Haemodynamic adaptations to isometric handgrip versus isometric wall squat exercise training: a randomised crossover study

Isometric exercise training (IET) has been shown to be an effective anti-hypertensive approach and there is a growing interest in the transition of IET into clinical exercise prescription settings. However, the most effective application of IET is not yet conclusive. As such, this work aimed to compare the haemodynamic effects of the two most prominent IET modes, the isometric wall squat (IWS) and isometric handgrip (IHG). In a cross-over design, 21 healthy participants were randomised to a 4-week IWS or IHG intervention, followed by a 4-week ‘washout’ period and then subsequent allocation to the opposite trial arm. Resting systolic (sBP) and diastolic (dBP) blood pressure, and other clinically important haemodynamic variables including heart rate (HR), stroke volume (SV), cardiac output (Q̇) and total peripheral resistance (TPR) were measured before and after the two 4-week study periods. Following the intervention, resting clinic sBP, mBP and dBP were reduced in the IWS group (-6.8 mmHg, -5.5 mmHg and -4.8 mmHg) and IHG group (-4.8 mmHg, -3.2 mmHg and -2.5 mmHg). Comparatively, there was no significant condition x time interaction for sBP (β = − 2.1 ± 1.3 mmHg, p = 0.102). Conversely, significantly greater reductions were observed for mBP (β = − 2.3 ± 0.8 mmHg, p = 0.008) and dBP (β = − 2.4 ± 1.1 mmHg, p = 0.025) following IWS compared with IHG. Overall, this study supports the utility of both isometric exercise training approaches in reducing blood pressure. While greater reductions in mBP and dBP were observed following IWS, both IWS and IHG represent effective and clinically relevant options for blood pressure management.