Well-being benefits of green exercise in healthy adults : systematic review and meta-analysis

Research shows that exercising in outdoor natural environments (green exercise) tends to promote higher well-being benefits than exercising in indoor environments; however, a meta-analysis of experimental studies is lacking. We conducted a systematic review and a meta-analysis comparing the mental well-being effects of exercising in green vs indoor environments. A total of 11 studies, from 2010 onwards, were collected. Qualitative analysis indicated greater psychological improvements of participants performing green exercise, comparing to those performing indoor exercise; however, there is a lack of methodological quality in most of the studies, and disparity in outcome measures. To aggregate more data from a broader time-span, a meta-analysis was performed in a pool of studies from the previously mentioned systematic review, plus nine other studies from a systematic review published by Coon et al., in 2011. Outcome measures included in the meta-analysis were related with affect and perceived exertion. Green exercise showed higher improvement in affect, and lower perceived exertion when compared to indoor exercise. This systematic review and meta-analysis highlighted the need for more experimental studies on this topic. Results were consistent with previous evidence, and should be considered by health professionals and policy makers, to promote a more active lifestyle in increasingly sedentary populations of developed countries