V′_{E} | V_{T}%VCpred | EMG_{di%max} | EMG_{di%max}/V_{T}%VCpred | |
Cycle exercise | ||||
Before | 0 (0–2.3) | 0 (0–2.6) | 0 (0–0.9) | 0 (0–1.2) |
After | 10.4 (7.0–19.8) | 9.9 (4.1–31.5) | 5.7^{#} (3.0–6.6) | 6.5 (4.7–15.2) |
p-value | 0.0005 | 0.1 | 0.0005 | 0.0005 |
Data are presented as mean (IQR) unless otherwise stated. V′_{E}: minute ventilation; V_{T}%VCpred: tidal volume expressed as a percentage of predicted vital capacity; EMG_{di%max}: mean root mean square (RMS) diaphragm electromyogram (EMG_{di}) activity per breath, expressed as a percentage of maximum RMS EMG_{di} recorded during maximal inspiratory manoeuvres. ^{#}: indicates that the slope of the normalised EMG_{di%max} and breathlessness relationship was significantly less than the slope of the normalised V′_{E} and breathlessness relationships.