The evidence of effectiveness of isometric resistance training on the management of hypertension in adults: an umbrella review

Hypertension is the leading risk factor for cardiovascular disease yet also one of the most readily preventable causes of death. Isometric resistance training (IRT) has gained increasing popularity in recent times as a viable nonpharmacological management option for hypertension. Whilst there have been several reviews on this topic, with varying findings, this umbrella review aimed to summarize the current evidence underpinning the effectiveness of IRT for hypertension. Quantitative systematic reviews and meta-analyses published in English were considered for inclusion. Commercially produced and grey literature was searched between December 2021 and January 2022. Methodological quality of included reviews was determined using the AMSTAR 2 critical appraisal tool. Customized data extraction tools were developed for this review and data were synthesized using the National Health and Medical Research Council FORM Framework. Twelve reviews published between 2011 and 2021 of varying methodological quality were identified. Isometric handgrip exercise training with four sets of 2-min contractions and 1 min rest period between each set was the most utilized intervention, undertaken three times per week for at least 8 weeks. Collectively, there is consistent evidence to indicate IRT has positive impacts on SBP and DBP as well as mean arterial pressure. These positive impacts were reported for normotensive as well as hypertensive individuals. Given IRT is a readily available, easy-to-use intervention with minimal financial cost, it could be considered a viable treatment option for people with, and at risk of, hypertension.