Up for Debate: Does Regular Physical Activity Really Improve Mental Health?

Abstract: Physical activity is frequently touted as beneficial for mental health. This paper, based on a 2023 ACSM colloquium, highlights key strengths and limitations of the evidence regarding physical activity and mental health from three perspectives: epidemiological studies, randomized controlled trial experiments, and investigations that explicitly consider the potential role that contextual factors, such as the social climate in which physical activity is completed, can play in physical activity-mental health interactions. A large body of epidemiological evidence supports that regular leisure time physical activity is associated with less depression and anxiety. Higher amounts of physical activity are often associated with fewer depressive symptoms, but there may be a dose-response point where for some people more is not better but can plateau or even worsen. Epidemiological evidence is emerging but currently inadequate to support associations between mental health and occupational, transportation/active commuting or domestic/household physical activity types. A large body of randomized controlled trials, typically small, short duration and conducted with samples biased toward middle-to-higher socioeconomic status Whites, supports that the adoption of regular exercise improves aspects of mental health; however, the mechanisms are unclear and for those without mental disorders the mean effects are small. Mental health benefits of exercise may be partially a placebo response or result from contextual factors surrounding exercise. A small body of evidence supports that contextual elements, such as the program implementation quality and social environment, can influence the mental health outcomes associated with physical activity programs, but the evidence is currently inadequate to identify which contextual variables have consistent moderate or larger effects. Greater progress will be made in this area when research designs are expanded to include consideration of the potential influence of contextual factors on relationships between physical activity and mental health.