To increase physical activity levels in children, knowledge on how school playgrounds can be optimally designed is important. Until now, the contribution of playground variety and greening to children's physical activity level during recess remains unclear. This study examined the associations of school playground variety and greening with energy expenditure (EE) in elementary school children in Ecuador and Belgium. Additionally, moderating effects of study site and gender were studied. Observational data were collected using SOPLAY in ten schools in East Flanders (Belgium) and Cuenca (Ecuador). Data were analysed with linear mixed-effects model analyses. Results showed that independent of study site, EE was higher in playground areas with less green elements, and a higher level of total variety. Primary surface was only associated with EE in boys, they were more active when an artificial surface was present. Implementation of loose equipment was somewhat more strongly positively associated with EE in Ecuadorian than in Belgian children. Because of the well-known restorative effects of green elements, we do not wish to suggest that less greening should be implemented at schools. However, ideally green spaces should be designed in a way that active play is stimulated by combining green elements with other improvements.
Keywords: Physical activity; SOPLAY; elementary school; energy expenditure; greening; variety.