Should You Wear a Mask While Running Outside?

Running is a great way to deal with stress, but running outside now comes with an added stress — do you need to wear a face mask or is it dangerous to cover your mouth and nose?

The answer to the first part of the question depends on what your city, country or state requires as well as your vaccination status. For instance, the Centers for Disease Control and Prevention (CDC) recently announced that Americans who are fully vaccinated against COVID-19 no longer need to wear a mask outdoors, unless they're in a crowded setting (like a 5K). Check out your state's and/or county's government website for up-to-date requirements.

Beyond that, consider where you're running — if your route is crowded and you can't maintain a social distance of at least 6 feet, a face mask is a smart choice, even if wearing it may be uncomfortable.

Viruses like COVID-19 spread through respiratory droplets created when someone who is infected coughs, sneezes or talks, according to the Centers for Disease Control and Prevention (CDC).

Those droplets can travel up to 6 feet — about the length of two arms — and be inhaled by or land in the mouths or noses of people close by. Because of this, the CDC recommends that people over age 2 wear a mask when you can't stay at least 6 feet away from other people.

"Fortunately, we know that COVID-19 is unlikely to be transmitted outside, especially if you are maintaining at least 6 feet of distance from those around you," says family physician Lisa Doggett, MD, MPH, of Austin, Texas, who is also a runner. "When I am running by myself and I am unlikely to come within 6 feet of others, I certainly do not wear a mask."

However, Dr. Doggett says she does mask up when she exercises in busier downtown Austin locations, even though it's not as comfortable. "I don't like wearing a mask, and it is difficult when I am breathing fast," she says. "But I think it is important to protect others in case I happen to be infected."

Social media posts have spread rumors that wearing a mask can lead to medical issues like hypoxemia, which the Cleveland Clinic defines as low oxygen levels in your blood; hypoxia, or low oxygen levels in your tissues; or hypercapnia, which refers to carbon dioxide build-up in the bloodstream. But don't believe everything you read on Instagram.

"There is no evidence or reason to be concerned about inhaling too much of your own breath or carbon dioxide while wearing a cloth or surgical mask while running," Dr. Doggett says. "Air exchange should be sufficient to avoid any problems."

In fact, a small March 2021 study of 12 people published in the ​European Respiratory Journal​ concluded that it was safe for healthy people to wear a face mask during intense exercise. Although participants experienced a reduction in their ability to perform aerobic exercise while wearing a mask, none of the effects posed any health risks.

Another small study — this time published in June 2021 in ​JAMA Open Network​ — confirmed these results with participants wearing N95 masks during peak exercise. Though VO2 and heart rate were lower at maximum effort, values remained within normal limits and posed no safety concerns.

And the World Health Organization (WHO) definitively states that prolonged use of medical masks — as long as they are used correctly — does not lead to carbon dioxide intoxication or oxygen deficiency. However, they do point out that wearing a mask during longer runs can make the mask sweaty and promote the growth of microorganisms.

Look for an exercise mask (there are ones specifically designed for the task) that's made from moisture-wicking fabric that's not too thick or restrictive, per the Cleveland Clinic.

Not only is a mask that's sweaty going to be less comfortable, but a wet mask is less effective at filtering viruses and other germs.

Even though there's no danger to wearing a mask, stay in tune with how your body feels during a run — wearing a mask may affect your performance and pace, sports medicine specialist Caitlin Lewis, MD, told the Cleveland Clinic. If you experience dizziness, chest pain or difficulty breathing, find a safe, socially distanced place to sit down, remove your mask and catch your breath.

Running with a face mask might take some time to adjust to, says CJ Hammond, CPT, a certified personal trainer with RSP Nutrition. He reassures runners that it's OK to slow down your pace when wearing a face mask. It's better to run at a slower pace while breathing properly than to compromise your running mechanics.

"Diaphragmatic breathing is a great skill set that needs to be practiced with using the mask," Hammond says. "The mask will restrict simple airflow. Breathing from your belly, so your ribs expand, will help you to pump oxygen-rich blood throughout the body at a faster pace."

Wash or disinfect your mask after every run. It's a good idea to have more than one mask, so you always have a clean mask available for exercising.

When you take off your mask after a run, the CDC recommends handling it only by the ear loops or ties and not touching your eyes, nose or mouth until you've washed your hands.