The aim of the current study was to examine the effectiveness of a school-centered multicomponent PA intervention, called ‘Active Living’, on children's daily PA levels.

A quasi-experimental design was used including 9 intervention schools and 9 matched control schools located in the Netherlands. The baseline measurement took place between March–June 2013, and follow-up measurements were conducted 12 months afterwards. Accelerometer (ActiGraph, GT3X +) data of 520 children aged 8–11 years were collected and supplemented with demographics and weather conditions data. Implementation magnitude of the interventions was measured by keeping logbooks on the number of implemented physical environmental interventions (PEIs) and social environmental interventions (SEIs). Multilevel multivariate linear regression analyses were used to study changes in sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) between baseline and follow-up. Finally, effect sizes (ESs) were calculated using Cohen's d.

No pooled effects on PA and SB were found between children exposed and not exposed to Active Living after 12 months. However, children attending Active Living schools that implemented larger numbers of both PEIs and SEIs engaged in 15 more minutes of LPA per weekday at follow-up than children in the control condition (ES = 0.41; p < .05). Moreover, children attending these schools spent less time in SB at follow-up (ES = 0.33), although this effect was non-significant. No significant effects were found on MVPA.

A school-centered multicomponent PA intervention holds the potential to activate children, but a comprehensive set of intervention elements with a sufficient magnitude is necessary to achieve at least moderate effect sizes.