Running for some is an “Essential Personal Activity,” to quote the section of the Mayor of Philadelphia’s Stay at Home Order that permits such activities. I was a long-time runner before the Order and I have continued to run throughout its duration. Eleven days after the Order became effective, the CDC recommended the following: “Wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies) especially in areas of significant community-based transmission.” Soon I saw a couple of people running with a mask, then a few people, then several, and I have gradually seen their numbers increase by the week.

Are there people who should not be running with a mask?

The Physical Activity Guidelines for Americans recommend a specific volume of work, done at a particular intensity, for the people seeking to attain the most health benefits through exercise. The words “specific” and “particular” will necessarily have different meanings for different people.

My particular speed is a faster-than-average speed. My breathing rate almost immediately increases at the start of most runs and continues to increase several minutes after that. The rate continues to increase, often increasing all the way to the end of the run, when my breathing can be loud to anyone nearby.

First-hand experience has taught me that wearing a cloth face covering can make me lightheaded.

That experience is why the CDC says that anyone who has trouble breathing should not wear a mask. The World Health Organization is explicit. Using all-caps for emphasis, they say that people should not wear masks while exercising because masks can make it difficult to breathe.

Writers have quoted fitness professionals and scientists saying that all people should be running with a mask. They seem to be ignoring the people who have trouble breathing when running. “Trouble breathing” means that they can barely speak a few words, if any, before needing to take a breath.

I competed in track and field and cross country for about 25 years. I earned many awards and I spent some of those years training with and competing against some of history’s best runners. I have coached collegiate, Olympic-hopeful, and professional athletes for 20 years. At Run Shoe Store, I have been selling technical running shoes for 11 years. At The Training Station Gym, I have been consulting and training amateur runners for 10 years.

I have seen the diversity of people who run.

Many are not runners who have been running with some regularity for years. They are not folks that consider themselves ‘runners.’

They are very often novices who were inactive and who took up running to lose weight. Their numbers—approximately 17 million people—equal about 40% of all runners. (The most recent data is available for purchase here but you can see an older version of the report here.)

Slow jogging is hard for them. They immediately start breathing hard and the breathing rate increases throughout the run. They have trouble breathing the whole time, regardless of how slowly they run.

Asking novices to wear a mask is tantamount to asking them to ignore the guidance of the CDC. Just as serious, that expectation will have an outcome for them that it doesn’t have for others who run.

Why wearing a mask can have an adverse impact on some people

When running with a mask is dangerous for folks but they feel social pressure to wear a mask, some of them will simply stop running. In my experience, previously inactive people who stop running also stop exercising because running was their only exercise. (A point also suggested near the beginning of this study.) Strong evidence demonstrates that inactivity increases mortality.

These people are being told to do something that may increase their inactivity—and hence their mortality—in the name of lowering mortality from COVID-19!

Few runners, if any, like running with a mask because it makes breathing harder than usual. Some can handle it because they don’t have trouble breathing or can slow down so that they are not having trouble.

There are runners who can’t do that. They are always having trouble breathing and they are already running as slow as they can. They should not add a mask to that situation. But they can and should do things to help keep others safe.

Even without a mask, runners can help in the fight

The pandemic compels us all to help prevent the spread of infection. That’s why I try to avoid people by starting runs before 8 AM and I run loops around a city block with few if any pedestrians.

So long as they keep to that basic strategy—keeping a distance of 6 feet from others—people who run outside without a mask are joined in the effort to maintain social distancing.

All of us have been instructed to distance ourselves so as to avoid the droplets from coughing, sneezing, and talking. The droplets are believed to be the main way that the virus leaves one person and gets into the body of another person.

With that in mind, here’s a list of things to avoid if you are not running with a mask and are nearby others:

  • Don’t sneeze
  • Don’t cough
  • Don’t talk
  • Don’t blow snot out of the nose
  • Don’t spit

There are millions of novice runners who have trouble breathing while running (as do asthmatics, heavy runners, and fast runners). When that’s the case, they should follow the CDC and not wear masks.