Effects of a 30-week combined training program in normoxia and in hypoxia on exercise performance and health-related parameters in obese adolescents: a pilot study.

BACKGROUND: A light but regular combined training program is sufficient to improve health in obese adolescents. Hypoxia is known to potentiate the effects of a high intensity period of combined training on exercise performance and glucose metabolism in this population. Here, we tested the effects of a less intensive hypoxic combined training program on exercise performance and health-related markers in obese adolescents. METHODS: Fourteen adolescents volunteered to participate to a 30-week combined training protocol whether in normoxia (FiO2 21%, NE, N.=7) or in hypoxia (FiO2 15%, HE, N.=7). Once a week, adolescents exercised for 50-60 min including 12 min on a cycloergometer and strength training of the abdominal, quadriceps and biceps muscles. RESULTS: Combined training reduced body mass (NE: -12%; HE: -8%), mainly due to a loss in fat mass (NE: -26%; HE: -15%), similarly in both the hypoxic and normoxic groups. After training, maximal O-2 consumption (VO(2)max) (NE: +30%; HE : +25%,), maximal aerobic power (MAP) (NE: +20%; HE : +36%), work capacity and one-repetition maximum (1RM) for the quadriceps (NE: +26%; HE : +12%), abdominal (NE: +48%; HE : +36%) and biceps muscles (NE: +26%; HE : +16%) were increased similarly in both groups but insulin sensitivity markers were not modified. CONCLUSIONS: Except for insulin sensitivity, 1h a week of combined training for 30 weeks improved morphological and health-related markers as well as exercise performance in obese adolescents in both normoxic and hypoxic conditions. This is of particular importance for motivating those adolescents, who often are reluctant to exercise. Even a low dose of exercise per week can induce positive health outcomes.