The evidence consistently points in the direction that green environments are good for stress levels and physical activity. The stress-reducing effect is the best supported: multiple studies using direct measurements of heart rate and blood pressure point in the same direction. Walking more often or for longer is also realistically linked to proximity to green space. The evidence comes primarily from observational studies, however, so overclaiming is not appropriate, but neither is ignoring it.
Walking in nature and spending time in green environments are consistently associated with lower heart rate, lower blood pressure and lower perceived stress. A systematic review of measurements taken outside the laboratory1 describes this as the most compelling evidence that green spaces can reduce stress. More research is still needed to establish the precise magnitude and effective dose, but the association is consistent enough to speak of preliminary causal significance.
Green space in the residential environment is also associated with greater physical activity. An observational study based on the Health Survey for England2 found that residents in the greenest neighbourhoods were 27% more likely to meet physical activity guidelines than people in the least green neighbourhoods. Notably, this difference was not found in recreational use of green spaces, but in gardening, home maintenance and work-related activity. The explanation for the association is therefore not yet fully clear.
How far you live from green space makes a noticeable difference. A Dutch longitudinal study of more than 3,200 adults3 showed that people walked almost 23 minutes less per week for recreation for every 100 metres of additional distance to the nearest green area. For active commuting on foot or by bicycle, the association was weak or absent. This is a longitudinal analysis using a method that accounts for individual differences, which makes the association for walking relatively reliable.
For specific modifications to urban green space, the picture is mixed. A 2024 systematic review4 concluded that playgrounds and outdoor fitness equipment generally have a positive effect on physical activity, but that evidence for walking paths and general greening is less clear-cut. Research on mental health benefits is scarce: only two studies were available, of which one showed a positive effect for depression. The reviewers point to methodological limitations and the need for long-term studies.
Not every health effect of green space is equally well supported. A large American study of more than 157,000 postmenopausal women5 found no association between the amount of green space in the neighbourhood and the risk of falling. A Japanese cross-sectional study of 204 older adults6 did find that more green space in the neighbourhood was associated with more frequent sufficient walking, but only among older adults with low self-confidence in physical activity, and the effect was statistically small. Finally, a policy analysis7 highlights that not everyone has equal access to green space, and that unequal access is associated with greater health disparities between population groups.
Based on one systematic review (stress reduction), one systematic review (urban green space interventions), multiple observational studies (cohort, cross-sectional, survey analysis) and one commentary article. Total participant numbers vary; the largest dataset is the Women's Health Initiative with 157,583 participants. A causal relationship is plausible for stress reduction and recreational walking near green space; for the remaining outcomes the findings reflect associations.