Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA.
School of Kinesiology and Health Studies, Queen's University, Kingston, ON, CANADA.
Med Sci Sports Exerc. 2021 Mar 1;53(3):597-605. doi: 10.1249/MSS.0000000000002493.
Ultraendurance exercise is steadily growing in popularity; however, the effect of increasingly prolonged durations of exercise on the vascular endothelium is unknown. The aim of this study was to characterize the effect of various ultramarathon running distances on vascular form and function.
We evaluated vascular endothelial function via flow-mediated dilation (FMD) in the superficial femoral artery, as well as microvascular function, inflammatory factors, and central artery stiffness, before and after participants completed 25-km (7M:2F), 50-km (11M:10F), 80-km (9M:4F), or 160-km (9M:2F) trail races all run on the same day and course.
Completion required 149 ± 20, 386 ± 111, 704 ± 130, and 1470 ± 235 min, with corresponding average paces of 6.0 ± 0.8, 7.7 ± 2.2, 8.6 ± 1.3, and 9.6 ± 1.3 min·km-1, respectively. At baseline, there were no differences in participant characteristics across race distance groups. Shear rate stimulus trended toward an increase after the race (P = 0.07), but resting postrace artery diameter (P < 0.001) was elevated to a similar extent in all conditions. There was a reduction in FMD after the 50-km race (Δ -1.9% ± 2.2%, P < 0.01), but not the 25-km (Δ +0.3% ± 2.9%, P = 0.8), the 80-km (Δ -1.5% ± 3.2%, P = 0.1), or the 160-km (Δ +0.5% ± 2.5%, P = 0.5) race. Inflammatory markers increased most after 160 km, but arterial stiffness and microvascular function were not differently affected by race distance.
Although the superficial femoral artery baseline diameter was larger postexercise regardless of race distance, only the 50-km race reduced FMD, whereas a short-duration higher-intensity race (25 km) and longer-duration lower-intensity races (160 km) did not. Therefore, a 50-km ultramarathon may represent the intersection between higher-intensity exercise over a prolonged duration, causing reduced endothelial function not seen in shorter or longer distances.
超长耐力运动的普及度正在稳步上升；然而，运动时间的持续延长对血管内皮的影响尚不清楚。本研究旨在描述各种超长马拉松跑步距离对血管形态和功能的影响。
我们在参与者完成 25 公里（7 男：2 女）、50 公里（11 男：10 女）、80 公里（9 男：4 女）或 160 公里（9 男：2 女）越野赛后，通过股浅动脉血流介导的舒张（FMD）评估血管内皮功能，以及微血管功能、炎症因子和中心动脉僵硬度，所有比赛均在同一天和同一路线上进行。
完成比赛分别需要 149 ± 20、386 ± 111、704 ± 130 和 1470 ± 235 分钟，相应的平均速度分别为 6.0 ± 0.8、7.7 ± 2.2、8.6 ± 1.3 和 9.6 ± 1.3 min·km-1。在基线时，各组比赛的参与者特征没有差异。在比赛后，切变率刺激呈上升趋势（P = 0.07），但所有情况下休息时的血管直径（P < 0.001）都升高到相同程度。50 公里比赛后 FMD 降低（Δ -1.9% ± 2.2%，P < 0.01），但 25 公里（Δ +0.3% ± 2.9%，P = 0.8）、80 公里（Δ -1.5% ± 3.2%，P = 0.1）或 160 公里（Δ +0.5% ± 2.5%，P = 0.5）比赛没有。炎症标志物在 160 公里后增加最多，但动脉僵硬度和微血管功能不受比赛距离的影响。
尽管无论比赛距离如何，股浅动脉的基础直径在运动后都更大，但只有 50 公里比赛降低了 FMD，而短时间高强度比赛（25 公里）和长时间低强度比赛（160 公里）则没有。因此，50 公里的超长马拉松可能代表了长时间高强度运动的交点，导致内皮功能下降，而在更短或更长的距离则没有这种情况。
