Wearing face masks has long been recommended for the prevention of contracting or exposing others to cardiorespiratory infections. Their use in the community, outside a medical setting, has become commonplace since the start of the COVID-19 pandemic. During the current Level 4 lockdown, there has been an increased focus on mask wearing, even while outdoors and while being physically active. Many people complain bitterly about the discomfort associated with wearing a face mask at rest. As a result, it is perhaps not surprising that many people do not wish to wear a mask while exercising. The impact of wearing a mask on physical activity has recently been publicised in the media when Dr Tom Lawton, an English Intensive Care Doctor, ran 35 kilometres while simultaneously wearing a cloth mask and measuring his oxygen saturations. Media reports suggest that he wore the mask continuously (no food or drink), was comfortable and that his oxygen levels were stable at 98%. While this makes a great headline this is clearly not particularly scientific!
Fortunately, there is some more reliable data. A recent randomised controlled trial evaluated the impact of wearing either a cloth mask or surgical mask during a cycle ergometry test to exhaustion. During the study, participants had their arterial oxygen saturation (pulse oximetry), and tissue oxygenation index (muscle biopsy) assessed throughout the exercise tests. The authors showed that wearing a face mask had no effect on performance, peak power or oxygen saturation. The rate of perceived exertion (RPE), a subjective measure of how hard a participant feels they are working, and heart rate was also unchanged. As a result, the study concludes that wearing a face mask has no discernible impact on performance in young, healthy participants.
1. The results of this study are supported by a systematic review and metanalysis. Twenty-two studies involving 1,573 participants (620 females, 953 males) were included. The evidence showed that surgical and or N95 masks did not impact exercise performance, but that when the available data was pooled, wearing a mask was associated with modest increases in ratings of RPE and reported dyspnea.
2. It is important to highlight that these studies involve predominantly young and healthy participants. It is important to consider whether this data applies to all patients, especially those who have a more sedentary lifestyle and those with cardiorespiratory conditions.
Finally, it may be worth highlighting that there are some situations where people may actively choose to wear a mask while exercising. One example are people who have exercise induced bronchospasm or exercise induced asthma. These people will often wear a mask to help warm and humidify the air that they breath, especially when exercising in cold environments. This makes it less likely that they will have an exacerbation of their asthma. Another example are aerobic athletes who chose to train in an elevation mask. These masks are specifically designed to make it more difficult to breath in the hope that this might help simulate altitude training and improve performance!
In summary, for most active people, wearing a mask is safe and does not impact physiological response or performance.