HSIN-FU LINLiao Y.-HLi P.-C.PAI-CHI LI2022-04-252022-04-25202120763417https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115614410&doi=10.3390%2fapp11188783&partnerID=40&md5=1a3d6d2430cef3a282d10b773bf31a1dhttps://scholars.lib.ntu.edu.tw/handle/123456789/607552Purpose: this study investigated the effects of the intensity of machine-based bicep curl resistance exercise on ultrafast ultrasound-derived muscle strain rate and carotid ultrafast pulse wave velocity (uf PWV), and examined the association between muscle strain rate, uf PWV, and established carotid function measures in habitual resistance-trained individuals. Methods: twenty-three young habitual resistance-trained males (age: 24 ± 1 year, body mass index = 24 ± 1 kg/m2 ) were recruited to participate in two bouts of acute bicep curl exercise. After one-repetition maximum determination (1RM), the participants were randomly assigned to engage in bicep curls at 40 or 80%1RM intensity (10 reps × five sets) by a crossover study design. The muscle strain rate of bicep muscle, carotid uf PWV during systole(uf PWV-sys), and diastole (uf PWV-dia) were obtained pre-and post-exercise. In addition, carotid function measures were calculated by obtained carotid diameter and central blood pressure changes. Results: compared with pre-exercise, the reduction in post-exercise muscle strain rate and its area under the curve of 80%1RM was greater than those of 40%1RM. Both uf PWV-sys and uf PWV-dia increased regardless of exercise intensity. Baseline bicep muscle strain rate correlated not only with uf PWV-sys (r = ?0.71, p = 0.001), uf PWV-dia (r = ?0.74, p = 0.001), but also carotid compliance (r = 0.49, p = 0.02), distensibility (r = 0.54, p = 0.01) and ? stiffness (r= ?0.84, p < 0.0001). The uf PWVs also correlated with ? stiffness (r = 0.64–0.76, p = 0.01). Conclusion: muscle stiffness measured by ultrafast ultrasound elastography increases positively with resistance exercise intensity, and it appears to correlate with carotid uf PWV and established carotid function measures in habitual resistance-trained individuals. ? 2021 by the authors. Licensee MDPI, Basel, Switzerland.Arterial stiffnessMuscle elastographyVascular function[SDGs]SDG3journal article10.3390/app111887832-s2.0-85115614410