A total of 146 patients with chronic ischaemic heart disease and 90 normal persons were subjected to step-wise bicycle ergometry tests with an analysis of ECG, pulse rate, spiroergometry, cardiac volumes, and ultrasonic location of the posterior wall of the left ventricle. It was demonstrated that the pulse-pressure index that results in ischaemic manifestations can be determined in every patient, i.e. this index reflects the limit of oxygen consumption by the myocardium. Considerable limitations of the cardiac reserve result in early initiation of extracardiac mechanisms of homeostasis preservation--arterial pressure elevation, increasing dynamic viscosity of the blood, relatively moderate pulse rate increase. The noneconomic nature of such a response to the additional load predisposes the development of ischaemic disorders, acidosis and reduction of total oxygen consumption. The obtained data illustrate the importance of the test for the selection of optimum levels of training exercises.