Peak exercise gas exchange and central haemodynamic measures
| All participants | Young (≤50 years old, n=20) | Old (≥60 years old, n=15) | p Value | |
| Peak exercise metabolic variables | ||||
| Oxygen consumption(mL/min) | 1701.4±458.9 | 1940.3±434.4 | 1382.9±255.0 | 0.00 |
| Oxygen consumption (mL/kg/min) | 25.5±8.0 | 28.6±8.8 | 21.5±4.6 | 0.00 |
| Arterial-venous oxygen difference (mLO2) | 12.5±2.9 | 12.9±3.4 | 11.9±2.2 | 0.31 |
| Respiratory exchange ratio | 1.2±0.1 | 1.2±0.1 | 1.2±0.1 | 0.55 |
| Peak exercise haemodynamics | ||||
| Heart rate (beats/min) | 156.5±19.5 | 169.2±10.4 | 139.6±15.4 | 0.00 |
| Stroke volume (mL/beat) | 89.5±19.0 | 92.5±20.0 | 85.6±17.5 | 0.29 |
| Stroke volume index (mL/beat/m2) | 51.8±9.9 | 52.5±10.9 | 50.8±8.7 | 0.63 |
| Cardiac output (L/min) | 13.9±3.2 | 15.4±3.0 | 11.9±2.3 | 0.00 |
| Cardiac index (L/min/m2) | 8.0±1.8 | 8.8±1.7 | 7.1±1.3 | 0.00 |
| Systolic blood pressure (mm Hg) | 188.9±20.3 | 182.5±21.1 | 197.6±16.0 | 0.03 |
| Diastolic blood pressure (mm Hg) | 90.9±11.3 | 90.5±12.7 | 91.4±9.4 | 0.81 |
| Mean arterial blood pressure (mm Hg) | 123.6±10.1 | 121.1±10.2 | 126.8±9.3 | 0.10 |
| Cardiac power output (W) | 3.8±0.9 | 4.1±0.8 | 3.3±0.7 | 0.01 |
| Cardiac power output index (W/m2) | 2.2±0.5 | 2.4±0.5 | 2.0±0.4 | 0.03 |
| Cardiac reserve (W) | 2.5±0.9 | 2.8±0.9 | 2.2±0.8 | 0.05 |
| Systemic vascular resistance (dyne/(s·cm5)) | 750.9±191.8 | 651.2±137.8 | 883.8±174.6 | 0.00 |