Regular physical activity protects long-term health even in polluted air, but pollution can blunt the size of the benefit. Timing and placing exercise to avoid pollution peaks helps preserve it.
General
A meta-analysis covering 1.5 million adults found meeting recommended physical-activity levels cut all-cause mortality risk by about 30% where PM2.5 was below 25 µg/m³, but only by 12–15% at higher pollution levels — exercise stayed beneficial, with air quality shaping the size of the benefit (Ku et al., 2025).
