Isometric exercise training for blood pressure management: a systematic review and meta-analysis to optimize benefit

The objective of our study was to examine the effects of isometric resistance training (IRT) on resting blood pressure in adults. We conducted a systematic review and meta-analysis of randomized-controlled trials lasting ⩾2 weeks, investigating the effects of isometric exercise on blood pressure in healthy adults (aged ⩾18 years), published in a peer-reviewed journal between 1 January 1966 to 31 January 2015. We included 11 randomized trials, totaling 302 participants. The following reductions were observed after isometric exercise training; systolic blood pressure (SBP) mean difference (MD) -5.20 mm Hg (95% confidence interval (CI) -6.08 to -4.33, P<0.00001); diastolic blood pressure (DBP) MD -3.91 mm Hg (95% CI -5.68 to -2.14, P<0.0001); and mean arterial blood pressure (MAP) MD -3.33 mm Hg (95% CI -4.01 to -2.66, P<0.00001). Sub-analyses showed males tended to reduce MAP MD -4.13 mm Hg (95% CI -5.08 to -3.18) more than females. Subjects aged ⩾45 years demonstrated larger reductions in MAP MD -5.51 mm Hg (95% CI -6.95 to -4.06) than those <45 years. Subjects undertaking ⩾8 weeks of IRT demonstrated a larger reduction in SBP MD -7.26 mm Hg (95% CI -8.47 to -6.04) and MAP MD -4.22 mm Hg (95% CI -5.08 to -3.37) than those undertaking<8 weeks. Hypertensive participants in IRT demonstrated a larger reduction in MAP MD -5.91 mm Hg (95% CI -7.94 to -3.87) than normotensive participants MD -3.01 mm Hg (95% CI -3.73 to -2.29). Our study indicated that IRT lowers SBP, DBP and MAP. The magnitude of effect may be larger in hypertensive males aged ⩾45 years, using unilateral arm IRT for >8 weeks.