School and Family Influences on Adolescent Physical Activity, Sports Participation, and Weight Status

Problem Statement: Increasing physical activity is a priority for decreasing obesity rates, but we have a limited understanding of which factors are most influential in promoting physical activity among adolescents. We also do not know what forms of physical activity have the greatest impact on weight status.;Methods: Longitudinal telephone surveys were conducted with New Hampshire and Vermont adolescents and their mothers. In Study 1, adolescents (n=1,244) self-reported their sports team participation at baseline (elementary school) and follow-up (high school). Mothers reported their opinion of the importance of children's sports at baseline. We surveyed high school personnel to assess sports opportunities, including the number of sports offered and whether they restricted the number of players on team sports. In Study 2, adolescents (n=1,718) reported their team sports participation, active commuting, and physical education. Weight status was based on self-reported height and weight.;Results: Study 1) After controlling for children's baseline sports participation and other covariates, mothers' opinion of the importance of children's sports positively predicted boys' and girls' sports team participation in high school (RR=1.87, p=0.002, RR=2.95, p < 0.001, respectively). At the school level, boys played on more sports teams if their school did not restrict participation in the most popular sports (RR=1.20, p=0.001); in contrast, girls played on more sports teams if they had a wider variety of sports to choose from (RR=1.48, p<0.001).;Study 2) Overall, 29.0% of the sample was overweight/obese and 13.0% was obese. After adjustments, sports team participation was inversely related to overweight/obesity and obesity. Active commuting to school was inversely related to obesity. Estimates suggest obesity prevalence would decrease 26.1% (95% CI: 9.4%, 42.8%) if all adolescents played on two sports teams per year and 22.1% (95% CI: 0.1%, 43.3%) if all adolescents walked/biked to school at least four days per week.;Conclusion: Our findings suggest that promoting sports participation by improving family support and/or school opportunities for sports participation---including the variety of offered sports (for girls) and not restricting popular sports (for boys)---may lead to reductions in the prevalence of overweight and obesity.