Those slated to run the Los Angeles marathon in a few weeks will pray for cool temperatures, no rain and clean, clear skies. Women especially should hope for a smog-free day, since air pollution may affect their performance more than men, according to a new study.
The study, published in the March issue of the journal Medicine & Science in Sports & Exercise, looked at data on weather and air pollution as well as results of the top three male and female finishers from seven marathons in different cities (including L.A.) over eight to 28 years.
Researchers found that higher levels of particulates in the air were linked with slower performance times for women. Men's times did not change substantially.
The authors point out that marathoners in general may be more susceptible to pollutants, since they're operating at 70% maximum oxygen intake for about three hours (the average running time) and breathing as much air as a sedentary does person over two days. Also, breathing by mouth and breathing more and harder can carry particles deeper into the lungs.
Women may be more susceptible to pollutants than men because of an increased breathing rate and higher levels of particles deposited in the lungs.
"Athough pollution levels in these marathons rarely exceeded national standards for air quality, performance was still affected," Linsey Marr, the study's lead author and a researcher at Virginia Tech, said in a news release.
Runners do benefit, the paper notes, from the fact that most marathons take place on weekends and start in the morning, when pollution levels are lower.
Photo credit: Nick Ut / Associated Press