Physical activity and associated socio-demographic factors among school adolescents in Jiangsu Province, China

Obesity prevalence is increasing among adolescents in China, especially in urban areas and among higher socio-economic strata. Physical inactivity may be one of the causes. We examined socio-demographic differences in physical activity among school adolescents in Jiangsu Province. In 2002, 824 adolescents (12–14 years) in 8 schools filled in a self administered questionnaire on physical activity, sedentary behaviors and socio-demographic characteristics. In girls, low SES elicited the highest physical activity score, mainly derived from housework. More boys (49.1%) than girls (41%) had vigorous physical activity (VPA) ≥3 times/week. Associations between VPA and residence, age, SES were not significant. 88% of the adolescents were actively commuting to schools. Boys with high SES or high education fathers had the lowest percentage walking to school. The students spent daily on average 10.8 h on studying, however, little time was spent on watching TV or playing PC games. Active commuting to school was common among the adolescents. However, the sedentary activity level is high. Physical activity was negatively associated with SES.