interfere with activities of daily living.
The study, “Separate and combined effects of exercise training and weight loss on exercise efficiency and substrate oxidation,” appears in the current issue of the Journal of Applied Physiology, published by The American Physiological Society. Francesca Amati, John J. Dube, Chris Shay and Goodpaster, all of the University of Pittsburgh, carried out the study.
Study looks at exercise efficiency
The researchers wanted to know the best way to get better (more efficient) at completing a defined exercise task. In particular, they wanted to know if greater fitness could be achieved through exercise training, weight loss (through dieting), or both. In addition, they wanted to know which fuel source the body would draw upon, carbohydrates or fats, under these different conditions.
The 64 participants were 60-75 years of age and were either overweight or obese. All of the participants were sedentary at the outset of the study. The researchers divided the participants into three groups:
* exercise only
* diet only
* exercise plus diet
Those who exercised could either walk on a treadmill or ride a stationary bicycle, although most chose to walk. The dieters reduced their caloric intake to achieve a 10% weight loss by the end of the four-month study period. The final group combined both the daily exercise and the diet.
Exercise increases efficiency, burns more fat
The researchers measured how many calories the participants expended during a set work load on a stationary bicycle at the beginning and at the end of the experiment. They found that the:
* Exercise group expended fewer calories (became more efficient) on the exercise task at the end of the study compared to the beginning.
* Exercise group drew more on fat stores as the source of their body’s fuel.
* Diet-only group did not gain efficiency in performing the exercise task, even though they weighed less at the end of the experiment.
* Diet-only group’s weight loss resulted from a loss of both muscle and fat.
* Exercise plus diet group was the most efficient at the exercise task at the end of the experiment. This shows an additive effect of both dieting and exercise, but most of that benefit was due to exercise.
* Exercise plus diet group, like the exercise-only group, drew more on fat stores as an energy source.
“The take-home message is that, even among older people and during a fairly short period of time, exercise produces metabolic changes that require the expenditure of fewer calories during physical activity,” Goodpaster said. Exercise also allowed older people to more preferentially burn fat, which may be healthier metabolically.”
Low calorie diets deprive our bodies of nutrition, and they cause a loss of the very muscle tissue that is the metabolic engine where fat is burned. Losing 1 ounce of muscle lowers the body’s ability to create energy most needed for daily activities. 1 pound of active muscle can burn 50 calories a day (and there are 3,500 calories in 1 pound of fat!) So if we loose muscle tissue, our metabolism goes down the drain…
More useful information can be found at fatwars.com.Share