Promotion of physical activity among high-school girls: a randomized controlled trial

OBJECTIVES: Many adolescent girls fail to meet national guidelines for physical activity, and the prevalence of obesity is increasing among this group. Our study examined the effects of a comprehensive school-based intervention on physical activity among high-school girls. METHODS: A group-randomized controlled field trial was conducted at 24 high schools. A school-based sample of 2744 girls (48.7% African American, 46.7% White) participated in a measurement protocol when they were in eighth and then ninth grade. A comprehensive physical activity intervention was designed to change the instructional program and the school environment to increase support for physical activity among girls. RESULTS: At follow-up, 45% of girls in the intervention schools and 36% of girls in the control schools reported vigorous physical activity during an average of 1 or more 30-minute time blocks per day over a 3-day period. CONCLUSIONS: A comprehensive school-based intervention can increase regular participation in vigorous physical activity among high-school girls.