Physical activity interventions for the promotion of mental health outcomes in at-risk children and adolescents: a systematic review.

Many young people are exposed to risk factors that increase their risk of mental illness. Physical activity provision is an increasingly popular approach to protect against mental illness in the face of these risk factors. We examined the effectiveness of physical activity interventions for the promotion of mental health outcomes in at-risk children and adolescents. We searched health databases for randomised and non-randomised intervention studies, with no date restriction, and assessed risk of bias using the Cochrane Risk of Bias tools. We present a narrative synthesis of our results accompanied with a summary of available effect sizes. Thirty-seven reports on 36 studies were included, with multi-sport or yoga interventions the most popular intervention approaches (a combined 50% of included studies). Outcomes measured included internalising, self-evaluative, wellbeing, overall symptomatology, resilience, externalising, and trauma outcomes. We found that 63% of between-groups effects favoured the intervention arm, and 83% of within-groups effects favoured an intervention effect. While recognising high risk of bias, our findings provide evidence in support of the effectiveness of physical activity interventions for promoting mental health outcomes in at-risk young people. We encourage further work designed to better understand the intervention characteristics that may lead to positive benefits.