Impact of an 18-month school-based intervention on physical activity among elementary and middle school children

Introduction: The HEROES (Healthy, Energetic, Ready, Outstanding, Enthusiastic Schools) Initiative is a school-based childhood obesity prevention program to help schools in Southern Indiana and Illinois change their culture by implementing the U.S. Centers for Disease Control and Prevention's Coordinated School Health Model (CSHM). To evaluate the impact of the HEROES Initiative on physical activity among elementary and middle school students who were exposed to the program for 18 months.

Methods: Students who participated in physiological data (weight and height) collection were invited to participate in a survey that collected socio-demographical and behavioral data at baseline, 6 months, and 18 months (N = 1091, 8 schools). The dropout rate at 18 months was 16.9%. Data from the students who provided both physiological data and survey data were analyzed using generalized estimating equations (GEE). All the analyses were performed using SAS 9.2, accounting for clustering effects within the same school.

Results: A significant increase (p = .0067) was observed in vigorous-intensity physical activity (VPA) but a nonsignificant increase (p = .1753) in moderate-intensity physical activity (MPA). Students' screen time and vegetable/fruit intake were independently associated with both VPA and MPA increases. Body mass index of students was not predictive of VPA or MPA changes. Each school's implementation fidelity score was only associated with VPA increases.

Conclusion: An 18-month CHSM-based school-based intervention appears to be effective in increasing physical activity among elementary and middle school children.