Department of Performance, Neuroscience, Therapy and Health, Faculty of Health Sciences, MSH Medical School Hamburg, University of Applied Sciences and Medical University, Am Kaiserkai 1, 20457 Hamburg, Germany.
Department of Internal Medicine, College of Medicine, University of Central Florida, 6850 Lake Nona Boulevard, Orlando, Florida, 32827-7408, USA.
J Sports Sci Med. 2021 Oct 1;20(4):557-563. doi: 10.52082/jssm.2021.557. eCollection 2021 Dec.
There is only very limited data examining cardiovascular responses in real-world endurance training/competition. The present study examines the influence of a marathon race on non-linear dynamics of heart rate (HR) variability (HRV). Eleven male recreational runners performed a self-paced marathon road race on an almost flat profile. During the race, heart rate and beat-to-beat (RR) intervals were recorded continuously. Besides HRV time-domain measurements, fractal correlation properties using short-term scaling exponent alpha1 of Detrended Fluctuation Analysis (DFA-alpha1) were calculated. The mean finishing time was 3:10:22 ± 0:17:56 h:min:s with a blood lactate concentration of 4.04 ± 1.12 mmol/L at the end of the race. Comparing the beginning to the end segment of the marathon race (Begin vs. End) significant increases could be found for km split time (p < .001, d = .934) and for HR (p = .010, d = .804). Significant decreases could be found for meanRR (p = .013, d = .798) and DFA-alpha1 (p = .003, d = 1.132). DFA-alpha1 showed an appropriate dynamic range throughout the race consisting of both uncorrelated and anti-correlated values. Lactate was consistent with sustained high intensity exercise when measured at the end of the event. Despite the runners slowing after halfway, DFA-alpha1 continued to fall to values seen in the highest intensity domain during incremental exercise testing in agreement with lactate assessment. Therefore, the discrepancy between the reduced running pace with that of the decline of DFA-alpha1, demonstrate the benefit of using this dimensionless HRV index as a biomarker of internal load during exercise over the course of a marathon race.
仅有非常有限的数据研究了真实耐力训练/比赛中的心血管反应。本研究考察了马拉松比赛对心率变异性（HRV）非线性动力学的影响。11 名男性业余跑步者在几乎平坦的地形上进行了自我计时的马拉松公路比赛。比赛过程中，连续记录心率和心跳（RR）间隔。除了 HRV 时域测量外，还使用去趋势波动分析（DFA-alpha1）的短期标度指数 alpha1 计算了分形关联特性。平均完赛时间为 3:10:22±0:17:56 小时：分：秒，比赛结束时血乳酸浓度为 4.04±1.12mmol/L。将马拉松比赛的开始段与结束段（Begin 与 End）进行比较，发现分段时间（p<.001，d=.934）和心率（p=.010，d=.804）显著增加。平均 RR（p=.013，d=.798）和 DFA-alpha1（p=.003，d=1.132）显著降低。DFA-alpha1 在整个比赛中表现出适当的动态范围，包括无关联和反关联值。当在比赛结束时测量时，乳酸与持续高强度运动一致。尽管跑步者在中途后速度减慢，但 DFA-alpha1 继续下降到递增运动测试中最高强度域中看到的值，与乳酸评估一致。因此，与 DFA-alpha1 下降相比，跑步速度的降低表明在马拉松比赛过程中，使用这种无维 HRV 指数作为运动中内部负荷的生物标志物具有优势。
