Effects of Wearing Face Masks on Exercise Capacity and Ventilatory Anaerobic Threshold in Healthy Subjects During the COVID-19 Epidemic.

BACKGROUND Face masks have become an important part of the COVID-19 prevention approach. This study aimed to explore the effect of wearing masks on exercise ability and ventilatory anaerobic threshold (VAT). MATERIAL AND METHODS Thirty-four young, healthy volunteers were included in this study, consisting of 18 men and 16 women. The subjects were randomized to perform 2 cardiopulmonary exercise tests (CPET) on a cycle ergometer with gas exchange analysis, one with and another without wearing a face mask (cross-over design). The general data for all subjects and indicators from the 2 exercise tests performed with and without wearing a face mask were collected. RESULTS In cardiopulmonary exercise tests, wearing a mask significantly (P<0.05) decreased peak indexes (eg, work rate (WR), oxygen consumption per kg body weight (VO₂/kg), heart rate (HR), ventilation per minute (VE) and carbon dioxide ventilation equivalent (VE/VCO₂)) and anaerobic threshold indexes (eg, WR, HR, VE, breath frequency (BF), dead space ratio (VD/VT), and VE/VCO₂). However, the PETCO₂ at peak was significantly higher. There was a positive linear correlation between WR difference and VO₂ difference at VAT (abbreviated as deltaWR@VAT and deltaVO₂@VAT, respectively) (r=0.495, P=0.003). Subgroup analysis of the VAT indexes showed that WR, VO₂/kg, and VE were significantly decreased in the advanced VAT group with mask compared with the stable VAT group with mask (P<0.05). Logistic regression showed that deltaVE, deltaBF, and deltaVE/VCO₂ had independent influences on VAT. CONCLUSIONS Wearing masks advances VAT in healthy young subjects during CPET. The advanced VAT was associated with changes in VE, BF, and VE/VCO₂ while wearing masks.