Associations between greenspace and moderate-to-vigorous physical activity and sedentary time in adolescents

Abstract This study explored the relationships between greenspace and adolescents’ moderate-to-vigorous physical activity (MVPA) and sedentary time, and whether the relationships were moderated by sociodemographic factors (sex, ethnicity, age and neighbourhood deprivation). Data from 325 adolescents (aged 13–18 years) who lived in Ōtepoti Dunedin, Aotearoa New Zealand from the BEATS Natural Experiment study were analysed. Individual levels (distance to the nearest greenspace and the amount of greenspace around home addresses) and area levels (greenspace accessibility) greenspace metrics were utilised. Participants’ MVPA and sedentary time were recorded by accelerometers. The Generalized Additive Model (GAM) was used to explore the potential non-linear relationships of interest. The findings showed nonlinear associations between distance to the nearest greenspace and adolescents’ MVPA and sedentary time, suggesting that greenspace located 500–700 m from residences is optimally placed for encouraging MVPA and reducing sedentary time in this age group. No relationships in amount of greenspace and greenspace accessibility were found with MVPA and sedentary time. Regarding moderation analyses, no moderators reached statistical significance, however, neighbourhood deprivation may have a potential tendency to moderate the association of interest (p < 0.10). Overall, the exploration for potential sociodemographic moderators and for optimal distance provides important evidence for future research on targeted environmental policies and equitable urban design strategies.