Table 2

Summary of CPET data—pretrial, staged, maximal and recovery

MeasureCPET stageN*MaskedUnmaskedDifference
(95% CI)
Cohen’s d effect sizeP value
HR (bpm)3164.1±14.865.1±15.4−1 (−5.7 to 3.7)0.070.67
Systolic BP31106.5±6.9106.8±7.3−0.3 (−2.3 to 1.7)0.050.80
Diastolic BP3162.5±6.161.7±7.50.8 (−2.5 to 4.1)0.090.65
SpO23197.8±1.597.9±1.5−0.1 (−0.6 to 0.4)0.070.73
Systolic BP (mm Hg)
131122.4±13.3121.0±16.21.4 (−4 to 6.8)0.090.58
231138.6±16.3136.7±19.52 (−5.4 to 9.4)0.10.47
328†157.6±19.4150.1±22.67.5 (0.8 to 14.2)0.410.04
417†172.4±21.7163.8±22.68.6 (−0.1 to 17.3)0.470.04
55‡178.0±14.1179.6±29.1−1.6 (−32.7 to 29.5)0.05§
Diastolic BP (mm Hg)
13164.6±6.766.0±9.2−1.4 (−4.8 to 2)0.140.45
23167.9±7.167.5±8.20.4 (−2.5 to 3.3)0.050.72
328†71.2±9.169.2±10.02 (−2.5 to 6.5)0.170.32
417†74.4±10.570.1±12.14.2 (−2.6 to 11)0.290.32
5574.4±15.468.8±10.85.6 (−4.3 to 15.5)0.5
HR (bpm)
130¶100.7±18.1101.3±18−0.5 (−4.4 to 3.4)0.050.76
230¶124.9±21.4119.1±21.55.7 (−3 to 14.4)0.240.25
328¶153.0±21.5151.2±23.51.8 (−5.8 to 9.4)0.090.81
418170.4±13.1167.6±15.62.9 (−1.9 to 7.7)0.280.81
55172.0±7.6178.2±4.7−6.2 (−10.7 to 1.7)1.22
SpO2
130**96.6±1.897.3±1.3−0.6 (−1.3 to 0.1)0.30.07
229**96.4±1.896.9±1.7−0.4 (−1.1 to 0.3)0.220.15
327†**94.6±1.996.5±1.6−1.9 (−2.7 to 1.1)0.86<0.001
416¶91.9±2.194.6±2.3−2.8 (−4, to 1.6)1.17<0.001
54**92.3±3.393.5±3.1−1.3 (−3.2 to 0.6)0.68
RPE
1319.3±2.57.4±1.91.9 (1 to 2.8)0.73<0.01
23111.2±3.09.9±2.71.3 (0.4 to 2.2)0.50.01
328†14.3±2.812.9±3.01.4 (0.5 to 2.3)0.560.01
41817.0±2.115.6±2.71.4 (0.6 to 2.2)0.820.01
5518.0±3.517.6±3.60.4 (−0.4 to 1.2)0.44
Dyspnoea
1311.6±1.40.5±0.81 (0.5 to 1.5)0.71<0.001
2312.6±1.81.4±1.31.2 (0.7 to 1.7)0.92<0.001
328†4.8±2.82.8±1.82 (1.3 to 2.7)1.05<0.001
4187.2±2.64.8±2.62.4 (1.3 to 3.5)1<0.001
557.6±2.65.4±2.82.2 (−0.2 to 4.6)0.81
Bruce test duration3110:58±02:1612:38±02:17−01:39 (−02:07 to −01:11)1.25<0.001
VO2 (mL/min)302398±8813216±767−818 (−1015.5 to 620.5)1.48<0.001
VO2/kg (mL/min/kg)3032.2±9.043.9±8.1−11.6 (−14.4 to 8.8)1.51<0.001
RER301.00±0.101.09±0.08−0.09 (−0.1 to 0.1)1.13<0.001
VE/VCO22926.2±4.126.1±4.80.1 (−1.6 to 1.8)0.020.98
Dyspnoea307.2±2.95.5±2.31.7 (0.7 to 2.7)0.59<0.001
RPE3016.9±3.016.8±3.00.1 (−1.1 to 1.3)0.030.99
VE (L/min)3054.2±21.099.4±24.7−45.2 (−52.5 to 37.9)2.23<0.001
Breathing reserve (%)3063.1±10.834.6±13.828.5 (23.2 to 33.8)1.94<0.001
VO2/HR (mL/beat)3014.0±5.117.7±4.5−3.6 (−4.9 to 2.3)0.97<0.001
HR (bpm)30175.3±10.0183.7±10.8−8.4 (−14.5 to 2.3)0.490.01
Systolic BP (mm Hg)31169.0±22.7171.0±26.4−2 (−10.3 to 6.3)0.080.68
Diastolic BP (mm Hg)3176.2±10.773.9±14.52.3 (−3.6 to 8.2)0.140.27
SpO23193.4±3.195.1±2.4−1.7 (−2.8 to 0.6)0.55<0.01
Respiratory frequency3035.4±8.244.8±6.5−9.4 (−12.5 to 6.3)1.09<0.001
Tidal volume301.8±0.72.4±0.6−0.6 (−0.7 to 0.5)1.5<0.001
Completed n (%)22†† (71)29†† (93.5)22.50.02
HR (bpm)107.2±17.5111.0±18.6−3.8 (−10 to 2.4)0.260.15
Systolic BP (mm Hg)112.5±18.3110.9±21.81.6 (−9.1 to 12.3)0.060.45
Diastolic BP (mm Hg)63.1±8.860.7±8.02.5 (−1.7 to 6.7)0.260.20
SpO296.6±1.696.2±1.60.3 (−0.6 to 1.2)0.140.28
  • *Comparison included only for participants who reached the given CPET stage for both masked and unmasked trials.

  • †Missing datapoint(s) due to participant reaching exhaustion and terminating test before data could be gathered.

  • ‡Table 2 stage 5 n differs from table 1 stage 5 n due to two participants reaching exhaustion in stage 5 when unmasked and reaching exhaustion in stage 4 when masked.

  • §Insufficient n for analysis.

  • ¶Missing datapoint due to HR monitor malfunction.

  • **Missing datapoint(s) due to pulse oximeter malfunction.

  • ††N<31 due to participants removing the COSMED mask prior to completing the 7-minute recovery period.

  • BP, blood pressure; bpm, beats per minute; CPET, cardiopulmonary exercise test; HR, heart rate; RER, respiratory exchange ratio; RPE, rating of perceived exertion; VCO2, carbon dioxide production; VE, minute ventilation; VO2, oxygen consumption.