Correlates of physical activity in Portuguese adolescents from 10 to 18 years.

This study examined the association between demographic [age, sex, socioeconomic status (SES)] and socio-cultural [father, mother, sibling physical activity (PA); peers and physical education teacher influences] correlates and low, moderate and high levels of PA among Portuguese adolescents aged 10-18 years. A total of 3352 males and females attending basic and secondary schools, their parents and siblings were sampled across four regions of Portugal. PA was assessed with a psychometrically validated questionnaire. Multinomial logistic regression was used. Age was positively related with moderate and high PA. Boys and adolescents of high SES were more likely to participate in moderate and high PA. Adolescents were more likely to participate in high PA when theirs mother and sibling(s) also participated. Peers had a positive influence on participation in moderate and high PA, while physical education teachers did not have an influence. The results indicated that demographic and socio-cultural correlates--in particular age, sex, SES, mother and sibling PA, and peer influence--were significantly associated with adolescent PA. These results also suggested that interventions should focus on girls and low SES adolescents who face higher risk of inactivity.