During a pandemic, the same is true for wearing a mask.

However, since the start of Covid-19, there’s been debate over how safe it is to wear a mask while exercising — for both the person working out and the people near them. In December, the World Health Organization recommended people “not wear masks during vigorous” physical activity. The CDC, meanwhile, urges people to wear masks when exercising — even during a high-intensity workout. 

Now, a new study offers additional guidance. Scientists report in the European Respiratory Journal there are no adverse health effects associated with mask-wearing while exercising — although wearing a mask can slightly impair performance.

It may not be a good idea to run to your nearest open gym. Studies suggest gyms and other enclosed spaces are areas of increased spread of Covid-19.

However, when it comes to safety associated with mask-wearing specifically — not where you are wearing the mask — the answer appears to be yes.

During the European Respiratory Journal study, researchers ran a test on twelve healthy, middle-aged non-athletes to compare their performance resting and exercising. Each participant tried out three different masks: a surgical mask, a FFP2 mask (similar to a KN95 mask), or a “sham mask.” The “sham mask” was a surgical mask with a hole cut out.

The results suggested exercise capacity did decrease by 10 percent, thanks to increased “airflow resistance” from the mask. But the mask posed no danger for participants even during vigorous exercise and their ability to exercise was not greatly changed.

Piergiuseppe Agostoni is the senior author of the study and a professor of cardiology at the University of Milan. He tells Inverse this analysis “clearly” demonstrates people can successfully workout while wearing a mask, even if there is some “limitation due to the presence of the protective mask.”

The study suggests both surgical masks and KN95 masks are completely safe to exercise in.

To test the effects of wearing different masks compared to wearing no mask, the study used standard surgical masks, a FFP2 mask, and a “sham mask” hidden under a standard silicone mouthpiece standard for CPET tests or exercise tests in a lab setting.

None of the participants or their testers knew which mask they had on while conducting the trials so they wouldn’t be influenced by the kind of mask they were wearing. The mouthpiece hid the mask, and itself does not impede airflow, according to Agostini.

Sarah K. Kemble is the Hawaii Department of Health’s deputy state epidemiologist, and worked on an early case study on community spread of SARS-CoV-2 in three gyms in Hawaii. She says it’s difficult to say how likely gym workouts are to contribute to disease spread. “We don’t really know,” Kemble tells Inverse.

“What we have learned from other settings is that layered mitigation is key,” Kemble explains. “If several safety measures are taken at once, then if any one of them fails, transmission can still be reduced through the other measures that were successfully implemented.”

The CDC recommends reducing risk in the gym from multiple angles: maintaining six feet of separation, masking up, looking for well-ventilated facilities, washing hands, sanitizing surfaces, and avoiding peak hours. Notably, they also recommend taking high-intensity workouts outside.

So, if your nearby gym has great ventilation, requires mask-wearing, and enforces social distancing, for example, the risk of exposure to SARS-CoV-2 might be less compared to a gym without windows or a mask mandate.