Teun Remmers

Playability of school environments and afterschool PA | 117 As data collection was conducted in autumn, our results may not be comparable with other studies that usually perform their PA measurements in spring. Future studies are therefore encouraged to replicate this methodology in spring (or expressly study modification by season). In addition, one-third of the children in our sample experienced one hour earlier sunset due to daylight savings time change in fall. Similarly to the results of Goodman et al (44), we found that children measured in the period with earlier sunsets were less active, both in LPA and MVPA, independent of other meteorological measures (results not shown). In addition, differences in children’s PA were especially noticeable in the evenings (data not shown). Because of the relatively unequal distribution of participants measured during daylight saving time versus standard time and our limited sample size, we were unable to check whether the association between playability and ASPA differed between children measured with daylight saving periods versus standard time. Impact We found playability to be related with ASPA only in the time-period directly after-school, especially in children who live within 800 meters distance from their school. First, this showed that children who lived further away from school, were relatively confined to their own residential neighborhood after-school, thus making limited use of the school- environment for ASPA. Second, playgrounds in school-environments only had a limited influence on children’s ASPA throughout the day, and competing PA-domains (e.g. sports participation) may have explained variability in especially MVPA percentages in later time- periods of the day. Conclusion This study demonstrated the importance of playability of school-environments as an environmental determinant of after-school PA in children. With time and space filtering, the conceptual understanding of ASPA and its association with the physical environment can be improved. This may help to develop more tailored interventions to promote specific PA-domains at specific time-periods during the day. All in all, our analytical design with time and space filtering may encourage researchers to look into more domain- specific parts of children’s PA behavior within the opportunities and limitations of their own sample, embedded in strong theoretical foundations. Acknowledgement We are grateful to the children and schools participating in this study. This study was funded by the Netherlands Organization for Health Research and Development (ZonMW), project number 200130003. All authors declare they have no competing interest.