Study shows smog diminishes health benefits of outdoor workouts

People who jog, cycle, or engage in other forms of outdoor exercise may not receive the full health advantages if they do so in polluted urban areas, according to new research. The study indicates that pollution can reduce the positive effects of physical activity on lifespan and cancer risk.

The investigation analyzed health data from 1.5 million individuals across multiple countries. Researchers, including teams from University College London (UCL) and City University of Hong Kong, discovered that regular exercise provides fewer protective benefits for those living in regions with high air pollution levels.

The typical reduction in mortality risk from cancer and heart disease associated with running is significantly lowered when fine particulate matter in the air exceeds 25 micrograms per cubic meter. Experts say this finding could concern millions of outdoor fitness enthusiasts worldwide, as nearly half of the global population resides in areas with particulate concentrations at or above this threshold.

Andrew Steptoe of UCL commented that "polluted air can partially block the advantages of exercise, though it does not completely remove them," emphasizing the growing evidence of the harmful impact of fine particle pollution on health.

The study, published in BMC Medicine in November, notes that pollution levels in many urban areas surpass 35 micrograms per cubic meter, and in some cases can reach 50 or higher. At such levels, the health gains from outdoor workouts become noticeably less pronounced.

Nevertheless, Po-Wen Ku from National Chung Hsing University in Taiwan stressed that running outdoors "still offers benefits even in polluted settings," and that improvements in city air quality could further amplify the positive effects of exercise.

According to the World Health Organization, prolonged exposure to outdoor air pollution contributes to around 4 million premature deaths globally each year.

Author: Riley Thompson