Impact of air pollution on running performance

Air pollution exposures during training may impact race performances. We aggregated data on 334 collegiate male track & field athletes from 46 universities across the United States over 2010–2014. Using distributed lag non-linear models, we analyzed the relationship between race time and PM 2.5 , ozone, and two versions of the Air Quality Index (AQI) exposures up to 21 days prior to the race. We observed a 12.8 (95% CI: 1.3, 24.2) second and 11.5 (95% CI: 0.8, 22.1) second increase in race times from 21 days of PM 2.5 exposure (10.0 versus 5.0 μg/m 3 ) and ozone exposure (54.9 versus 36.9 ppm), respectively. Exposure measured by the two-pollutant threshold (PM 2.5 and ozone) AQI was not significantly associated with race time; however, the association for summed two-pollutant AQI (PM 2.5 plus ozone) was similar to associations observed for the individual pollutants (12.4, 95% CI: 1.8, 23.0 s). Training and competing at elevated air pollution levels, even at exposures within AQI’s good-to-moderate classifications, was associated with slower race times. This work provides an initial characterization of the effect of air pollution on running performance and a justification for why coaches should consider approaches to reduce air pollution exposures while training.