Air Pollution Tied to Diminished Benefits of Regular Exercise

THURSDAY, Dec. 11, 2025 (HealthDay News) -- Long-term exposure to polluted air can weaken the health benefits of regular exercise, according to a review published online Nov. 28 in BMC Medicine.Po-Wen Ku, Ph.D., from University College London, and colleagues conducted a systematic literature review to assess whether higher levels of fine particulate matter (PM2.5) reduce the protective effects of leisure-time physical activity (LTPA) on all-cause, cardiovascular, and cancer mortality. Based on seven cohort studies (1.5 million participants; 115,196 deaths), the researchers found that the reduction in all-cause mortality risk diminished with higher PM2.5 exposure. Meeting the recommended LTPA level (7.5 to 15 MET-hours/week) was associated with a 30 percent reduced all-cause mortality risk at PM2.5 25 μg/m3. Pooled data from three cohorts (869,038 individuals; 45,080 deaths) confirmed this pattern. Among individuals meeting the recommended LTPA level, there was a lower risk for all-cause mortality versus those in the highest-risk group (reference, 25 μg/m3 for all outcomes and became nonsignificant for cancer mortality at 35 to 50 μg/m3."Our findings emphasize that exercise remains beneficial even in polluted environments," Ku said in a statement. "However, improving air quality can greatly enhance these health gains."Abstract/Full Text.Sign up for our weekly HealthDay newsletter