The Optimal Dosage of Isometric Handgrip Exercise for Blood Pressure Reduction: Systematic Review and Meta-Analysis

The systematic review and meta-analysis aimed to examine the dose-response relationship between isometric handgrip (IHG) training and blood pressure outcomes in normotensive and hypertensive populations. Three databases (EMBASE, MEDLINE/PubMed, and Cochrane CENTRAL) were searched from inception to June 2025. Thirty-one studies with 905 participants (51% male) met the criteria. Primary outcomes were resting systolic (SBP) and diastolic blood pressure (DBP). Study quality was assessed using the PEDro scale and RoB-2. Meta-regression was used to evaluate dose-response effects on SBP and DBP. The included studies demonstrated fair to good methodological quality (5.9 ± 1.0). Moderate evidence indicated that IHG reduced SBP (-5.38 mmHg, 95% CI -6.91 to -3.85; p < 0.001; I² = 86% and DBP (-2.71 mmHg, 95% CI -3.75 to -1.66; p < 0.001; I² = 90%), with greater effects observed in hypertensive compared to normotensive groups. For meta-regression, lower training intensity protocols (<30% of maximal voluntary isometric contraction [MVIC]) yield smaller blood pressure-lowering effects in both SBP (p = 0.043) and DBP (p = 0.032). Higher weekly frequency (e.g., >3 to 7 days/week) was associated with a diminished effect in SBP (p = 0.032). In conclusion, the IHG training significantly lowers SBP and DBP in both normotensive and hypertensive individuals, offering preventive benefits for normotensive individuals at risk for hypertension and therapeutic potential for hypertensive patients. The evidence-informed protocol might appear to be four sets of 2-min unilateral contractions at ≥30 MVIC, performed ≤3 times per week for a minimum of 8 weeks. These findings support IHG as a practical non-pharmacological strategy for blood pressure management. Registration: PROSPERO number: CRD420251154235.