Isometric resistance training produces clinically meaningful reductions in blood pressure
High blood pressure has been estimated to affect 1.13 billion individuals globally 1 and in a 2019 analysis , high systolic blood pressure accounted for 10.8 million deaths . 2 These figures highlight the importance of interventions to reduce both the incidence of high blood pressure and its associated mortality . While anti-hypertensive medicines are widely used and effective , another strategy that can be easily adopted by those with elevated blood pressure is exercise , and this approach appears to reduce both systolic and diastolic blood pressure . 3 One emerging method of exercise that seems to be effective is isometric resistance training ( IRT ), which is a form of strength training . In IRT , muscles produce force but do not change length , for example , holding a plank position , and there is evidence that IRT can lower blood pressure in adults . 4 The advantage of IRT is its simplicity and most previous studies have focused on squeezing a handgrip device , normally at 30 % maximal voluntary contraction , for 2 minutes , a total of four times . Although IRT can reduce blood pressure in normotensive individuals , what is less clear is whether IRT can lower blood pressure among those with elevated blood pressure .
This led a team from the Department of Exercise Physiology , School of Health Sciences , University of New South Wales , Australia , to perform a systematic review to estimate the effectiveness of IRT in those with raised blood pressure . 5 Their search was restricted to randomised controlled trials undertaken in participants with highnormal systolic blood pressure ( 130 – 139mmHg ) or diastolic ( 85 – 89mmHg ) and grade 1 ( systolic 140 – 159 , diastolic 90 – 99mmHg ) hypertension . Relevant comparators considered were aerobic exercise , dynamic resistance exercise or non-exercise controls . The primary outcome of interest was the mean difference in blood pressure scores between IRT and controls and assessments included systolic , diastolic , central or 24-hour ambulatory blood pressure .
Findings A total of 24 studies were included with 1143 participants and a mean age of 56 years ( 56 % female ). IRT was found to reduce systolic pressure by a mean of 6.97mmHg ( 95 % CI -8.77 to -5.18 , p < 0001 ) compared with controls . The mean diastolic pressure reduction was -3.86 ( 95 % CI -5.31 to -2.41 , p < 0.0001 ). Significant reductions in both systolic and diastolic pressures were also observed in those with grade 1 hypertension . When specifically compared with aerobic exercise , there was no significant difference in either systolic or diastolic pressure reductions . In addition , there were significant reductions in central systolic ( -7.48 ), diastolic ( -2.39 ) pressures but only 24-hour diastolic ( -2.39 ) pressure .
The authors noted that while significant reductions in blood pressure were observed , these were based on low quality evidence , hence there is some uncertainty over their findings . They concluded that while IRT appears to offer meaningful reductions in blood pressure , further higher-quality evidence is required .
References 1 Zhou B et al . Worldwide trends in blood pressure from 1975 to 2015 : a pooled analysis of 1479 population-based measurement studies with 19 · 1 million participants . Lancet 2017 ; 389:37 – 55 . 2 Murray CJL et al . Global burden of 87 risk factors in 204 countries and territories , 1990-2019 : a systematic analysis for the Global Burden of Disease Study 2019 . Lancet 2020 ; 396:223 – 49 . 3 Cornelissen VA et al . Exercise training for blood pressure : a systematic review and meta-analysis . J Am Heart Assoc 2013 ; 2 : e004473 . 4 Lopez-Valenciano A et al . Updated systematic review and meta-analysis on the role of isometric resistance training for resting blood pressure management in adults . J Hypertension 2019 ; 37:1320 – 33 . 5 Hansford HJ et al . The effectiveness and safety of isometric resistance training for adults with high blood pressure : a systematic review and meta-analysis . Hypertension Res 2021 . https :// doi . org / 10.1038 / s41440-021-00720-3
hospitalpharmacyeurope . com | 2021 | Issue 99 | 31