Physical activity and self-reported health status among adolescents: a cross-sectional population-based study

Objectives: Little is known about the dose–response relationship between physical activity and health benefits among young people. Our objective was to analyse the association between the frequency of undertaking moderate-to-vigorous physical activity (MVPA) and the self-reported health status of the adolescent population. Design: Cross-sectional study. Setting: All regions of Spain. Participants: Students aged 11–18 years participating in the Spanish Health Behaviour in School-aged Children survey 2006. A total of 375 schools and 21.188 students were selected. Main outcomes: The frequency of undertaking MVPA was measured by a questionnaire, with the following four health indicators: self-rated health, health complaints, satisfaction with life and health-related quality of life. Linear and logistic regression models were used to analyse the association, adjusting for potential confounding variables and the modelling of the dose–response relationship. Results: As the frequency of MVPA increased, the association with health benefits was stronger. A linear trend (p<0.05) was found for self-rated health and health complaints in males and females and for satisfaction with life among females; for health-related quality of life this relationship was quadratic for both sexes ( p