Childhood obesity, Exercise, Insulin resistance, Microvasculature, Physical activity, Nutrition. Foods and food supply, TX341-641, Nutritional diseases. Deficiency diseases, RC620-627

Objective: The effects of a training program (TP) on muscle microvascularization during exercise remained to be explored in adolescents with obesity. We hypothesized that a TP would lead to better microvascular adaptations to exercise in skeletal muscle. Methods: 15 inactive adolescents followed a 12-week TP where both peripheral (muscular microvascularization) and central (cardiac) adaptations to exercise (40 min exercise set at 70% V̇O2peak) were assessed before and after intervention. Microvascular adaptations were evaluated in the Musculus vastus lateralis with near-infrared spectroscopy, by measurement of muscular blood volume (IR-BV) and tissue oxygen saturation (IR-SO2). Central adaptations were evaluated using thoracic impedance. Results: The TP favored lower BMI (p 2peak relative to weight (p = 0.008) and maximum power output increased (p = 0.0003). A smaller initial drop in IR-BV and IR-SO2 (p 2 all times taken together (p Conclusion: We demonstrate for the first time by noninvasive techniques that a training program induces peripheral and central vascular adaptations to exercise in adolescents with obesity.