[Prevalence of sedentary lifestyle and associated factors in adolescents 10 to 12 years of age].

Physical activity in adolescence is associated with several health benefits, including a direct influence on adolescent morbidity and an indirect effect on adult health mediated by physical activity levels in adulthood. This study assessed the prevalence of sedentary lifestyle and associated variables in 4,452 adolescents aged 10-12 years, belonging to the 1993 Pelotas Birth Cohort Study, representing 87.5% of the original cohort. Sedentary lifestyle, defined as < 300 minutes per week of physical activity, was reported by 58.2% (95%CI: 56.7-59.7) of the cohort. In the multivariate analysis, sedentary lifestyle was positively associated with female gender, socioeconomic status, maternal physical inactivity, and television viewing, but inversely correlated with time spent playing videogames. Adolescents with low socioeconomic status were more likely to walk or bicycle to and from school. Effective strategies against sedentary lifestyle in adolescence are needed because of its high prevalence and association with physical inactivity in adulthood.