Isometric handgrip exercise induced male-specific load-dependent carotid artery stiffening (mean difference 0.50 m/s; 95% CI 0.26-0.74; p<0.001) and sex-independent structural brachial stiffening.
Does fatiguing isometric handgrip exercise alter load-dependent and structural common carotid and brachial artery stiffness in young healthy adults?
Isometric handgrip exercise induces male-specific load-dependent stiffening of carotid and brachial arteries, but maintains the normal stiffness gradient, suggesting no increased risk of pulsatile organ damage.
Effect estimate: Mean difference 0.50 m/s (95% CI 0.26 to 0.74)
p-value: p=<0.001
Acute isometric handgrip (IHG) exercise elicits a greater pressor response in males than in females, which potentially leads to sex differences in arterial stiffening via pressure-load dependent mechanisms. Regardless of blood pressure (BP), arterial structural changes also contribute to stiffening, yet their role in IHG-induced stiffening and potential sex-specific effects remains unclear. This is important given that localized stress with IHG may differentially stiffen vascular beds, with hypothetically greater effects in conduit (i.e. brachial) vs. central arteries (i.e., carotid), which would suggest preservation of the normal stiffness gradient protecting against pulsatile organ damage. PURPOSE: To determine how load-dependent and structural components contribute to common carotid and brachial artery stiffness responses following IHG in young females and males. METHODS: Twenty-nine healthy adults (18–32 years; 15 females, 14 males) performed a fatiguing IHG at 30% maximum voluntary contraction. Beat-to-beat BP was measured via finger photoplethysmography. Distensibility of the common carotid and brachial arteries was obtained from ultrasonic echo-tracking to estimate pulse wave velocity (PWV), a marker of arterial stiffness. Structural (using fixed pressures, carotid: 112/80 mmHg; brachial: 120/80 mmHg) and load-dependent PWVs were estimated from the Bramwell-Hill equation with Peterson’s modulus, using a participant-specific exponential model with a non-linear stiffness parameter. Measurements were taken before, and at 5-, 30-, and 60-min post-exercise. RESULTS: After IHG, load-dependent carotid PWV remained elevated in males (mean difference (Δ)60-pre = 0.50 m/s, 95% confidence interval (CI): 0.26 to 0.74 m/s, p< 0.001) but not in females (Δ60-pre = 0.22 m/s, 95% CI: -0.46 to 0.10 m/s, p=0.08), whereas structural carotid PWV was unchanged in both sexes (time-effect p=0.491). Conversely, structural brachial PWV remained elevated in both sexes (Δ60-pre = 1.86 m/s, 95% CI: 0.25 to 3.47 m/s, p=0.001), while only males exhibited load-dependent elevations (interaction: p=0.036). CONCLUSION: IHG induced a male-specific load-dependent stiffening of the common carotid and brachial arteries, while structure-dependent stiffening was limited to the brachial artery, independent of sex. The stiffness gradient was maintained after acute IHG, suggesting such exercise does not increase risk of pulsatile energy–mediated organ damage or adverse events, even in young males with load-dependent stiffening. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.
Scangas et al. (2026) studied Healthy (n=29). Isometric handgrip (IHG) exercise vs. Pre-exercise baseline and between sexes was evaluated on Load-dependent carotid pulse wave velocity (PWV) change from baseline to 60 minutes in males (Mean difference 0.50 m/s, 95% CI 0.26 to 0.74, p=<0.001). Isometric handgrip exercise induced male-specific load-dependent carotid artery stiffening (mean difference 0.50 m/s; 95% CI 0.26-0.74; p<0.001) and sex-independent structural brachial stiffening.