Mask use does not affect breathing or cardiovascular response during exercise

Although it can cause some discomfort, the use of tissue masks does not significantly interfere with breathing patterns and cardiovascular physiology during physical exercise at moderate to vigorous intensities. This was shown by a study with men and women not involved in competitive sport.

“The study shows that the myths that the use of a mask during physical exercise would be harmful, affecting, for example, the subject’s oxygen saturation, do not hold up. The use of protection did not significantly change the body’s functioning during the practice of moderate to heavy exercise”, says Bruno Gualano, professor at the Faculty of Medicine of the University of São Paulo (FM-USP) and author of the article.

The study, supported by FAPESP, was released on the medRxiv platform, in pre-print format, without peer review.

In the study, carried out by researchers from the USP School of Medicine, 17 healthy men and 18 women performed ergospirometric tests on a treadmill — which assess cardiopulmonary responses through the exchange of expired and inspired gases during physical exercise — at different effort intensities. Study participants ran with a three-layer fabric mask and without it, in another session, so that the comparison could be made. Different exercise intensities were evaluated.

The tests allowed us to analyze a multitude of physiological variables, such as oxygen consumption and respiratory capacity. “We also evaluated measures of cardiovascular function, oxygen saturation and acidosis in the blood. The conclusion was that the disturbances caused by the mask were very small, especially at intensities below maximum effort, which are capable of bringing enormous benefits to health”, says Gualano.

Compensatory Physiological Responses

On the other hand, at high intensities —when the subject makes as much effort as possible before getting extremely tired and stopping the exercise— it was possible to notice small respiratory changes. “But the body is able to deal with this well, through compensatory physiological responses. Oxygen saturation, heart rate, perception of exertion, lactate levels (a measure indicating the acid-base balance in the body), blood pressure , all of this is as expected, even with the use of a mask and at critical intensities”, he says.

The researcher emphasizes that the study results allow formulating new recommendations for the practice of physical exercise during the pandemic.

“Masks cannot be used as a crutch so that people do not exercise. The pandemic is long, and masks along with vaccination are necessary measures so that the virus does not spread; at the same time, it is important that people keep exercising. We saw that, between moderate and heavy intensities, which are known to be good for your health, there is no marked change in physiological factors. Therefore, it is necessary to continue using the mask indoors. physical activity are not exclusive,” he says.

“On the other hand, for those who want to exercise at exhausting intensities, they can do them outdoors, without crowding and in places where it is possible to remove the mask for a period so that there is no loss of performance. It is good to remember that, even at very high intensity , the effects of the mask were minimal”, he completes.

Another interesting point of the study was that, overall, the results were similar for both men and women. “The physiology of exercise for men and women is very different, which led us to think that there could be a different effect from the mask, but that didn’t happen,” he says.

Olympic Games with mask

The same group of researchers carried out, in partnership with the UFRN (Federal University of Rio Grande do Norte), another study with high-level athletes. “In this other study, we also observed that the masks did not affect performance. It was only the perception of effort that increased: athletes complained about the discomfort caused by the mask, but performance did not change”, he says.

Gualano reports that the study results were published before the Tokyo Olympics. “Given all the sporting, economic and organizational losses that result from the infection of a competitive athlete, we suggested at the time that it would be interesting to think about the use of a mask during training, since performance is little affected; it can be a trade- off interesting,” he says.

The researcher explains that, in general, high-performance athletes do not usually have severe Covid-19. “But the risk is not zero. In addition, there is the sport’s loss, as it has to isolate, test contacts and recover the athlete, which is a huge loss for the competitor and for the team. In the Olympic Games, we saw cases of athletes who lost the competition because they got infected. With the new wave in Europe and the United States, cases in the sport have grown substantially, and several leagues are at risk of being paralyzed”, he says.

The research team is now studying the use of masks during physical exercise with clinical groups and children. “We are testing the effects of using masks on healthy and obese children during exertion at different intensities, to understand whether masks are safe in other more vulnerable groups as well,” he says.