Conclusions
To summarise, outdoor natural environments may provide some of the best all-round health benefits by increasing physical activity levels with lower levels of perceived exertion, altering physiological functioning including stress reduction, restoring mental fatigue, and improving mood and self-esteem and perceived health. Thus, exercise within green spaces and the great outdoors may be a useful natural medicine (vis medicatrix naturae) [65] to address health challenges facing developed countries. Alongside the social aspect which some individuals crave, it may also increase enjoyment and adherence to bring about positive behaviour changes in a large proportion of the population.
The great outdoors, therefore, should not be just considered a playground for those who seek the thrills of extreme sports, but emphasis should be placed on access for all. One way of doing this is to ensure urban parks are maintained and are developed to produce interesting