Sex‐differences in the effects of isometric handgrip training on resting blood pressure and resistance vessel function

Abstract

Isometric handgrip (IHG) training lowers resting blood pressure (BP) in normotensive and hypertensive populations, yet potential sex‐differences and mechanisms associated with the hypotensive response remain unclear. We studied, in normotensives, sex‐differences in the effects of IHG training on resting BP and resistance vessel function (RVF), a hypothesized mechanism of post‐training BP reduction. Resting BP (brachial artery oscillometry) and RVF (venous strain gauge plethysmography with reactive hyperaemia) were assessed in 12 females (23 ± 4 yrs; mean ± SD) and 9 males (21 ± 2 yrs), pre‐ and post‐ 8 wks of IHG training (Four, 2 min unilateral contractions at 30% of maximal effort, 3 d•wk−1). IHG training reduced resting systolic BP in both females and males (Females: 94 ± 6 to 88 ± 5 mmHg; Males: 105 ± 10 to 96 ± 7 mmHg, all P < 0.05), but the magnitude of BP reduction was similar between sexes (P >; 0.05). Diastolic BP remained unchanged in both females and males (Females: 57 ± 7 to 54 ± 6 mmHg; Males: 57 ± 5 to 56 ± 5 mmHg, all P >; 0.05). In each sex, systolic BP reductions occurred concomitant to increases in forearm reactive hyperaemic blood flow (Females: 26 ± 7 to 36 ± 9 mL•min−1•100 mL−1; Males: 35 ± 11 to 38 ± 13 mL•min−1•100 mL−1, all P < 0.05). In conclusion, IHG training effectively lowers resting BP in both females and males, and improved RVF may mediate the post‐training BP response in both sexes. Supported by University of Windsor.