Acute response to a 2-minute isometric exercise test predicts the blood pressure-lowering efficacy of isometric resistance training in young adults

Background: This work aimed to explore whether different forms of a simple isometric exercise test could be used to predict the blood pressure (BP)-lowering efficacy of different types of isometric resistance training (IRT) in healthy young adults. In light of the emphasis on primary prevention of hypertension, identifying those with normal BP who will respond to IRT is important. Also, heightened BP reactivity increases hypertension risk, and as IRT reduces BP reactivity in patients with hypertension, it warrants further investigation in a healthy population. Methods: Forty-six young men and women (24 ± 5 years; 116 ± 10/ 68 ± 8 mmHg) were recruited from two study sites: Windsor, Canada (n=26; 13 women), and Northampton, United Kingdom (n=20; 10 women). Resting BP and BP reactivity to an isometric exercise test were assessed prior to and following 10 weeks of thrice weekly IRT. Canadian participants trained on a handgrip dynamometer (isometric handgrip, IHG), while participants in the UK trained on an isometric leg extension dynamometer (ILE). Results: Men and women enrolled in both interventions demonstrated significant reductions in systolic BP (P<0.001) and pulse pressure (PP; P<0.05). Additionally, test-induced systolic BP changes to IHG and ILE tests were associated with IHG and ILE training-induced reductions in systolic BP after 10 weeks of training, respectively (r= 0.58 and r=0.77; for IHG and ILE; P<0.05). Conclusions: The acute BP response to an isometric exercise test appears to be a viable tool to identify individuals who may respond to traditional IRT prescription.