Effect of surgical and N95 facial masks on exercise tolerance, heart rate, respiratory rate and blood oxygen saturation

Abstract

Background - Although wearing masks is inevitable these days, the effects of wearing them on physiologic parameters have not been reported. This study aimed to assess the effects of wearing no mask, a three-layer standard surgical mask, and wearing an N95 mask on blood oxygen saturation, aerobic tolerance, and performance during exercise. Methods - Twenty-one participants were enrolled in the study. Each participant was monitored with electrocardiography (ECG) while performing an exercise tolerance test using the Bruce treadmill protocol. Testing was conducted three times on different dates. Participants did not use any mask in the first test but did wear surgical and N95 masks during the second and third tests respectively. Respiratory rate (RR) was assessed for 10 seconds and then multiplied by 6. Heart rate (HR) was monitored by ECG, and oxygen saturation levels were monitored (O2Sat) via digital pulse-oximetry. Assessments were done before warm-up, at the middle and end of each Bruce stage, and as well at 1, 2, and 5 minutes into recovery (masks were worn during recovery). Results - HR, RR, and O2Sat measured data were all significantly different between the three trials at end-stage 3 of Bruce treadmill protocol (p<0.05). Although HR was still higher through the recovery period in the N95 trial in comparison with other trials (p<0.05), RR and O2Sat measured data were not different in the recovery phase. Conclusion - HR, RR, O2Sat and exercise tolerance are significantly affected by wearing surgical and N95 masks.