The effects of an acute bout of exercise on alpha-receptor responsiveness and orthostatic tolerance in hypertensive individuals

Hypertension (high blood pressure) is a major public health issue. About 22 per cent of Canadians have hypertension, a risk factor for numerous cardiovascular diseases, including stroke, coronary heart disease, kidney failure and narrowing of the blood vessels to the arms, legs and feet. Jessica Scott is examining the effects of exercise in people with mild or moderate hypertension. Previous studies have shown an eight to 10-week physical exercise program can dramatically reduce blood pressure in hypertensive individuals. But the striking decrease in blood pressure immediately following exercise may be dangerous for these patients. While standing, gravity displaces blood away from the middle region of the body and pools in the extremities, reducing the volume of blood available to the heart. Fainting after exercise as a result of this pooling in the extremities may be the first indication of a serious cardiovascular condition. Jessica is investigating whether a sudden drop in blood pressure predisposes people with hypertension to lose consciousness following exercise. Ultimately, she aims to develop a safer, more effective exercise program for people with high blood pressure.