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

Abstract

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) - 5.20mmHg (95% confidence interval (CI) - 6.08 to - 4.33, Po0.00001); diastolic blood pressure (DBP) MD - 3.91mmHg (95% CI - 5.68 to - 2.14, P<0.0001); and mean arterial blood pressure (MAP) MD - 3.33mmHg (95% CI - 4.01 to - 2.66, P<0.00001). Sub-analyses showed males tended to reduce MAP MD - 4.13mmHg (95% CI - 5.08 to - 3.18) more than females. Subjects aged ≥ 45 years demonstrated larger reductions in MAP MD - 5.51mmHg (95% CI - 6.95 to - 4.06) than those <45 years. Subjects undertaking ≥ 8 weeks of IRT demonstrated a larger reduction in SBP MD - 7.26mmHg (95% CI - 8.47 to - 6.04) and MAP MD - 4.22mmHg (95% CI - 5.08 to - 3.37) than those undertaking <8 weeks. Hypertensive participants in IRT demonstrated a larger reduction in MAP MD - 5.91mmHg (95% CI - 7.94 to - 3.87) than normotensive participants MD - 3.01mmHg (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.