The studies of human and environment interactions usually consider the extremes of environment on individuals or how humans affect the environment. It is well known that physical activity improves both physiological and psychological well-being, but further evidence is required to ascertain how different environments influence and shape health. This review considers the declining levels of physical activity, particularly in the Western world, and how the environment may help motivate and facilitate physical activity. It also addresses the additional physiological and mental health benefits that appear to occur when exercise is performed in an outdoor environment. However, people’s connectedness to nature appears to be changing and this has important implications as to how humans are now interacting with nature. Barriers exist, and it is important that these are considered when discussing how to make exercise in the outdoors accessible and beneficial for all. The synergistic combination of exercise and exposure to nature and thus the ‘great outdoors’ could be used as a powerful tool to help fight the growing incidence of both physical inactivity and non-communicable disease.

A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor.

There is an urgent global need for accessible and cost-effective pro-mental health infrastructure. Public green spaces were officially designated in the 19th century, informed by a belief that they might provide health benefits. We outline modern research evidence that greenspace can play a pivotal role in population-level mental health.

Aims: This study evaluated two existing group-based health promotion initiatives (a social club and a swimming group) and compared these to a new green exercise programme (weekly countryside and urban park walks). Methods: Participants represented a clinical population (N = 53) and were all experiencing a range of mental health problems. They only attended one of the three programmes and sessions were held once a week for six weeks in all initiatives. Composite questionnaires incorporating two standardized measures to analyse changes in self-esteem and mood were completed before and after all sessions. Results: A significant main effect for self-esteem and mood pre and post activity (p < 0.001) was reported after participating in a single session. The change in self-esteem was significantly greater in the green exercise group compared with the social activities club (p < 0.001). Dose responses showed that both self-esteem and mood levels improved over the six-week period and improvements were related to attendance in the green exercise group. Conclusions: Green exercise as a health-promoting initiative for people experiencing mental ill health is equally as effective as existing programmes. Combining exercise, nature and social components in future initiatives may play a key role in managing and supporting recovery from mental ill health, suggesting a potential ‘green’ approach to mental healthcare and promotion.