[Physical Activity while wearing a Mask : A Comparison of Respiratory Parameters During Submaximal Exercise between Surgical, Cloth Masks and Sham Masks ; The PAM study].

INTRODUCTION

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.