How Air Pollution Affects Runners

How much bad stuff are you breathing in when you run in busy areas?

Pollution Problems

Picture this: It’s a perfect, crisp morning  just right for a run. So you head out on the road and feel amazing—but you’re also sucking exhaust from the rush-hour traffic crawling by you. Would you be better off staying home? Not quite. While experts agree that air pollution can cause health problems, skipping your run because of poor air quality is never ideal. Here’s all about what’s up in the air—and what you can do about it.

The Dirt On Dirty Air

What, exactly, is hitting your lungs when you go for a run? “Air pollution is like a recipe that varies by location, weather, season and time of day,” says Michael Koehle, the head of University of British Columbia’s Environmental Physiology Lab and a leading expert on exercise and air pollution. “The recipe includes a mixture of various gases, like carbon monoxide or smog, and particles like dust and pollen.” Not to mention some of these particles are less than 1/30 the width of a human hair, making it easy for them to lodge deep inside your lungs.

Diesel exhaust, for example, can trigger asthma. Other pollutants, like ozone (a key component of smog), can be harmful to the cardiovascular system and can even cause cancer. “The lungs are taking the air we breathe and transferring it on to our blood cells, which immediately goes to the heart to be pumped to the rest of the body,” says Jason Way, a naturopathic doctor in the San Francisco area. “Over a prolonged period of time, smog can decrease your ability to run at your full capacity.”

Run Early And Often

That’s not to say you stick to indoor treadmill runs forever-more. Koehle says it’s key to be uber aware of when—and where—you run outside to be sure you’re breathing in the best air (see “Breathe Easier” below for more tips). “Pollution levels are higher during rush hour and in the heat of the day, so it’s better to go out early or in the late evening,” Koehle says. Even better if you’re only on a busy road for a portion of your run, since pollution drops significantly once you’re as little as 200 yards away from the congestion. 

Keep Moving

Above all, Koehle and other experts stress that while the risks of air pollution are definitely there, it’s far better to work up a sweat outside than not at all. In fact, recent studies show that the benefits of exercise outweigh the negative effects of air pollution. “To put it simply, air pollution is bad for your health,” Koehle says. “But being sedentary is even worse.”

Breathe Easier

Four Ways To Minimize Your Exposure To Air Pollution

  1. Quality check. Head to to check the outdoor air quality index (AQI) in your area before you head out. If the AQI measures more than 150 (100 if you have asthma or other breathing issues), hit the gym or be extra alert for any symptoms like shortness of breath, coughing or throat irritation while you run.
  2. Time it right. The sun’s energy triggers ground-level ozone, so run first thing if you can. Not a morning person? An evening run is always more optimal than hitting the pavement in the middle of the afternoon.
  3. Go green. Some studies show that you may breathe in 100 times more pollutants running within a mile of the highway than you would in a more rural area. Avoid congested areas if you can, and run in a park or a quieter neighborhood with tree coverage whenever possible.
  4. Eat right. Loading up on foods rich in antioxidants can help your body eliminate toxins picked up from pollution, Way says. Try sticking to leafy greens, broccoli, tomatoes, bell peppers, oranges, berries, nuts and seeds.

What about a mask?

While running with a surgical mask may seem like an obvious barrier to breathing in bad air, Koehle says there’s no research backing its benefits. “Wearing a mask may provide a false sense of security, so we do not recommend them at this time,” he says.