[Juvenile obesity and the role of physical activity and inactivity].

Physical activity has important health benefits. Despite of the use of different measurement instruments, a decrease in physical activity and an increase in sedentary habits has been described in children and adolescents. As a consequence, a reduction in physical performance and motor abilities and an increase in overweight and fat mass is found associated with comorbidities, e.g., ranging from insulin resistance up to the metabolic syndrome. Therefore, beside the therapeutic use of exercise in obesity programs, adequate preventive strategies are warranted. However, within this discussion, it must be taken into consideration that special subgroups are more affected by insufficient physical activity/sedentary habits, e.g., females, adolescents, ethnicity, lower socioeconomic status. In many other groups, recommendations for physical activity (1 h/day) are achieved. Hence, interventions must focus on these at-risk groups and intensified. In addition, recommendations related to physical activity and inactivity, in terms of TV consumption, must be critically analyzed as to whether the recommendations are sufficient and how they can be implemented to achieve lasting results.