Table 1 Characteristics of the participants completing the study
From: Chronic obstructive pulmonary disease does not impair responses to resistance training
| Â | COPD | Healthy | Sex-adjusted estimated difference | |
|---|---|---|---|---|
COPD – Healthy (95% CI) | P-value | |||
General | ||||
 Participants, completing (no. ♂/♀) / dropouts†(no.) | 20 (12/8) / 2 | 58 (21/37) / 2 | – | – |
 Age (years) | 69 ± 5 (range, 60–79) | 67 ± 4 (range, 57–78) | 2 (0, 5) | 0.049* |
 Height (cm) | 171 (10) | 170 (10) | −3 (−6, 0) | 0.056 |
 Body mass (kg) | 73 (18) | 76 (16) | −7 (−14, 0) | 0.061 |
 Body mass index (kg. m2) | 25 (5) | 26 (5) | −2 (−4, 1) | 0.237 |
 Pack-years (no.) | 30 (16) | 6 (10) | 23 (17, 29) |  < 0.001* |
 GOLD grade (no. of grade II/III) | 15/5 | – | – | – |
 COPD Assessment Test™ score (0–40) | 16.6 (6.8) | – | – | – |
 Self-reported conception of health (0–10) | 4.9 (1.2) | 6.7 (1.6) | − 1.7 (− 2.5, − 0.7) | 0.001* |
Physical activity level | ||||
 Household work (kcals.week−1) | 1754 (2062) | 1866 (2201) | − 164 (− 1322, 995) | 0.779 |
 Recreational activities (kcals.week−1) | 2512 (2619) | 2654 (1841) | 188 (− 862, 1237) | 0.723 |
 Total activity (kcals.week−1) | 4266 (4036) | 4520 (2837) | 24 (− 1657, 1704) | 0.978 |
Pulmonary function | ||||
 FVC (L) | 3.2 (0.9) | 3.6 (0.9) | − 0.7 (− 1.0, − 0.4) |  < 0.001* |
 FVC (% predicted) | 97 (19) | 112 (16) | − 13 (− 22, − 4) | 0.003* |
 FEV1 (L. sec−1) | 1.5 (0.4) | 2.7 (0.7) | − 1.4 (− 1.6, − 1.2) |  < 0.001* |
 FEV1 (% predicted) | 57 (11) | 104 (16) | − 47 (− 55, − 39) |  < 0.001* |
 FEV1/FVC (%) | 47 (8) | 75 (6) | − 28 (− 31, − 24) |  < 0.001* |
 PEF (L. sec−1) | 5.0 (1.6) | 7.7 (2.1) | − 3.4 (− 4.1, − 2.7) |  < 0.001* |
Pulmonary medication | ||||
 B2-agonists (no.) | 17/20 | – | – | – |
 Muscarinic agonists (no.) | 15/20 | – | – | – |
 Medication containing both b2-agonist and glucocorticoid (no.) | 10/20 | – | – | – |
Body composition | ||||
 Total lean mass (kg) | ♂, 53 (4); ♀, 36 (6) | ♂, 60 (5); ♀, 41 (4) | − 6 (− 9, − 4) |  < 0.001* |
 Whole-body bone mineral density (g. cm2) | ♂, 1.2 (0.1); ♀, 1.0 (0.2) | ♂, 1.3 (0.1); ♀, 1.1 (0.1) | − 0.1 (− 0.2, − 0.0) | 0.007* |
 Total fat mass (kg) | ♂, 26 (10); ♀, 27 (15) | ♂, 26 (9); ♀, 25 (10) | 1 (− 5, 7) | 0.703 |
 Visceral fat (kg) | ♂, 1.9 (1.3); ♀, 1.0 (0.7) | ♂, 1.7 (1.0); ♀, 0.8 (0.7) | 0.2 (− 0.3, 0.7) | 0.412 |
Lower−-body muscle strength | ||||
 1RM leg press (kg) | ♂, 121 (35); ♀, 82 (21) | ♂, 152 (27); ♀, 124 (25) | − 36 (− 47, − 26) |  < 0.001* |
 1RM knee extension (kg) | ♂, 21 (4); ♀, 11 (4) | ♂, 31 (5); ♀, 16 (3) | − 7 (− 9, − 5) |  < 0.001* |
 Peak torque knee extension 60° . sec−1 (Nm) | ♂, 127 (34); ♀, 80 (25) | ♂, 160 32); ♀, 101 (16) | − 27 (− 36, − 17) |  < 0.001* |
 Peak torque knee extension 180° . sec−1 (Nm) | ♂, 83 (25); ♀, 47 (17) | ♂, 102 (23); ♀, 62 (11) | − 19 (− 28, − 9) |  < 0.001* |
 Peak torque knee extension 240° . sec−1 (Nm) | ♂, 68 (20); ♀, 38 (14) | ♂, 84 (20); ♀, 50 (9) | − 15 (− 20, − 9) |  < 0.001* |
 Lower-body muscle strength factor (AU) | ♂, 0.5 (0.1); ♀, 0.3 (0.1) | ♂, 0.6 (0.1); ♀, 0.4 (0.1) | − 0.1 (− 0.2, − 0.1) |  < 0.001* |
Lower-body muscle mass measures | ||||
 Leg lean mass (kg) | ♂, 18 (2); ♀, 12 (3) | ♂, 20 (2); ♀, 14 (2) | − 3 (− 4, − 2) |  < 0.001* |
 M. vastus lateralis thickness (mm) | ♂, 20 (3); ♀, 18 (5) | ♂, 22 (3); ♀, 20 (3) | − 2 (− 3, − 1) | 0.002* |
 M. rectus femoris thickness (mm) | ♂, 13 (4); ♀, 10 (3) | ♂, 16 (4); ♀, 15 (4) | − 4 (− 5, − 2) |  < 0.001* |
 Lower-body muscle mass factor (AU) | ♂, 0.6 (0.1); ♀, 0.5 (0.1) | ♂, 0.7 (0.1); ♀, 0.6 (0.1) | − 0.1 (− 0.2, − 0.1) |  < 0.001* |
Endurance measures | ||||
 Maximal power output one-legged cycling (W) | ♂, 73 (13); ♀, 48 (17) | ♂, 148 (28); ♀, 108 (21) | − 67 (− 77, − 58) |  < 0.001* |
 Maximal power output two-legged cycling (W) | ♂, 118 (38); ♀, 75 (32) | ♂, 252 (48); ♀, 167 (32) | − 113 (− 134, − 92) |  < 0.001* |
 Maximal oxygen consumption (mL O2. kg−1. min−1) | ♂, 20 (5); ♀, 16 (5) | ♂, 35 (7); ♀, 28 (6) | − 14 (− 18, − 10) |  < 0.001* |
 6 min step test (maximal number of steps) | ♂, 123 (35); ♀, 115 (44) | ♂, 208 (41); ♀, 196 (38) | − 83 (− 105, − 61) |  < 0.001* |
 1 min sit-to-stand test (maximal number) | ♂, 21 (5); ♀, 21 (6) | ♂, 30 (5); ♀, 29 (5) | − 9 (− 12, − 6) |  < 0.001* |
 nrepetitions at 50% of 1RM knee extensionpre study | ♂, 19 (5); ♀, 17 (5) | ♂, 23 (6); ♀, 20 (7) | − 4 (− 6, − 1) | 0.005* |
 One-legged endurance performance factor (AU) | ♂, 0.2 (0.0); ♀, 0.2 (0.0) | ♂, 0.4 (0.1); ♀, 0.3 (0.1) | − 0.2 (− 0.2, − 0.1) |  < 0.001* |
 Whole-body endurance performance factor (AU) | ♂, 0.4 (0.1); ♀, 0.3 (0.1) | ♂, 0.7 (0.1); ♀, 0.6 (0.1) | − 0.3 (− 0.3, − 0.2) |  < 0.001* |