Resting gas exchange and central haemodynamics measures
| All participants | Young (≤50 years old, n=20) | Old (≥60 years old, n=15) | p Value | |
| Resting metabolic variables | ||||
| Oxygen consumption (mL/min) | 244.3±35.9 | 250.2±40.9 | 236.5±27.4 | 0.20 |
| Oxygen consumption (mL/kg/min) | 3.7±0.7 | 3.7±0.9 | 3.7±0.5 | 0.81 |
| Respiratory exchange ratio | 0.9±0.1 | 0.9±0.1 | 0.9±0.1 | 0.90 |
| Resting haemodynamics | ||||
| Heart rate (beats/min) | 69.9±7.6 | 69.6±7.6 | 70.3±7.9 | 0.80 |
| Stroke volume (mL/beat) | 80.1±16.2 | 87.1±14.4 | 70.8±14.1 | 0.00 |
| Stroke volume index (mL/beat/m2) | 46.2±8.3 | 49.4±8.0 | 42.1±6.8 | 0.01 |
| Cardiac output (L/min) | 5.6±1.2 | 6.1±1.2 | 4.9±0.8 | 0.00 |
| Cardiac index (L/min/m2) | 3.2±0.6 | 3.4±0.6 | 2.9±0.4 | 0.00 |
| Systolic blood pressure (mm Hg) | 134.7±16.6 | 128.5±16.8 | 142.9±12.5 | 0.01 |
| Diastolic blood pressure (mm Hg) | 86.0±9.9 | 85.6±9.9 | 86.7±10.1 | 0.75 |
| Mean arterial blood pressure (mm Hg) | 102.2±10.7 | 99.9±10.7 | 105.4±10.2 | 0.13 |
| Cardiac power output (W) | 1.3±0.3 | 1.4±0.3 | 1.2±0.2 | 0.06 |
| Cardiac power output index (W/m2) | 0.7±0.2 | 0.8±0.2 | 0.7±0.1 | 0.13 |
| Systemic vascular resistance (dyne/(s·cm5)) | 1529.0±359.0 | 1352.1±265.6 | 1764.9±336 | 0.00 |