Effects of a school-based physical activity intervention on cardiometabolic health 5 years after cessation

While there have been several school-based physical activity (PA) interventions targeting improvement in cardiovascular disease (CVD) risk factors, few have assessed long-term effects. The aim of this paper was therefore to determine intervention effects on CVD risk factors 5 years after cessation.

Two schools were assigned to intervention (n = 125) or control (n = 134). The intervention school offered 210 min/week more PA than the control school over two consecutive years (fourth and fifth grades). Follow-up assessment was conducted 5-year post-intervention (10th grade) where 180-210 (73%-85%) children provided valid data. Outcomes were CVD risk factors: triglyceride, total-to-high-density-lipoprotein-cholesterol ratio (TC:HDL ratio), insulin resistance, blood pressure (BP), waist circumference, and cardiorespiratory fitness (VO_2peak ). Variables were analyzed individually and as a composite score through linear mixed models, including random intercepts for children.

Analyses revealed significant sustained 5-year intervention effects for HDL (effect sizes [ES] = 0.22), diastolic BP (ES = 0.48), VO_2peak (ES = 0.29), and composite risk score (ES = 0.38). These effects were similar to the immediate results following the intervention. In contrast, while TC:HDL ratio initially decreased post-intervention (ES = 0.27), this decrease was not maintained at 5-year follow-up (ES = 0.09), whereas WC was initially unchanged post-intervention (ES = 0.02), but decreased at 5-year follow-up (ES = 0.44).

The significant effects of a 2-year school-based PA intervention remained for CVD risk factors 5 years after cessation of the intervention. As cardiometabolic health can be maintained long-term after school-based PA, this paper demonstrates the sustainability and potential of schools in the primary prevention of future CVD risk in children.