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.