You've seen the ads showing men and women who supposedly lost weight while gaining an appreciable amount of muscle at the same time. Can it really be done? Common sense seems to dictate that if you lose 30 pounds, at least some of it will be muscle, right? Maybe not.
In a study reported in the American Journal of Clinical Nutrition (58:561-565; 1993), 'Muscle Hypertrophy With Large Scale Weight Loss and Resistance Training,' subjects took off fat while gaining muscle. Fourteen women followed an 800-calorie, high-protein diet'80 grams of protein, 97 grams of carb and 10 grams of fat'with seven of the women lifting weights for 30 to 40 minutes three days a week and the other seven women simply following the diet. The study ran for 90 days. The workout consisted of bench presses, pulldowns, military presses, pullovers, curls, triceps extensions, knee extensions and knee flexion.
At the end of the 90-day period each group averaged the same amount of weight loss'approximately 33 pounds. The lifting group, however, actually increased muscle mass by 21 to 27 percent, while the nonlifting group didn't increase muscle mass.
'These results indicate that weight training can elicit muscle fiber hypertophy during periods of severe energy restriction,' said the researchers. 'Strength declined in the sedentary group during the weight reduction but increased in the weight-trained group.'
The keys were weight training'not walking, which most weight-loss programs suggest'and a high protein intake. In the study 40 percent of the calories came from protein. Most weight-loss diets call for only 15 to 20 percent protein. IM