Cardiopulmonary physiological responses to heavy exercise in patients with anemia.

The hemodynamic adaptation of the human body to acute and chronic anemia has been extensively studied. There are few reports, however, of investigations of the response of anemic individuals to exercise. The most exhaustive study to date is that of Bishop, Donald and Wade (1), who evaluated 11 patients with anemia at moderate levels of exercise, performed in a supine position at minute ventilations up to 20 L. Preliminary observations in our laboratory indicated that subjects suffering from moderately severe anemia are capable of exerting themselves on a treadmill at levels of exercise approaching or exceeding those producing maximal oxygen intake in normal subjects. This led us to investigate the response of anemic subjects to very severe exertion.