MUSCLE HYPERTROPHY WITH LARGE-SCALE WEIGHT-LOSS AND RESISTANCE TRAINING

The combined effects of exercise and energy restriction on changes in body fat and fat-free mass (FFM) are controversial. This study was con ducted to determine whether muscle hypertrophy is possible during weig ht loss. Fourteen obese females received a 3360-kJ/d liquid diet for 9 0 d. Seven subjects received a weight training (WT) regimen and seven subjects remained sedentary (C). Biopsy samples were obtained from the vastus lateralis muscle at baseline and after 90 d of treatment. The average weight loss over the 90-d period was 16 kg with almost-equal-t o 24% of the weight loss from FM and 76% from fat. The amount and comp osition of the weight loss did not differ between WT and C groups. The cross-sectional area of slow twitch and fast twitch fibers was unchan ged by treatment in C subjects but significantly increased in WT subje cts. It appears that weight training can produce hypertrophy in skelet al muscle during severe energy restriction and large-scale weight loss .