Gronwald Thomas, Hoos Olaf, Hottenrott Kuno
Department of Performance, Neuroscience, Therapy and Health, MSH Medical School Hamburg, University of Applied Sciences and Medical University, 20457 Hamburg, Germany.
Center for Sports and Physical Education, Julius Maximilians University of Wuerzburg, 97074 Würzburg, Germany.
J Clin Med. 2019 Feb 6;8(2):194. doi: 10.3390/jcm8020194.
Measurement of the non-linear dynamics of physiologic variability in a heart rate time series (HRV) provides new opportunities to monitor cardiac autonomic activity during exercise and recovery periods. Using the Detrended Fluctuation Analysis (DFA) technique to assess correlation properties, the present study examines the influence of exercise intensity and recovery on total variability and complexity in the non-linear dynamics of HRV. Sixteen well-trained cyclists performed interval sessions with active recovery periods. During exercise, heart rate (HR) and beat-to-beat (RR)-intervals were recorded continuously. HRV time domain measurements and fractal correlation properties were analyzed using the short-term scaling exponent alpha1 of DFA. Lactate (La) levels and the rate of perceived exertion (RPE) were also recorded at regular time intervals. HR, La, and RPE showed increased values during the interval blocks ( < 0.05). In contrast, meanRR and DFA-alpha1 showed decreased values during the interval blocks ( < 0.05). Also, DFA-alpha1 increased to the level in the warm-up periods during active recovery ( < 0.05) and remained unchanged until the end of active recovery ( = 1.000). The present data verify a decrease in the overall variability, as well as a reduction in the complexity of the RR-interval-fluctuations, owing to increased organismic demands. The acute increase in DFA-alpha1 following intensity-based training stimuli in active recovery may be interpreted as a systematic reorganization of the organism with increased correlation properties in cardiac autonomic activity in endurance trained cyclists.
测量心率时间序列（HRV）中生理变异性的非线性动力学为监测运动及恢复期间的心脏自主神经活动提供了新机会。本研究使用去趋势波动分析（DFA）技术评估相关性，探讨运动强度和恢复对HRV非线性动力学中总变异性和复杂性的影响。16名训练有素的自行车运动员进行了包含主动恢复期的间歇训练。运动期间，连续记录心率（HR）和逐搏（RR）间期。使用DFA的短期标度指数alpha1分析HRV时域测量值和分形相关性。定期记录乳酸（La）水平和主观用力程度（RPE）。在间歇训练阶段，HR、La和RPE值升高（<0.05）。相反，平均RR和DFA-alpha1在间歇训练阶段值降低（<0.05）。此外，在主动恢复期间，DFA-alpha1升高至热身阶段的水平（<0.05），并在主动恢复结束前保持不变（=1.000）。本研究数据证实，由于机体需求增加，整体变异性降低，RR间期波动的复杂性也降低。主动恢复期间基于强度的训练刺激后DFA-alpha1的急性增加，可解释为耐力训练自行车运动员心脏自主神经活动中相关性增加，机体发生系统性重组。
