Ventilation index during exercise under 3 conditions
surgical mask
urethane mask
no mask
p value
Ti (sec)
1.02±0.18
0.92±0.16
0.85±0.16
0.001
RR (rate/min)
30.44±6.82
32.41±6.76
34.28±7.47
0.01
ETCO2 (%)
6.58±0.49
6.42±0.46
6.30±0.53
0.001
VE/VO2
26.21±2.90
27.53±2.75
28.22±3.29
0.05