Van Hooren Bas, Mennen Bram, Gronwald Thomas, Bongers Bart C, Rogers Bruce
Department of Nutrition and Movement Sciences, School of Nutrition and Translational Research in Metabolism (NUTRIM), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands.
MSH Medical School Hamburg, Institute of Interdisciplinary Exercise Science and Sports Medicine, Hamburg, Germany.
J Sports Sci. 2025 Jan;43(2):125-134. doi: 10.1080/02640414.2023.2277034. Epub 2023 Nov 2.
The short-term scaling exponent alpha1 of detrended fluctuation analysis (DFA-a1) of heart rate variability (HRV) has shown potential to delineate the first ventilatory threshold (VT1). The aims of this study were to investigate the accuracy of this method for VT1 determination in runners using a consumer grade chest belt and to explore the effects of acute fatigue.
We compared oxygen uptake (O) and heart rate (HR) at gas exchange VT1 to O and HR at a DFA-a1 value of 0.75. Gas exchange and HRV data were obtained from 14 individuals during a treadmill run involving two incremental ramps. Agreement was assessed using Bland-Altman analysis and linear regression.
Bland-Altman analysis between gas exchange and HRV O and HR at VT1 during the first ramp showed a mean (95% limits of agreement) bias of -0.5 (-6.8 to 5.8) ml∙kg∙min, and -0.9 (-12.2 to 10.5) beats∙min, with R of 0.83 and 0.56, respectively. During the second ramp, the differences were -7.3 (-18.1 to 3.5) ml∙kg∙min and -12.3 (-30.4 to 5.9) beats∙min, with R of 0.62 and 0.43, respectively.
A chest-belt derived DFA-a1 of 0.75 is closely related to gas exchange VT1, with the variability in accuracy at an individual level being similar to gas exchange methods. This suggests this to be a useful method for exercise intensity demarcation. The altered relationship during the second ramp indicates that DFA-a1 is only able to accurately demarcate exercise intensity thresholds in a non-fatigued state, but also opens opportunities for fatigue-based training prescription.
心率变异性（HRV）的去趋势波动分析（DFA-a1）的短期标度指数α1已显示出描绘第一通气阈值（VT1）的潜力。本研究的目的是使用消费级胸带调查该方法在跑步者中确定VT1的准确性，并探讨急性疲劳的影响。
我们将气体交换VT1时的摄氧量（O）和心率（HR）与DFA-a1值为0.75时的O和HR进行了比较。气体交换和HRV数据是在14名个体进行涉及两个递增斜坡的跑步机跑步期间获得的。使用Bland-Altman分析和线性回归评估一致性。
在第一个斜坡期间，气体交换与HRV的O和VT1时的HR之间的Bland-Altman分析显示平均（95%一致性界限）偏差为-0.5（-6.8至5.8）ml∙kg∙min和-0.9（-12.2至10.5）次∙min，R分别为0.83和0.56。在第二个斜坡期间，差异分别为-7.3（-18.1至3.5）ml∙kg∙min和-12.3（-30.4至5.9）次∙min，R分别为0.62和0.43。
胸带得出的DFA-a1值为0.75与气体交换VT1密切相关，个体水平上准确性的变异性与气体交换方法相似。这表明这是一种用于运动强度划分的有用方法。第二个斜坡期间关系的改变表明DFA-a1不仅能够在非疲劳状态下准确划分运动强度阈值，而且还为基于疲劳的训练处方提供了机会。
