Resistance-trained young men exhibit enhanced carotid vasoreactivity during the cold pressor test.

The function of the common carotid artery (CCA) is integral to the regulation of cerebral perfusion. Although endurance training is associated with consistent vascular benefits, the effects of resistance training on CCA function are unclear. The cold pressor test (CPT) assesses CCA vasoreactivity via sympathetic stimulation, with peak CCA vasoreactivity (CAR%peak) reflecting integrated endothelial-autonomic vascular function. In this study, we compared CAR%peak during the CPT in resistance-trained and untrained young men and examined associations with CCA stiffness and haemodynamics. CCA ultrasound was performed in 10 resistance-trained [24 years (95% confidence interval: 22,26)] and 10 untrained [24 years (22,25)] men at baseline, during a 3-min CPT and after recovery, with simultaneous haemodynamic assessment via finger plethysmography. CAR%peak was defined as the maximal percentage increase in mean diameter from baseline. Secondary outcomes included CCA stiffness indices and haemodynamics. Both groups exhibited CCA vasodilatation during CPT; however, CAR%peak was greater in resistance-trained men (P = 0.046). The resistance-trained group also displayed greater increases in systolic diameter at end-CPT (P = 0.033), alongside attenuated pulse pressure (P = 0.050; η2 p = 0.201) and β1-stiffness (P = 0.041) responses during CPT. CAR%peak was negatively correlated with baseline β2-stiffness in resistance-trained men (r = -0.655; P = 0.040), whereas in untrained control subjects it was positively correlated with peak pulse pressure (r = 0.677; P = 0.031). In conclusion, resistance-trained young men exhibit enhanced CCA vasoreactivity and attenuated pulse pressure and stiffness responses to sympathetic stimulation, reflecting favourable adaptations in endothelial-autonomic vascular regulation. These findings highlight the potential of resistance training to improve central vascular function in early adulthood.