Acute effects of volume‐matched isometric exercise intensity on vascular function and autonomic regulation in men with elevated blood pressure

Abstract Isometric exercise (IE) has been introduced as an effective non‐pharmacological strategy for blood pressure (BP) management; however, the influence of exercise intensity remains unclear during lower‐limb IE. This study investigated the acute effects of volume‐matched high‐intensity (HIIE) and low‐intensity IE (LIIE) on cardiovascular function in men with elevated BP. Seventeen men with prehypertension or stage I hypertension completed three randomized crossover conditions, including HIIE (60% of maximal voluntary contraction (MVC)), LIIE (30% of MVC), and a non‐exercise control condition (CON). BP, heart rate variability (HRV), brachial‐ankle pulse wave velocity (baPWV) were measured at baseline and three different time points during recovery, while flow‐mediated dilation (FMD) was measured at baseline and 30‐min post‐exercise. No significant BP reduction was observed. However, HIIE induced greater autonomic disturbance with elevated heart rate and reduced HRV indices during recovery ( p  p  p  < 0.001). Our findings suggest that volume‐matched HIIE induces greater acute autonomic and vascular responses than LIIE in men with elevated BP, despite no immediate changes in BP. HIIE may provide a stronger physiological stimulus associated with vascular adaptation.