Effects of low- and high-intensity exercise training on body composition and substrate metabolism in obese adolescents.

摘要

The objective was to investigate the effects of a 3- week weight-management program including moderate energy restriction and exercise training at 2 intensities low intensity (LI): 40 and high intensity (HI): 70 maximal oxygen uptake (V'O(2)max) on body composition, energy expenditure, and fat oxidation rate in severely obese adolescents. Twenty obese adolescents, aged 15-17 yr (body mass index: 37.5 kg/m(2); 38.2 fat mass) participated in this study. Before starting (week 0, W0) and at the end of the weight-management period (week 3,W3), body composition was assessed by a multifrequency tetrapolar impedancemeter; basal metabolic rate (BMR), energy expenditure, and substrate oxidation rate during exercise and post-exercise recovery by indirect calorimetry. At W3, body mass and fat mass decreased significantly (p<0.005) in all groups, and the decreases were significantly greater in the LI than in the HI group (-8.1+/-1.6 vs -5.9+/-1.6 kg and -4.2+/-1.9 vs -2.3+/-1.7 kg, p<0.05, respectively). Predicted V'O(2)max, expressed in relative values, changed significantly only in the HI group by +0.010+/-0.006 l/(kg fat-free mass x min) (p=0.010). By contrast, no significant changes were observed at W3 in BMR, energy expenditure, and substrate oxidation rate during exercise and post-exercise recovery. In conclusion, LI (40 of V'O(2)max) physical activity favors fat oxidation and it seems advisable to encourage obese adolescents to perform LI physical activity which is more feasible and acceptable than intense exercise.