Strenuous short-term dynamic exercise: effects on heart rate, blood pressure, potassium homeostasis, and packed cell volume in mild hypertension.

This study examined the effect of strenuous short-term dynamic exercise on the heart rate, blood pressure, plasma potassium and packed cell volume in mildly hypertensive subjects. At baseline a symptom-limited Bruce Exercise Protocol was carried out with blood pressure, heart rate, plasma potassium and packed cell volume measurements at fixed time points at rest and during and after the exercise. After 6 weeks of taking exercise sessions (Bruce protocol) to fatigue three times a week, the subjects were restudied. Blood pressure and the heart rate fell significantly at rest and during and after exercise. The packed cell volume was higher at all study points and plasma potassium was higher in the postexercise period after the exercise conditioning. Strenuous short-term exercise has a beneficial antihypertensive effect, raises packed cell volume and has a favourable effect on plasma potassium homeostasis.