Increasing evidence supports the multiple benefits to physical, psychological and social wellbeing, of green physical activity, a topic of increasing interest in the past decade. Evidence has revealed a synergistic benefit of green physical activity, which includes all aspects of exercise and physical activity in the presence of nature.Our theoretical analysis suggests that there are three distinct levels of engagement in green physical activity, with each level reported to have a positive effect on human behaviours. However, the extent to each level of green physical activity benefits health and wellbeing is assumed to differ and requires confirmation in future research. This elucidation of understanding is needed because previous literature has tended to focus on recording empirical evidence, rather than developing a sound theoretical framework to understand green physical activity effects. Here we propose an Ecological Dynamics rationale to explain how and why green physical activity might influence health and wellbeing of different population groups. This framework suggests that there are a number of unexplored constraints related to types of environment and population groups which shape reported levels of benefit of green physical activity. Further analysis is needed to clarify the explicit relationship between green physical activity and health and wellbeing, including levels of engagement, types of environmental constraints, levels of physical activity, adventure effects, skill levels and sampling of different populations.
Key points Previous literature has typically undertaken an operational analysis of the benefits of physical activity undertaken in nature and future work needs to understand how and why green physical activity might influence health and wellbeing with a multidisciplinary rationale. Further investigation of interacting constraints on green physical activity effects is needed, including levels of engagement, types of environment, level of physical activity, adventure, skill levels and groups. An Ecological Dynamics framework has the potential to provide principles for the design of green physical activity programmes as well as experiments on this topic.3