Promoting Physical Activity With the Out of School Nutrition and Physical Activity (OSNAP) Initiative A Cluster-Randomized Controlled Trial

IMPORTANCE Millions of children attend after-school programs in the United States. Increasing physical activity levels of program participants could have a broad effect on children's health. OBJECTIVE To test the effectiveness of the Out of School Nutrition and Physical Activity (OSNAP) Initiative in increasing children's physical activity levels in existing after-school programs. DESIGN, SETTING, AND PARTICIPANTS Cluster-randomized controlled trial with matched program pairs. Baseline data were collected September 27 through November 12, 2010, with follow-up data collected April 25 through May 27, 2011. The dates of our analysis were March 11, 2014, through August 18, 2015. The setting was 20 after-school programs in Boston, Massachusetts. All children 5 to 12 years old in participating programs were eligible for study inclusion. INTERVENTIONS Ten programs participated in a series of three 3-hour learning collaborative workshops, with additional optional opportunities for training and technical assistance. MAIN OUTCOMES AND MEASURES Change in number of minutes and bouts of moderate to vigorous physical activity, vigorous physical activity, and sedentary activity and change in total accelerometer counts between baseline and follow-up. RESULTS Participants with complete data were 402 racially/ethnically diverse children, with a mean age of 7.7 years. Change in the duration of physical activity opportunities offered to children during program time did not differ between conditions (-1.2 minutes; 95% CI, -14.2 to 12.4 minutes; P = .87). Change in moderate to vigorous physical activity minutes accumulated by children during program time did not differ significantly by intervention status (-1.0; 95% CI, -3.3 to 1.3; P = .40). Total minutes per day of vigorous physical activity (3.2; 95% CI, 1.8-4.7; P < .001), vigorous physical activity minutes in bouts (4.1; 95% CI, 2.7-5.6; P < .001), and total accelerometer counts per day (16 894; 95% CI, 5101-28 686; P = .01) increased significantly during program time among intervention participants compared with control participants. CONCLUSIONS AND RELEVANCE Although programs participating in the OSNAP Initiative did not allot significantly more time for physical activity, they successfully made existing time more vigorously active for children receiving the intervention.