When COVID-19 forced local gyms to close until further notice, we all had to figure out other ways to get in our daily exercise. For many, this meant getting outside for a long walk or a run. But while hitting the pavement and enjoying the outdoors should be great for your health, high levels of air pollution outdoors may make things more complicated.
The American Lung Association’s 2021 "State of the Air" report found that more than four in ten Americans, or over 135 million people, are living in places with unhealthy levels of ozone or particle pollution. Decades of scientific research has documented the dangerous health impacts of these pollutants. Recent studies have dug into the specific impacts of exposure to air pollution while exercising outdoors.
Recently, the European Heart Journal published a study about the trade-off between the health benefits of physical activity and the harmful effects of air pollution while performing that activity outside. The study specifically focused on how young adults ages 20-39, a group that is typically in optimal health, are affected by particle pollution. As you may have suspected, it was found that participants who lived in places with low-to-moderate air pollution decreased their risk of cardiovascular disease the more they exercised. However, participants who were exposed to high average levels of air pollution while exercising were adversely affected, suggesting that the health risks from exposure to particle pollution outweighed the health benefits of exercising. It should be noted that the level of intensity also played a factor in these results, with low intensity fitness being a better option for times when air pollution is high.
Another study released a few years ago found that marathon runners run slower in more polluted areas. Scientists at Southwestern University of Finance and Economics in Chengdu, China analyzed the performances of over 300,000 marathon runners of 56 races in China between 2014 and 2015. They compared finish times with the daily air quality index (AQI), a number that is calculated by measuring the dangers of six major air pollutants daily and ranking them on a scale from 0 to 500. AQI scores greater than 100 indicate greater danger lurking in the air. The study concluded that every doubling of the AQI increases a runner’s finishing time by about 4%.
To put this into perspective, the best runner in their study ran a marathon in 2:18:21 in a city where the AQI was 105. That same runner would take 9.9 more minutes to cross the finish line at the Beijing Marathon, where the AQI climbed to 216 by the end of the event. In fact, this particular marathon made headline news back in 2014 for hazardous conditions that caused many runners to don masks. Further study suggests that not only are high levels of particle pollution harmful to runners’ times, but it may affect their respiratory tracts long-term as well.
So how do you protect yourself?
Check local conditions: Make a habit of checking your current air quality at airnow.gov. You can also easily get access to up-to-date AQI measurements on your local weather channel or weather app. Both sources will also issue warnings when the AQI is particularly bad so that you can avoid being outside as much as possible.
Carefully choose your route: Certain areas such as nature trails and park paths are usually lower in pollution than crowded city streets near highways or industrial areas. Avoiding high-traffic times of day is another way to decrease your likelihood of breathing in the air pollution released by scores of idling cars if you are running in an urban area.
Adjust your workout: Studies suggest that adjusting the intensity of your workout is an easy way to decrease the amount of unhealthy air that is inhaled. So, deciding to take a long walk instead of a short run is another way that you can still enjoy the outdoors and minimize the possible lung damage.
For more tips on how to protect yourself and your community from unhealthy air pollution, visit our “State of the Air” report.
Blog last updated: August 25, 2023