A large body of research suggests that exercising outside in areas with high levels of air pollution can be damaging to the lungs and other aspects of human health as well.
For example, a review of global pollution studies from 2004 found that exercising outdoors, even when small amounts of air pollution are present, may be harmful to the lungs. And according to an overview of exercise and air pollution from The Huffington Post, there have been a handful of similar studies that point to the same or a similar conclusion.
However, more recently, new research is continuing to find that even though air pollution can be harmful to your health, exercise—even when performed outside—may actually protect you from those damaging effects.
The Huffington Post points to a 2012 study conducted on mice which found that long-term aerobic exercise may have helped to develop “protective effects” against lung inflammation caused by diesel exhaust particles.
And even more recently research from the University of Copenhagen published in the journal Environmental Health Perspectives concluded that in relation to premature mortality, the health benefits gained from exercising may be more important to our health than the negative effects associated with air pollution.
According to Science Daily, this was the first large population-based study to examine the combined effects of exercise and air pollution in relation to mortality. It analyzed data from 52,061 50- to 65-year-olds from the cities of Aarhus and Copenhagen who were a part of the larger study titled Diet, Cancer and Health.
The participants reported on their “physical leisure activities” (like sports, cycling to and from work, gardening and walking) from 1993 to 1997. 5,500 participants died before 2010, but the results showed that compared to those who didn’t exercise, there were 20 percent fewer deaths among the group that did exercise, even if they lived in the most polluted areas of the cities.
The researchers did note that this study only relates to Denmark or “sites with similar air pollution levels,” therefore, the results may not hold true for other areas of the world where air pollution levels are higher.
For comparison, the World Air Quality Index currently rates Copenhagen’s air quality level at “moderate” (“air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution”), whereas New York’s level is currently rated as “good” (“air quality is considered satisfactory, and air pollution poses little or no risk).
The takeaway: air pollution does pose a health risk (especially for those with asthma, diabetes and heart or lung conditions), but exercise, even when performed outside, may help to deter the negative side effects.
Plus, because we know that regular physical activity offers a significant amount of other important health benefits (and that outdoor exercise also offers its own slew of advantages) it shouldn’t be neglected due to concerns about air pollution.
Be proactive about making sure that it’s safe for you to exercise outside by reviewing current reports about your city’s air quality, timing your workouts appropriately and exercising indoors when necessary.