Study Links Air Pollution on Race Day to Slower Marathon Times

Air pollution on the day of a marathon may be slowing runners down, according to new research that found higher levels of nitrogen dioxide were linked to slower race times.

The study found the association was especially pronounced among non-professional runners, suggesting that recreational and amateur participants may be more affected by air quality conditions than elite athletes, who often have more resources for training and race-day preparation.

Pollution and Performance

Nitrogen dioxide is a common urban air pollutant, largely produced by vehicle emissions, and has previously been linked to a range of respiratory and cardiovascular health effects. The new findings add athletic performance to the list of ways that elevated pollution levels can affect people engaging in sustained physical exertion outdoors.

Marathon organizers and runners alike have increasingly paid attention to environmental conditions such as heat and humidity when planning for race day, and researchers suggest air quality may deserve similar consideration, particularly in cities where pollution levels can vary significantly day to day.

The findings point to a potential factor race organizers could consider when scheduling events or advising participants, especially in urban marathons where traffic-related pollution is more likely to fluctuate.