Treadmill running at a high intensity yielded the greatest endothelial shear stress compared to other exercise modalities, and all exercise modalities across all intensities resulted in turbulent blood flow.
Do different exercise modalities and intensities affect endothelial shear stress and blood flow turbulence in the carotid artery of healthy young adults?
Exercises involving larger muscle groups at higher intensities, such as treadmill running, produce greater endothelial shear stress in the carotid artery, which may have implications for optimizing exercise prescriptions for atherosclerosis prevention.
p-value: p=<0.001
Endothelial dysfunction is the first pathophysiological step of atherosclerosis, which is responsible for 90% of strokes. Exercise programs aim to reduce the risk of developing stroke; however, the majority of the beneficial factors of exercise are still unknown. Endothelial shear stress (ESS) is associated with endothelial homeostasis. Unfortunately, ESS has not been characterized during different exercise modalities and intensities in the carotid artery. Therefore, the purpose of this study was to determine exercise-induced blood flow patterns in the carotid artery. Fourteen apparently healthy young adults (males = 7, females = 7) were recruited for this repeated measures study design. Participants completed maximal oxygen consumption (VO2max) tests on a Treadmill, Cycle-ergometer, and Arm-ergometer, and 1-repetition maximum (1RM) tests of the Squat, Bench Press (Bench), and Biceps Curl (Biceps) on separate days. Thereafter, participants performed each exercise at 3 different exercise intensities (low, moderate, high) while a real-time ultrasound image and blood flow of the carotid artery was obtained. Blood flow patterns were assessed by estimating ESS via Womersley’s estimation and turbulence via Reynold’s number (Re). Data were analyzed using a linear mixed-effects model. Pairwise comparisons with Holm-Bonferroni correction were conducted with Hedge’s g effect size to determine the magnitude of the difference. There was a main effect of intensity, exercise modality, and intensity * exercise modality interaction on both ESS ( p 0.001). Treadmill at a high intensity yielded the greatest ESS when compared to the other exercise modalities and intensities, while Bench Press and Biceps curls yielded the least ESS. All exercise intensities across all modalities resulted in turbulent blood flow. Clinicians must take into consideration how different exercise modalities and intensities affect ESS and Re of the carotid artery.
Montalvo et al. (Tue,) conducted a other in Healthy (n=14). Exercise modalities (treadmill, cycle, arm-ergometer, squat, bench press, biceps curl) vs. Baseline and between-modality comparisons was evaluated on Endothelial shear stress (ESS) (p=<0.001). Treadmill running at a high intensity yielded the greatest endothelial shear stress compared to other exercise modalities, and all exercise modalities across all intensities resulted in turbulent blood flow.