Table 2.
Response to exercise in cardiac versus pulmonary disease
| Variable | Cardiac disease | Pulmonary disease |
| Peak V̇o2 | Reduced | Reduced |
| Heart rate reserve | Usually none | Increased |
| Anaerobic threshold | Reduced (<40% predicted) | Normal or not achieved |
| Oxygen pulse | Reduced | Normal |
| V̇o2 workload ratio | Reduced | Normal |
| Peak Pao2 or O2 saturation | Normal | Decreased |
Peak V̇o2, peak oxygen uptake; Heart rate reserve, difference between predicted maximum heart rate and attained heart rate with maximum exercise; Oxygen pulse, O2 uptake divided by heart rate, represents O2 extracted by the tissues from O2 carried in each stroke volume; V̇o2 workload ratio, represents the efficiency of muscular work; Pao2, arterial oxygen tension.