Isometric exercise training lowers resting blood pressure and improves local brachial artery flow-mediated dilation equally in men and women

Isometric resistance training has repeatedly shown to be an effective exercise modality in lowering resting blood pressure (BP), yet associated mechanisms and sex differences in the response to training remain unclear. Exploration into potential sex differences in the response to isometric resistance training is necessary, as it may allow for more optimal and sex-based exercise prescription, thereby maximizing the efficacy of the training intervention. Therefore, we investigated, in normotensives, whether sex differences exist in the response to isometric handgrip (IHG) training. Resting BP and endothelium-dependent vasodilation (brachial artery flow-mediated dilation; FMD) were assessed in 11 women (23 +/- 4 years) and 9 men (21 +/- 2 years) prior to and following 8 weeks of IHG training (four, 2-min unilateral contractions at 30 % of maximal voluntary contraction; 3 days per week). Main effects of time were observed (all P < 0.05), whereby IHG training reduced systolic BP (Delta 8 +/- 6 mmHg), diastolic BP (Delta 2 +/- 3 mmHg), mean arterial pressure (Delta 4 +/- 3 mmHg), and pulse pressure (Delta 5 +/- 7 mmHg), accompanied by increases in absolute (Delta 0.09 +/- 0.15 mm) and relative (Delta 2.4 +/- 4.1 %) brachial artery FMD; however, no significant sex differences were observed in the magnitude of post-training change in any variable assessed (all P > 0.05). IHG training effectively lowers resting BP and improves endothelium-dependent vasodilation in men and women, without significant sex differences in the magnitude of response.