Table 2 The CPET parameters of within-group comparisons between mask-on condition and mask-off condition in male group and female group, respectively

 VO₂/kg (unload)

ml/min/kg

7.60 ± 1.40

9.27 ± 1.71

< 0.001

6.75 ± 0.76

9.13 ± 1.55

< 0.001

 VO₂/kg (peak)

ml/min/kg

28.65 ± 3.53

33.22 ± 4.31

0.001

22.54 ± 3.87

26.61 ± 4.03

< 0.001

 VO₂/kg (AT)

ml/min/kg

18.93 ± 2.98

21.24 ± 3.60

0.001

15.45 ± 2.18

19.39 ± 3.07

< 0.001

 VO_2AT/VO_2max

%

40.13 ± 5.55

45.13 ± 6.96

0.002

41.25 ± 5.37

51.69 ± 6.55

< 0.001

 O₂/HR (unload)

ml/kg/beat

5.23 ± 0.69

6.19 ± 0.99

0.001

3.52 ± 0.55

4.83 ± 0.96

< 0.001

 O₂/HR (peak)

ml/kg/beat

10.92 ± 2.04

12.33 ± 1.83

0.001

6.77 ± 1.16

7.89 ± 0.88

< 0.001

 △VO₂/△WR

ml/(min*watt)

7.97 ± 0.93

8.91 ± 0.68

0.004

7.74 ± 1.37

8.70 ± 0.80

0.022

 MET (unload)

–

2.17 ± 0.39

2.65 ± 0.49

< 0.001

1.93 ± 0.22

2.59 ± 0.44

< 0.001

 MET (peak)

–

8.23 ± 1.00

9.52 ± 1.26

0.001

6.47 ± 1.13

7.61 ± 1.14

< 0.001

 HR (unload)

bpm

94.07 ± 11.40

97.27 ± 11.18

0.324

97.50 ± 7.87

96.44 ± 9.33

0.620

 HR (peak)

bpm

172.20 ± 9.17

176.13 ± 9.38

0.248

168.44 ± 14.60

169.94 ± 12.70

0.392

 HRR

bpm

21.60 ± 9.52

20.67 ± 9.05

0.769

27.81 ± 13.44

26.69 ± 13.34

0.477

 SpO₂ (unload)

%

99.14 ± 0.95

99.00 ± 1.30

0.635

99.33 ± 1.18

98.80 ± 1.15

0.178

 SpO₂ (peak)

%

96.18 ± 2.56

98.36 ± 1.36

0.043

95.00 ± 2.26

96.42 ± 2.50

0.236

 VT (unload)

l

0.75 ± 0.17

0.8 ± 0.15

0.221

0.49 ± 0.09

0.62 ± 0.11

0.001

 VT (peak)

l

1.94 ± 0.29

2.16 ± 0.37

0.001

1.22 ± 0.22

1.36 ± 0.21

0.003

 RER (unload)

%

0.81 ± 0.09

0.82 ± 0.04

0.736

0.80 ± 0.07

0.78 ± 0.10

0.350

 RER (peak)

%

1.22 ± 0.10

1.25 ± 0.09

0.408

1.18 ± 0.08

1.22 ± 0.08

0.161

 BR% (unload)

%

90.20 ± 1.47

87.73 ± 1.94

< 0.001

89.88 ± 2.31

86.00 ± 2.78

< 0.001

 BR% (peak)

%

52.07 ± 11.76

45.93 ± 10.44

0.032

60.19 ± 9.83

50.44 ± 8.16

< 0.001

 V_E/VCO₂ (slope)

ratio

27.32 ± 3.66

24.92 ± 2.17

0.031

27.38 ± 5.35

27.24 ± 3.12

0.883

 V_E (unload)

l

14.17 ± 1.91

17.95 ± 2.00

< 0.001

10.42 ± 2.36

14.63 ± 2.58

< 0.001

 V_E (peak)

l

71.59 ± 16.83

82.02 ± 17.01

0.015

42.46 ± 10.09

53.95 ± 10.33

< 0.001

 Load_max

watt

190.33 ± 33.54

193.8 ± 37.06

0.488

106.06 ± 19.25

109.26 ± 18.23

0.084

 Exercise duration

sec

499.20 ± 76.16

502.40 ± 85.48

0.745

505.13 ± 79.74

515.69 ± 78.45

0.138

 Borg’s scale

scores

13.07 ± 1.94

12.53 ± 1.64

0.424

13.06 ± 1.18

12.37 ± 0.96

0.081

 Exercise duration

min

499.20 ± 76.16

502.40 ± 84.48

0.745

505.16 ± 79.74

515.69 ± 78.45

0.138