Impact of air pollution on running performance.

Air pollution exposures during training may impact race preformances. 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, 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 exposure (10.0 versus 5.0 μg/m) and ozone exposure (54.9 versus 36.9 ppm), respectively. Exposure measured by the two-pollutant threshold (PM and ozone) AQI was not significantly associated with race time; however, the association for summed two-pollutant AQI (PM 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.