Promoting Physical Activity in Middle School Girls: Trial of Activity for Adolescent Girls
Background
Physical activity is important for weight control and good health; however, activity levels decline in the adolescent years, particularly in girls.
Design
Group randomized controlled trial.
Setting/participants
Middle school girls with English-speaking skills and no conditions to prevent participation in physical activity in 36 schools in six geographically diverse areas of the United States. Random, cross-sectional samples were drawn within schools: 6th graders in 2003 (n=1721) and 8th graders in 2005 (n=3504) and 2006 (n=3502).
Intervention
A 2-year study-directed intervention (fall 2003 to spring 2005) targeted schools, community agencies, and girls to increase opportunities, support, and incentives for increased physical activity. Components included programs linking schools and community agencies, physical education, health education, and social marketing. A third-year intervention used school and community personnel to direct intervention activities.
Main outcome measures
The primary outcome, daily MET-weighted minutes of moderate-to-vigorous physical activity (MET-weighted MVPA), was assessed using accelerometry. Percent body fat was assessed using anthropometry.
Results
After the staff-directed intervention (pre-stated primary outcome), there were no differences (mean=−0.4, 95% CI=−8.2 to 7.4) in adjusted MET-weighted MVPA between 8th-grade girls in schools assigned to intervention or control. Following the Program Champion–directed intervention, girls in intervention schools were more physically active than girls in control schools (mean difference 10.9 MET-weighted minutes of MVPA, 95% CI=0.52–21.2). This difference is about 1.6 minutes of daily MVPA or 80 kcal per week. There were no differences in fitness or percent body fat at either 8th-grade timepoint.
Conclusion
A school-based, community-linked intervention modestly improved physical activity in girls.
aDepartment of Biostatistics, Tulane University, New Orleans, Louisiana
bDepartment of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
cDepartment of Nutrition and Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
dDivision of Epidemiology, University of Minnesota, Minneapolis, Minnesota
eDivision of Epidemiology, The Ohio State University, Columbus, Ohio
fDivision of Prevention and Population Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland
gDepartment of Kinesiology, University of Maryland, College Park, Maryland
hGraduate School of Public Health, San Diego State University, San Diego, California
iDepartment of Physiology, University of Arizona, Tucson, Arizona
jDepartment of Exercise Science, University of South Carolina, Columbia, South Carolina
Address correspondence and reprint requests to: Larry S. Webber, PhD, Department of Biostatistics—SL18, Tulane University, School of Public Health and Tropical Medicine, 1440 Canal Street, New Orleans LA 70112.
The full text of this article is available via AJPMOnline at www.ajpm-online.net; 1 unit of Category-1 CME credit is also available, with details on the website.
ABSTRACT