Table 3. Results from the maximal cycle ergometry test.
| Healthy controls | COPD | COPDND | COPDD | |
| Total exercise time, min | 10.0 (8.8, 10.6) | 7.4 (5.5, 9.4)** | 7.5 (5.5, 8.9)* | 7.0 (5.7, 9.7)* |
| Peak work load, Watt | 156 (134, 255) | 72 (56, 96)*** | 76 (66, 100)*** | 66 (53, 96)*** |
| Work load, % predicted | 133 (106, 152) | 60 (44, 71)*** | 65 (48, 73)*** | 57 (37, 69)*** |
| V′o 2peak, ml/min | 1852 (1680, 2785) | 1130 (1025, 1406)*** | 1162 (1075, 1434)*** | 1084 (901, 1358)*** |
| V′o 2peak, % predicted | 120 (102, 155) | 74 (55, 84)*** | 78 (66, 88)*** | 64 (51, 74)*** |
| V′e ,peak, % MVV | 66 (61, 80) | 85 (81, 94)*** | 82 (77, 94)** | 89 (82, 94)** |
| HRpeak, % HR predicted | 100 (97, 106) | 78 (68, 89)*** | 77 (66, 89)** | 78 (71, 92)** |
| ATV′o 2, ml/min | 1061 (862, 1395) | 736 (607, 873)*** | 776 (601, 875)** | 727 (605, 889)** |
| S p,o 2 at V′o 2peak, % | 97 (97, 99) | 92 (87, 95)*** | 94 (93, 96)*** | 87 (85, 90)***, ### |
| ΔS p,o 2, % | −1.0 (−2.0, 0.0) | −4.0 (−8.0, −2.3)*** | −3.0 (−4.0, 0.0) | −8.0 (−10.0, −6.5)***, ### |
| ΔS a,o 2, % | 0.0 (0.0, 1.0) | −1.0 (−4.0, 0.0)* | −1.0 (−1.8, 1.5) | −4.0 (−10.0, −3.0)**, ## |
Values are expressed as median (25th percentile, 75th percentile). Abbreviations: V′o 2, oxygen uptake; V′e, minute ventilation; MVV, maximal voluntary ventilation, calculated as FEV1×37.5; HR, heart rate; HR predicted calculated as (220 − age); ATV′o 2, V′o 2 at anaerobic threshold; S p,o 2, oxygen saturation measured via pulse oximetry; S a,o 2, arterial oxygen saturation. Level of significance of difference vs. controls: *p<0.05, **p<0.01, ***p≤0.001. Level of significance of difference COPDD vs. COPDND patients: ##p<0.01, ###p≤0.001.