Background. To produce a synthetic global picture of the evolution of the level of extra
curricular sport activity [ESA] and to ascertain the presence of consistent long-lasting correlates of ESA throughout adolescence.
Methods. Data were obtained combining two nationally representative class-based surveys of adolescents aged 11 to 16 (HBSC) and 16 to 19 (SMASH) carried out in 2002 using self administered questionnaires (n=17817). Prevalence of low (< twice a week) ESA throughout adolescence was analysed in subgroups defined by demographic, psychological and emotional factors, and behavioural attributes. Analyses were stratified by age and sex to identify consistent and long-lasting correlates of low ESA using chi-square tests and logistic regressions with identical regressors.
Results. Low ESA increased from 29.0% to 66.7% for girls and from 12.3% to 44.6% for boys from age 11 to 19. ESA was consistently lower throughout adolescence for youth with poorer perceived health, non-Swiss girls and boys feeling too fat. ESA was higher for youth being on a diet (from age 16). In the logistic regressions, factors consistently associated to low ESA were: nationality (girls starting at age 11), poor perceived health (girls from 13, boys from 11), feeling too fat (boys from 14), dieting (inverse association, girls from 11, boys from 16).
Conclusions. Consistent correlates of low ESA appear at specific ages and last many years, providing opportunities for public health interventions aiming at increasing physical activity in adolescents.
