Introduction: This study assessed short-term and long-term effects of a 3-yr controlled school-based physical activity (PA) intervention on fatness, cardiorespiratory fitness (V˙O2peak) and CVD risk factors in children.
Methods: The study involved 18 schools (10 intervention and 8 controls) and included a follow-up 4 yr after the end of intervention. The analyses included 696, 6- to 7-yr-old children at baseline, 612 postintervention (age 9.5 yr) and 441 at follow-up (age 13.4 yr). The intervention consisted of a doubling of the amount of physical education (PE; from 90 to 180 min·wk−1), training of PE teachers, and upgrading of PE and playing facilities. Anthropometrics and systolic blood pressure (SBP) were measured. V˙O2peak was directly measured, and PA was assessed using accelerometry. Fasting blood samples were analyzed for CVD risk factors. A composite risk score was computed from z-scores of SBP, triglycerides, total cholesterol-to-HDL cholesterol ratio, homeostatic model assessment (HOMA score), skinfolds, and inverse V˙O2peak.
Results: The HOMA score of the intervention group boys had a smaller increase from baseline to postintervention compared with control boys (P = 0.004). From baseline to follow-up intervention group boys had a smaller increase in SBP compared with control boys (P = 0.010). There were no other significant differences between groups.
Conclusions: This 3-yr school-based PA intervention caused positive changes in SBP and HOMA score in boys but not in girls, and no effects were seen in PA, V˙O2peak, fatness, and the other measured CVD risk factors. Our results indicate that a doubling of PE and providing training and equipment may not be sufficient to induce major improvements in CVD risk factors in a normal population.
1Centre of Research in Childhood Health, Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense M, DENMARK; 2Unit of Clinical Physiology and Nuclear Medicine, Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, SWEDEN; 3Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, NORWAY; and 4Department of Exercise and Sport Science, University of North Carolina, Fetzer Gym, Chapel Hill, NC, USA
Address for correspondence: Anna Bugge, M.Sc., Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark; E-mail: firstname.lastname@example.org.
Submitted for publication April 2011.
Accepted for publication January 2012.