VT/V′E inflection | Peak exercise | |||
Nonhyperinflators | Hyperinflators | Nonhyperinflators | Hyperinflators | |
Subjects n | 61 | 62 | 65 | 65 |
Work rate W | 63±21 | 66±25 | 63±21 | 66±25 |
Time min | 2.81±1.41 | 2.47±1.29 | 9.11±5.98 | 8.87±5.24 |
IC L | 2.13±0.59 | 1.99±0.59 | 2.10±0.57 | 1.87±0.57* |
ΔIC from rest L | 0.14±0.34 | -0.34±0.26* | 0.10±0.15 | -0.46±0.24* |
IC/TLC % | 30±7 | 27±7* | 30±8 | 25±7* |
VT/IC % | 72±16 | 73±12 | 72±16 | 77±12* |
EELV %TLC | 70±7 | 73±7* | 70±8 | 75±7* |
EILV %TLC | 91±5 | 92±4 | 91±6 | 94±4* |
V′E L·min−1 | 35.8±11.4 | 35.1±10.8 | 44.4±14.1 | 44.9±14.1 |
V′E/MVCpred % | 76±24 | 78±21 | 94±27 | 98±24 |
V′O2 L·min−1 | 1.10±0.36 | 1.08±0.38 | 1.25±0.40 | 1.26±0.44 |
VT L | 1.50±0.47 | 1.43±0.44 | 1.48±0.45 | 1.41±0.40 |
fR breaths·min−1 | 24.8±6.4 | 25.2±5.3 | 30.9±7.0 | 32.2±6.2 |
IRV L | 0.62±0.41 | 0.56±0.32 | 0.61±0.40 | 0.46±0.31* |
IRV %TLC | 9±5 | 8±4 | 9±6 | 6±4* |
Dyspnoea Borg | 3.5±1.5 | 3.1±1.7 | 6.8±2.1 | 6.5±2.3 |
Sp,O2% | 94±3 | 94±3 | 93±5 | 94±4 |
ΔSp,O2 from rest % | −1.6±2.4 | −1.7±2.2 | −2.4±3.5 | −2.5±3.4 |
Data are presented as mean±sd, unless otherwise stated. Inflection data are from subjects with a detectable VT inflection and peak data are from all subjects. IC: inspiratory capacity; TLC: total lung capacity; EELV: end-expiratory lung volume; EILV: end-inspiratory lung volume; MVCpred; predicted maximal ventilatory capacity based on forced expiratory volume in 1 s multiplied by 35; V′O2: oxygen uptake; fR: respiratory frequency; IRV: inspiratory reserve volume; Sp,O2: arterial oxygen saturation measured by pulse oximetry. *: p<0.05 between groups.