Hypertensive patients have lower cardiac outputs and stroke volumes, higher heart rates, and a markedly higher peripheral resistance than normotensive individuals at the same intensity of exercise. Even patients with mildly elevated resting blood pressures have a markedly increased myocardial oxygen demand during exercise; since demand is determined not only by the pressure load but also by the degree of ventricular hypertrophy, three therapeutic inferences may be drawn: (a) Endurance training offers hypertensive patients a means of lowering exercise heart rate, reducing the systolic blood pressure and myocardial oxygen consumption, and also improving physical work capacity. (b) Besides avoiding isometric exercise, due to possible excessive peaks of blood pressure, all patients should be evaluated by ergometric testing before beginning an exercise training programme. (c) If ergometry reveals a marked rise in blood pressure at low levels of exertion, then appropriate antihypertensive medication (beta-blockers, calcium antagonists) should be prescribed prior to training.