A Multicomponent Schoolyard Intervention Targeting Children's Recess Physical Activity and Sedentary Behavior: Effects After One Year.

Background Aim of the study was to test the 12-month effects of a multicomponent physical activity (PA) intervention at schoolyards on recess PA levels of 6th and 7th grade children in primary schools, combining Global Positioning System (GPS) and accelerometry data. Methods A quasi-experimental study design was used with 20 paired intervention and control schools. GPS confirmatory analyses were applied to validate attendance at schoolyards during recess. Data from 376 children from 7 pairs of schools were included in the final analyses. Pooled intervention effectiveness was tested by multilevel linear regression analyses, whereas effectiveness of intervention components was tested by multivariate linear regression analyses. Results Children exposed to the multicomponent intervention increased their time spent in light PA (+5.9%) during recess. No pooled effects on Moderate-to-Vigorous PA were found. In depth-analyses on intervention components showed that physical schoolyard interventions particularly predicted a decrease in time spent in sedentary behavior during recess at follow-up. Intervention intensity and school's commitment to the project strengthened this effect. Conclusions The multicomponent schoolyard PA intervention was effective in making children spend a larger proportion of recess time in light PA, which was most likely the result of a shift from sedentary behavior to light PA.