Context matters: A review of reviews examining the effects of contextual factors in physical activity interventions on mental health and wellbeing

Physical activity (PA) is an effective and evidence-based intervention for the promotion of mental health, and prevention and treatment of mental health problems. However, little is known regarding the impact of contextual factors that may optimise the mental health benefits of PA. Contextual factors are the qualitative characteristics of PA that include its type, domain, physical and social environment, and delivery. We conducted an umbrella review of existing systematic reviews and meta-analyses of randomised controlled trials that evaluated the effect of contextual factors of PA on mental health outcomes. A total of 42 reviews were included, and covered the delivery (n = 8), social environment (n = 6), physical environment (n = 7), and type of PA (n = 33). There were no meta-analyses of randomised controlled trials pertaining to the domain of PA. Evidence showed beneficial effects for supervised PA (delivery), PA undertaken inside or outside (physical environment), PA undertaken individually or in groups (social environment), and many types of PA including aerobic and resistance training. This suggests that variations in contextual factors may play a role in enhancing the MH benefits of PA. However, few direct comparisons, and heterogenous control groups, precluded meaningful comparisons across and within contextual factors. Further, greater attention needs to be paid to the systematic testing and reporting of the contextual factors of PA to optimise mental health and wellbeing(PROSPERO registration: BLINDED FOR REVIEW).