Measure | CPET stage | N* | Masked | Unmasked | Difference (95% CI) | Cohen’s d effect size | P value |
HR (bpm) | 31 | 64.1±14.8 | 65.1±15.4 | −1 (−5.7 to 3.7) | 0.07 | 0.67 | |
Systolic BP | 31 | 106.5±6.9 | 106.8±7.3 | −0.3 (−2.3 to 1.7) | 0.05 | 0.80 | |
Diastolic BP | 31 | 62.5±6.1 | 61.7±7.5 | 0.8 (−2.5 to 4.1) | 0.09 | 0.65 | |
SpO2 | 31 | 97.8±1.5 | 97.9±1.5 | −0.1 (−0.6 to 0.4) | 0.07 | 0.73 | |
Systolic BP (mm Hg) | |||||||
1 | 31 | 122.4±13.3 | 121.0±16.2 | 1.4 (−4 to 6.8) | 0.09 | 0.58 | |
2 | 31 | 138.6±16.3 | 136.7±19.5 | 2 (−5.4 to 9.4) | 0.1 | 0.47 | |
3 | 28† | 157.6±19.4 | 150.1±22.6 | 7.5 (0.8 to 14.2) | 0.41 | 0.04 | |
4 | 17† | 172.4±21.7 | 163.8±22.6 | 8.6 (−0.1 to 17.3) | 0.47 | 0.04 | |
5 | 5‡ | 178.0±14.1 | 179.6±29.1 | −1.6 (−32.7 to 29.5) | 0.05 | § | |
Diastolic BP (mm Hg) | |||||||
1 | 31 | 64.6±6.7 | 66.0±9.2 | −1.4 (−4.8 to 2) | 0.14 | 0.45 | |
2 | 31 | 67.9±7.1 | 67.5±8.2 | 0.4 (−2.5 to 3.3) | 0.05 | 0.72 | |
3 | 28† | 71.2±9.1 | 69.2±10.0 | 2 (−2.5 to 6.5) | 0.17 | 0.32 | |
4 | 17† | 74.4±10.5 | 70.1±12.1 | 4.2 (−2.6 to 11) | 0.29 | 0.32 | |
5 | 5 | 74.4±15.4 | 68.8±10.8 | 5.6 (−4.3 to 15.5) | 0.5 | ||
HR (bpm) | |||||||
1 | 30¶ | 100.7±18.1 | 101.3±18 | −0.5 (−4.4 to 3.4) | 0.05 | 0.76 | |
2 | 30¶ | 124.9±21.4 | 119.1±21.5 | 5.7 (−3 to 14.4) | 0.24 | 0.25 | |
3 | 28¶ | 153.0±21.5 | 151.2±23.5 | 1.8 (−5.8 to 9.4) | 0.09 | 0.81 | |
4 | 18 | 170.4±13.1 | 167.6±15.6 | 2.9 (−1.9 to 7.7) | 0.28 | 0.81 | |
5 | 5 | 172.0±7.6 | 178.2±4.7 | −6.2 (−10.7 to 1.7) | 1.22 | ||
SpO2 | |||||||
1 | 30** | 96.6±1.8 | 97.3±1.3 | −0.6 (−1.3 to 0.1) | 0.3 | 0.07 | |
2 | 29** | 96.4±1.8 | 96.9±1.7 | −0.4 (−1.1 to 0.3) | 0.22 | 0.15 | |
3 | 27†** | 94.6±1.9 | 96.5±1.6 | −1.9 (−2.7 to 1.1) | 0.86 | <0.001 | |
4 | 16¶ | 91.9±2.1 | 94.6±2.3 | −2.8 (−4, to 1.6) | 1.17 | <0.001 | |
5 | 4** | 92.3±3.3 | 93.5±3.1 | −1.3 (−3.2 to 0.6) | 0.68 | ||
RPE | |||||||
1 | 31 | 9.3±2.5 | 7.4±1.9 | 1.9 (1 to 2.8) | 0.73 | <0.01 | |
2 | 31 | 11.2±3.0 | 9.9±2.7 | 1.3 (0.4 to 2.2) | 0.5 | 0.01 | |
3 | 28† | 14.3±2.8 | 12.9±3.0 | 1.4 (0.5 to 2.3) | 0.56 | 0.01 | |
4 | 18 | 17.0±2.1 | 15.6±2.7 | 1.4 (0.6 to 2.2) | 0.82 | 0.01 | |
5 | 5 | 18.0±3.5 | 17.6±3.6 | 0.4 (−0.4 to 1.2) | 0.44 | ||
Dyspnoea | |||||||
1 | 31 | 1.6±1.4 | 0.5±0.8 | 1 (0.5 to 1.5) | 0.71 | <0.001 | |
2 | 31 | 2.6±1.8 | 1.4±1.3 | 1.2 (0.7 to 1.7) | 0.92 | <0.001 | |
3 | 28† | 4.8±2.8 | 2.8±1.8 | 2 (1.3 to 2.7) | 1.05 | <0.001 | |
4 | 18 | 7.2±2.6 | 4.8±2.6 | 2.4 (1.3 to 3.5) | 1 | <0.001 | |
5 | 5 | 7.6±2.6 | 5.4±2.8 | 2.2 (−0.2 to 4.6) | 0.81 | ||
Bruce test duration | 31 | 10:58±02:16 | 12:38±02:17 | −01:39 (−02:07 to −01:11) | 1.25 | <0.001 | |
VO2 (mL/min) | 30 | 2398±881 | 3216±767 | −818 (−1015.5 to 620.5) | 1.48 | <0.001 | |
VO2/kg (mL/min/kg) | 30 | 32.2±9.0 | 43.9±8.1 | −11.6 (−14.4 to 8.8) | 1.51 | <0.001 | |
RER | 30 | 1.00±0.10 | 1.09±0.08 | −0.09 (−0.1 to 0.1) | 1.13 | <0.001 | |
VE/VCO2 | 29 | 26.2±4.1 | 26.1±4.8 | 0.1 (−1.6 to 1.8) | 0.02 | 0.98 | |
Dyspnoea | 30 | 7.2±2.9 | 5.5±2.3 | 1.7 (0.7 to 2.7) | 0.59 | <0.001 | |
RPE | 30 | 16.9±3.0 | 16.8±3.0 | 0.1 (−1.1 to 1.3) | 0.03 | 0.99 | |
VE (L/min) | 30 | 54.2±21.0 | 99.4±24.7 | −45.2 (−52.5 to 37.9) | 2.23 | <0.001 | |
Breathing reserve (%) | 30 | 63.1±10.8 | 34.6±13.8 | 28.5 (23.2 to 33.8) | 1.94 | <0.001 | |
VO2/HR (mL/beat) | 30 | 14.0±5.1 | 17.7±4.5 | −3.6 (−4.9 to 2.3) | 0.97 | <0.001 | |
HR (bpm) | 30 | 175.3±10.0 | 183.7±10.8 | −8.4 (−14.5 to 2.3) | 0.49 | 0.01 | |
Systolic BP (mm Hg) | 31 | 169.0±22.7 | 171.0±26.4 | −2 (−10.3 to 6.3) | 0.08 | 0.68 | |
Diastolic BP (mm Hg) | 31 | 76.2±10.7 | 73.9±14.5 | 2.3 (−3.6 to 8.2) | 0.14 | 0.27 | |
SpO2 | 31 | 93.4±3.1 | 95.1±2.4 | −1.7 (−2.8 to 0.6) | 0.55 | <0.01 | |
Respiratory frequency | 30 | 35.4±8.2 | 44.8±6.5 | −9.4 (−12.5 to 6.3) | 1.09 | <0.001 | |
Tidal volume | 30 | 1.8±0.7 | 2.4±0.6 | −0.6 (−0.7 to 0.5) | 1.5 | <0.001 | |
Completed n (%) | 22†† (71) | 29†† (93.5) | 22.5 | 0.02 | |||
HR (bpm) | 107.2±17.5 | 111.0±18.6 | −3.8 (−10 to 2.4) | 0.26 | 0.15 | ||
Systolic BP (mm Hg) | 112.5±18.3 | 110.9±21.8 | 1.6 (−9.1 to 12.3) | 0.06 | 0.45 | ||
Diastolic BP (mm Hg) | 63.1±8.8 | 60.7±8.0 | 2.5 (−1.7 to 6.7) | 0.26 | 0.20 | ||
SpO2 | 96.6±1.6 | 96.2±1.6 | 0.3 (−0.6 to 1.2) | 0.14 | 0.28 |
*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.