Aerobic versus isometric handgrip exercise in hypertension: a randomized controlled trial.

Abstract

Aerobic dynamic exercise reduces blood pressure (BP) and is broadly recommended by current American and European hypertension guidelines. Isometric exercise is currently not recommended, since data from only a few studies are available. We compare for the first time the effects of isometric handgrip training and aerobic exercise in a randomized controlled trial. A total of 75 hypertensive patients were randomized to one of the following 12-week programmes: Isometric handgrip training five times weekly (two contractions of 2 min at 30% of maximal power with each arm); 'Sham-handgrip training' five times weekly (two contractions of 2 min at 5% of maximal power with each arm); Aerobic exercise training of 30 min three to five times per week. All patients underwent office BP measurement, 24-h ambulatory BP measurement and noninvasive assessment of arterial compliance and systemic vascular resistance at baseline and after 12 weeks. Baseline epidemiological and hemodynamic characteristics did not differ between groups. Aerobic exercise led to a significant reduction of systolic 24-h BP (P = 0.025), office SBP (P = 0.03), systemic vascular resistance (P = 0.001) and small artery elasticity index (P = 0.005). There were no statistical significant changes of these parameters in the isometric exercise and the 'sham exercise' groups (P > 0.05 each). Isometric handgrip training, performed according to a typical protocol, did not reduce BP in hypertensive patients. Aerobic exercise, even as an uncontrolled and unsupervised exercise regimen, led to a significant reduction of ambulatory and office BP.