Wearing a mask doesn't significantly impair your oxygen intake or lung function, even during an intense workout, according to a new study.
There may be a subjective perception that it's harder to breathe in a mask, since it can cause a slight resistance and increases in humidity, warm air, and carbon dioxide.
But unless you have a serious lung or heart disease, there's no evidence wearing a mask functionally affects your ability to exercise, researchers found.
There's more proof that wearing a mask does not lower your oxygen levels, even if you're in the middle of a hard workout.
Although it may be sweaty or uncomfortable, masks don't interfere with lung function or oxygen intake in any meaningful way for healthy people, according to new research published in the Annals of the American Thoracic Society.
While some people have complained online or to their doctors that they felt they couldn't breathe in masks, the study found that's all down to perception.
Researchers from several universities reviewed more than 70 published studies related to the effects of various masks on breathing during physical activity.
They found no evidence that cloth masks and surgical masks significantly disrupt a person's lung function or reduce oxygen levels, even during exercise. Furthermore, there are documented cases of people habitually wearing masks for high-intensity exercise without any apparent ill effects — for instance, athletes who train in elevation masks, which are specifically designed to stress the respiratory system, are still safe to use.
"There might be a perceived greater effort with activity, but the effects of wearing a mask on the work of breathing, on gases like oxygen and CO2 in blood or other physiological parameters are small, often too small to be detected," Dr. Susan Hopkins, first author of the study and a professor of medicine and radiology at University of California San Diego School of Medicine, said in a press release.
Respirators are the most uncomfortable to work out in, but they won't harm you
The researchers even found masks with higher protection and filtering rates such as N95 respirators don't present a danger to people working out.
It's likely to be much more uncomfortable than a cloth mask, and that feeling of discomfort could affect your performance.
However, the UC San Diego team found that, while the perceived rate of effort was higher when wearing these masks, there was no evidence of damaging effects to heart and lung function, blood flow to the brain, or blood oxygen levels.
People with severe lung disease should talk to a doctor before exercising in a mask
Healthy people, regardless of age or gender, are able to wear masks during exercise with only minor effects on breathing function and oxygen levels, the study found.
However, masks were found to cause small changes to air resistance that could be an issue for people with severe cardiopulmonary diseases. For those people, the discomfort of a mask might be enough to impair their ability to exercise.
According to Hopkins, this population is also at greater risk of COVID-19, making preventative measures even more important. In those cases, she said, it may be best to talk to a doctor.
You may feel out of breath, but experts say it gets easier over time
Researchers acknowledged that many people perceive breathing to be harder while wearing one, but said it really is nothing more than a feeling.
"Wearing a face mask can be uncomfortable," Hopkins said. "There can be tiny increases in breathing resistance. You may re-inhale warmer, slightly enriched CO2 air. And if you're exercising, the mask can cause your face to become hot and sweaty. But these are sensory perceptions."
Even the experts have said they find masks to be somewhat inconvenient during a workout.
"Masks are very helpful but a lot of people don't like wearing them, and I don't like wearing them so I get that," Dr. Linsey Marr, an athlete and a world-renowned expert on aerosol transmission at Virginia Tech, told Insider.
The tradeoff, though, is reducing your risk of COVID-19, particularly when social distancing and good ventilation aren't feasible. And, with a little practice, the discomfort of wearing a mask during exercise subsides a bit.
"After a couple of days, you can used to it and it's fine," Marr said.
Read the original article on Insider