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Exercise is often prescribed as a remedy for depression and anxiety, and millions are told to move more as a way to feel better. That advice is rooted in good science: physical activity can improve mood, reduce symptoms of depression and anxiety, and lower the risk of many chronic diseases. But individual exhortations to “just exercise” — or the framing of exercise as solely a matter of personal responsibility — misses a larger point. The benefits of regular physical activity are not equally available to everyone. Socioeconomic factors, community design, access to safe places to exercise, and time constraints shape whether people can translate advice into action.

If we take mental health seriously at a population level, policymakers and philanthropic organizations should treat exercise like a public-health priority and invest in the environments and programs that make it possible. That means funding safe parks, walking and biking infrastructure, school and workplace physical-activity programs, and community-based initiatives that reduce barriers for groups least likely to get sufficient exercise.

Charitable giving can play a catalytic role: supporting research on scalable interventions, underwriting community programs in under-resourced neighborhoods, and backing policy advocacy to make active living the default in city planning. Employers and insurers also have roles to play by covering preventive programs and creat