Effects of body weight loss program on parameters of muscle performance in female obese adults

BACKGROUND: Body weight loss program may lead to a decrease in lean body mass affecting negatively muscle performance in obese subjects. Thus, the aim of this study was to examine the effect of weight loss on muscle performance in female obese subjects. METHODS: Eighty obese female adults were enrolled for a 2-month unsupervised aerobic training (UAT) plus nutritional program. In the pre- and post-intervention body composition was evaluated by hand-to-foot bioelectrical impedance method, body strength using handgrip test, and lower muscle power was assessed by a 5-repetition chair stand test (CST) and 30-s chair stand test (30sCST) wearing a dynamometer. RESULTS: Thirty-six subjects completed the protocol, 39% had high compliance (HC), while 61% had low compliance (LC) to exercise prescription. HC group showed a significant decreased body weight, percent of fat mass and lean muscle mass after training. Both groups significantly increased CST performance while only HC significantly increased 30sCST. No differences were found in CST muscle power in both groups between pre- and post-training. However, evaluation of muscle power during 30sCST showed significantly higher value in HC group than LC group after training. CONCLUSIONS: The results of our study show that although total lean muscle mass decreased after UAT, lower body muscle efficiency increased while muscle power did not change suggesting that in obese patients UAT can help to optimize weight loss and body efficiency. The data might be helpful for exercise professionals to evaluate correctly the muscle performance in obese adults after weight loss programs.