[Physical Activity while wearing a Mask : A Comparison of Respiratory Parameters During Submaximal Exercise between...

Data on the effect of masks on ventilatory parameters are limited to maximal exercise. Their effects during submaximal exercise mimicking daily activities are unknown.

The primary endpoint was O₂ consumption (VO₂) at a level corresponding to 75% of maximum exercise capacity determined during a maximal treadmill test without a mask.

Prospective cohort study comparing the effects of surgical and cloth masks to those of a sham mask on a non-inferiority basis (threshold -2 ml/kg/min). Subjects with no apparent heart or lung disease who regularly participated in sports were included.

Seventy-five subjects were selected and 41 were analyzed (age: 37.5 ± 11.8 years, women: 34.2%, BMI: 22.5 ± 2.5 kg/m2). At 75% of maximum exercise capacity, heart rate was 164 ± 14 bpm and VO₂ was 42 ± 6 ml/min/kg with the sham mask. A slight difference in VO₂ between the sham mask and the cloth or surgical masks was observed (-2.2 and -1.4 ml/kg/min, respectively), but the lower limit of the 97.5% confidence interval (-3.0 and -2.2 ml/kg/min, respectively) exceeded the predefined non-inferiority limit of -2 ml/kg/min, and we cannot conclude non-inferiority. No differences were observed in terms of heart rate or respiratory exchange ratio (RER).

Both surgical and cloth masks slightly reduced VO₂ consumption. However, expiratory volume was reduced with both surgical and cloth masks, suggesting that the masks significantly reduced ventilation during exercise.