Isometric handgrip exercise training attenuates blood pressure in prehypertensive subjects at 30% maximum voluntary contraction.

Abstract

Prehypertension highlights a category of subjects who are at high risk of developing hypertension. This study assessed the blood pressure attenuating effect of isometric handgrip exercise in the management of prehypertension. A total of 400 prehypertensive subject with a mean age of 40 ± 10 years and recently diagnosed as prehypertension were recruited for the study. They were randomly distributed into exercise and control groups (n = 200). The control group was placed on lifestyle modification only, while the exercise group performed a 24 consecutive days isometric hand grip exercise training at 30% maximum voluntary contraction (MVC) for 2 min each day in combination with lifestyle modification protocol. The results show a statistically significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP). The exercise group had a mean reduction of 7.48 ± 0.06 and 6.41 ± 1.01 mmHg of the SBP and DBP, respectively. It was further observed that both the SBP and DBP and pulse rate significantly increased acutely within 5 min post exercise at 30% MVC with a mean value of 8.60 ± 0.20 mmHg, 7.33 ± 0.03 mmHg, and 8.24 ± 0.20 beats/min of the SBP and DBP and pulse rate, respectively. However, this increase returned to pre-exercise value within 10 min post exercises to a mean value of -0.68 + 1.64 mmHg, 1.48 ± 1.02 mmHg, and 3.00 ± 0.11 beats/min, respectively. This study has shown that isometric handgrip exercise is effective in the attenuation of blood pressure in prehypertensive subjects especially when combined with the routinely recommended lifestyle modifications. However, caution should be taken when recommending it because of acute increase in blood pressure.