Cloth facemasks worn during exercise are unlikely to cause significant respiratory changes

By Suchandrima BhowmikDec 20 2021Reviewed by Aimee Molineux

Face masks have been considered as one of the most effective non-pharmacological strategies in prevention against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. The increase in vaccine coverage led several governments to ease the mask mandate. However, the resurgence of cases along with deaths in the US and Europe led to a re-issue of  the mask order which suggests that this safety tool will remain quite important until the pandemic is fully mitigated.

Several cultures had already incorporated face masks as a routine practice before the pandemic. Wearing of masks was advised even during exercise especially at gyms and fitness facilities where outbreaks of COVID-19 have been reported. However, the psychological impact of facemasks during exercise is yet to be explored.

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources

Background

Few studies have confirmed that a facemask can reduce breathing ability during exercise. Cloth face masks were found to decrease time-to-exhaustion and maximal oxygen uptake (VO2max) in untrained individuals. However, the effect of face masks on cardiorespiratory responses is mostly during exhaustive high-intensity exercise as compared to low or moderate-intensity exercise.

Constant load tests that were based on the dynamic behavior of blood acid-base status, as well as pulmonary gas exchange, were recommended to determine the effect of wearing facemasks on exercise intensities over short-stage maximal incremental tests.

Furthermore, whether men and women responded differently to wearing masks was yet to be determined. Women generally have smaller lungs and airways that reduce ventilation during exercise as compared to men. Women also have maximum cardiac output, lower oxygen (O2) carrying capacity, and arteriovenous O2 difference. Therefore, any physiological impact of mask-wearing can be more in women as compared to men.

A new study published in the pre-print server medRxiv* investigated whether wearing a cloth facemask could have physiological and perceptual responses to exercise at different exercise intensities in untrained individuals. The study also helped to determine whether a sex difference has a role in the use of masks during exercise.

About the study

The study was a crossover study that included men and women who were not engaged in any competitive sports and were therefore untrained. Individuals with pulmonary, cardiac, rheumatologic diseases, Body Mass Index (BMI) <18.5 or >30 kg/m2, or musculoskeletal limitations were excluded from the study.

A total of 35 participants (17 men and 18 women) took part in the study and were analyzed. The participants had to attend the laboratory on three separate occasions.  The first visit comprised an incremental cardiopulmonary running test to exhaustion and that helped to determine maximal oxygen uptake and ventilatory thresholds that helped to determine the running speeds for further sessions. The two remaining visits comprised of a running progressive square-wave test (PSWT) that was performed either with or without a triple-layered antiviral cloth mask. Participants were advised to refrain from caffeine, alcohol, and strenuous exercise 24 hours before each visit.

Thereafter, a pulmonary function test was carried out followed by the cardiorespiratory exercise test. The data from the cardiorespiratory exercise test was then used to determine exercise workload for the square wave treadmill test that was in accordance with the ventilatory anaerobic threshold (VAT) and the respiratory compensation point (RCP).

The progressive square-wave test (PSWT) protocol comprised three five-minute stages, moderate, heavy, and severe. After the completion of each stage, blood samples were collected from the participants for lactate analysis. Also, ventilatory and gas exchange measurements were recorded throughout the test using a breath-by-breath system.

Finally, the participants had to fill in a subjective questionnaire that was based on the impact of facemasks on nine sensations of discomfort that included, heat, itchiness, humidity, breathing resistance, feeling unfit, fatigue, saltiness, odor, and tightness.

Findings

The results indicated that wearing masks either increased, reduced, or did not alter the respiratory variables that made up  the collected respiratory data. The variables that were reduced due to wearing of masks were inspiratory capacity (IC), respiratory frequency (Rf), tidal volume (VT), ventilatory equivalent for carbon dioxide, time-to-exhaustion (TTE), forced expiratory volume in one second at rest (FEV1), forced vital capacity at rest (FVC), and peak expiratory flow at rest (PEF).

The variables that were increased due to mask-wearing were the Tobin index and end-tidal carbon dioxide pressure. The variables that were not altered due to wearing of masks were end-expiratory lung volume (EELV) and EELV/forced vital capacity (EELV/FVC), heart rate during exercise (HR), lactate, ratings of perceived exertion (RPE), blood pressure, oxygen saturation (SatO2), and FVC/FEV1 at rest.

The subjective feelings that were increased due to wearing masks were heat, misfitting, discomfort, fatigue, resistance, and humidity while saltiness, tightness, or itchiness were not affected.

Therefore, the current study indicates a reduction in exercising capacity, especially severe intensity exercise due to wearing face masks. However, no cardiovascular measure was affected by wearing a cloth face mask even at the highest exercise intensity. Furthermore, the effect of cloth facemasks on physiological measures was found to be similar in both men and women irrespective of exercise intensities. The study thus provides important insights regarding wearing cloth face masks that lead to new exercise recommendations during the COVID-19 pandemic.

Limitations

The study comprised certain limitations. First, participants had to wear a facemask over the cloth facemask for breath-by-breath measure which could further increase discomfort and cause escaping of air.

Second, the current data cannot be extrapolated to trained individuals.

Third, further investigation is required on the impact of face mask-wearing during exercise in clinical populations.

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources