Table 3—

Cycle exercise endurance time(ET) subgroups

Low-ETMid-ETHigh-ETANOVA p-value
Subjects n4334872
Male %67*7185#0.032
Age yrs64.2±6.3*61.5±7.560.6±6.70.032
Height cm169±9*171±9174±8#0.019
Weight kg70.4±13.1*,#78.1±17.079.4±15.50.010
Body mass index kg·m−224.6±4.5#26.6±5.026.3±4.80.044
COPD duration yrs8.1±6.28.8±7.09.1±7.80.756
Smoking pack-yrs58±3952±2751±260.407
FEV1 L0.95±0.39*,#1.23±0.441.35±0.41<0.0005
FEV1 % pred36±12*,#43±1344±110.001
FEV1/FVC %38±9*,#45±1146±11<0.0005
Peak work rate W50±22*,#78±3093±28#<0.0005
Peak work rate % pred37±16*,#53±1858±17#<0.0005
Peak VO2 L·min−10.83±0.23*,#1.21±0.431.39±0.41#<0.0005
Peak VO2 % pred54±21*,#71±2275±22#<0.0005
Baseline ET s150±36*,#432±1591088±203#<0.0005
IC rest L1.82±0.50*,#2.22±0.502.55±0.57#<0.0005
IC peak L1.38±0.41*,#1.80±0.582.13±0.53#<0.0005
ΔIC peak-rest L-0.45±0.30-0.41±0.38-0.41±0.430.848
Reasons for stopping exercise %0.001
 Dyspnoea59.547.731.4
 Legs13.514.220.0
 Dyspnoea+legs27.037.541.4
 Other0.00.67.1
  • Data are presented as mean±sd, unless otherwise stated. COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 s; % pred: % predicted; FVC: forced vital capacity; VO2: oxygen consumption; IC: inspiratory capacity; ΔIC peak-rest: change in IC from rest to peak exercise. *: p<0.05 low-ET versus high-ET; #: p<0.05 versus mid-ET (after Bonferroni adjustment). : analysed by Pearson Chi-squared test.