Bilateral Intra‐individual Comparison of Vascular Structure Following Eight Weeks of Unilateral Maximal Interval Handgrip Training in Post‐Menopausal Women

There is a growing body of literature, both primary and review, that supports the use of handgrip exercise training for resting blood pressure reduction. In further investigating the causative mechanisms responsible for this blood pressure improvement researchers have identified that handgrip exercise of sustained grip contractions held for upwards of two minutes can result in working‐limb specific improvements to both vascular structure and vascular function. Training with a more dynamic handgrip exercise protocol (32 × 5sec @ maximal force with 5sec of rest between sets) was therefore expected to produce more of a local vascular stimulus and potentially result in a greater influence on vascular measures. This research presents a component of an at‐home training study where post‐menopausal women completed unilateral maximal interval handgrip exercise. Bilateral vascular assessments were completed at the onset (week0), midway (week4), and the end (week8) of training. Based on previous research, it was hypothesized that working‐limb specific changes to carotid‐radial Pulse Wave Velocity (crPWV) would be presented while measures of Augmentation Index (AIx) would remain the same. Seventeen older (61.1±4.0yrs), women without hypertension (SBP: 127.5±13.6mmHg, DBP: 77.7±8.1mmHg) completed this eight‐week unilateral (non‐dominant, left for all) training study. Women self‐reported high at‐home exercise adherence (96.9%) over the full eight weeks. Although maximal interval handgrip exercise training resulted in significant reductions to resting systolic blood pressure at both week4 (−5.7±7.7mmHg, p<0.05) and week8 (−5.1±7.7mmHg, p<0.05), vascular measures remained unchanged. Specifically, crPWV was unchanged for both the working (7.2±0.7 to 7.2±1.0) and non‐working (7.3±0.6 to 7.2±0.6) limbs. Also AIx was unchanged for both the working (32.4±6.2 to 33.1±6.6) and nonworking (33.7±5.9 to 33.0±6.9) limbs. In conclusion, post‐menopausal women completing eight weeks of maximal interval handgrip exercise training reduce their resting systolic blood pressure in the absence of alterations to local vasculature, ultimately suggesting that other mechanistic avenues may be more influential. Future research should confirm this speculation using alternative assessments of the vasculature including flow mediated dilation and ultrasound imaging of the vascular wall. Support or Funding Information Canadian Institutes of Health Research, CGS Doctoral Research Award