With the rapid spread of the omicron variant, mask mandates have once again returned to many gyms, along with this dilemma: Should gym goers wear a N95 or KN95 mask, which offer more protection than a cloth mask but can be uncomfortable?
Officials at the Centers for Disease Control and Prevention describe N95s and KN95s as offering the most protection - as long as they are not counterfeit - but stop short of suggesting people abandon fabric masks entirely, believing that wearing any mask is better than not wearing any one at all.
"I don't want to tell anyone not to wear an N95 to exercise," says Melanie McNeal, physical and occupational therapy manager in the Baylor College of Medicine's orthopedic surgery department. "Bring it. Wear it. But have another one in your bag, so when one gets sweaty or uncomfortable, you can replace it with one that's fresh and clean."
As the pandemic enters its third year, guidance on how to safely exercise, especially indoors, keeps changing along with the virus. Michele Maxson, 42, uses different masks for different workouts.
"When I'm exercising in close contact with people, I wear an N95 for protection," says Maxson, a Maryland public school math teacher living temporarily in Tokyo. "If the workout provides social distancing, or I am running outdoors, I stick to cloth for comfort. I have a double fabric one and bring more than one if it gets too wet. Neither is optimal, but these are the sacrifices we need to make right now to stay both safe - and fit - in a covid world."
It often seems like the perfect exercise mask just doesn't exist - at least not yet.
"The fabric masks get wet from perspiration. Sometimes they fall off if they are not snug," Maxson says. "KN95 masks stay on better but get super sweaty quickly and make it tough to breathe. Sometimes masks get sucked in when I inhale deeply, which makes my brain think that I'm limiting my oxygen intake."
McNeal cites several studies, however, that raise issues about N95 respirators and urges athletes to be aware of them. While effective at blocking the virus, they can make breathing difficult, according to a 2011 study by researchers in Singapore who measured nasal airflow and found that wearing an N95 restricted the amount of air expelled in a single breath, and also reduced the amount of filtered clean air taken in by the mask wearer. And a 2020 study by German scientists found that people wearing N95s felt as if their body temperature was increasing, although this was not the case.
"The increase in body temperature was more of a perception and not actually a fact," McNeal says. "As we know, though, perception is reality."
If athletes are nervous about infection, and still want to wear an N95, they should, McNeal says, as long as they know about the potential problems.
"They are more restrictive with breathing," she says. "Also, when you are exercising, they can cause you to feel as if your body temperature is rising, as if overheating. If you aren't used to exercise and this happens, take a quick break, take some deep breaths to calm your heart rate and let that feeling of being overheated pass until you feel comfortable resuming."
Athletes often must choose between a mask that's safer vs. one that's made of a more comfortable material, McNeal says. "Athletes should consider the environment they are working out in as well as the type and intensity of a workout when making this decision."
Most people don't need a mask when exercising outside, unless there are other people nearby, she says.
Mike Sheldon, 72, of Westfield, Mass., an avid outdoor runner, hangs a surgical mask under his chin when he goes out and pulls it up if he sees someone approaching. "It fogs up my glasses in cold weather," he says. "On the plus side, it keeps my face warm."
When indoors, masks made of multiple layers of a moisture-wicking material, such as polyester, are the most comfortable, McNeal says.
"The fit is important, and the material is important," she says. "You don't want material that will disintegrate when it gets wet. If you are doing cardio or CrossFit, where you are sweating profusely and your heart rate is going up, an N95 won't be comfortable. If you are doing bicep curls - a lightweight workout - and not sweating profusely, an N95 should be fine."
Bob Metzger, 70, a retired software developer who lives in Lakeville, Minn., learned this the hard way after open heart valve repair last May. His post-op rehab involved nearly three dozen one-hour cardio sessions of fast-paced walking on an indoor treadmill - mask required. He wore a face covering made of cotton, a fabric notorious for retaining moisture. "My mask would typically be soaked when I was done," Metzger says. "By the time my cool down was complete, it felt clammy and icky."
He's switching to an N95. But he remains attached to that cotton mask, made by his wife and featuring a cute ladybug design. He plans to wear it over the N95, "if only just for the smiles I get from people when they see it," he says.
Josiah Hester, assistant professor of computer engineering at Northwestern University - who recently led a team that invented a "FaceBit," a quarter-sized sensor that attaches to a mask and measures respiration and heart rates much like a "Fitbit" - predicts that masks, like other consumer products, will evolve over time to meet individuals' lifestyle needs, including exercise.
“We may start to see custom-designed masks and new materials that are more tuned to the requirements of exercising, for example, more breathable and less bulky KN95s, oversized air pockets, more conformable to your face, lighter, and less likely to move around with strenuous activity, sweat and rain resistant,” he says. “I’m sure this will be an explosion of products in the next few years. With [covid] becoming endemic, and two years of practice in the habit of wearing masks, I think for sure that we will have to adjust how we do everything from eating to exercise because of this new reality.”