Abstract
Physical activity is a cornerstone of both prevention and treatment of childhood obesity. Skeletal muscle is a powerful fat oxidizer and its role in daily fat balance is crucial. Training increases fat oxidation rate both during exercise and in resting conditions. Reduction of physical activity promotes fat gain and vice versa. Data on obese adults showed a reduced mitochondrial oxidative capacity, which is partially reversible, by increasing physical activity. Available data demonstrate that reducing sedentary behaviour (video-exposition) and promoting light activity (walking) is helpful in promoting weight control in children. Moreover, especially in older children and adolescents, an increase of moderate-to-vigorous physical activity seems to be promising. Nevertheless, further studies are still necessary to design more effective preventive and treatment programs for childhood obesity.