A single progressive upright treadmill or upright bicycle exercise test may be used to safely evaluate the functional aerobic capacity of patients with chronic cardiac failure of varying severity and origin. The non-invasive monitoring or respiratory gas exchange and the determination of VO2 max and the anaerobic threshold may be used to objectively grade the severity of chronic cardiac failure and the heart's pumping reserve. The serial monitoring of these indices of exercise performance should prove useful in following the natural history of cardiac disease and in assessing the response to various therapeutic interventions.