College of Medicine, University of Central Florida, Orlando, FL, USA.
Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
Int J Sports Physiol Perform. 2024 Sep 30;19(12):1434-1443. doi: 10.1123/ijspp.2024-0143. Print 2024 Dec 1.
The first heart-rate (HR) -variability (HRV) -derived threshold based on detrended fluctuation analysis alpha 1 (DFA a1) has shown inconsistent agreement with the gas-exchange threshold (GET). This study examined whether a custom method of computing the first HRV threshold (HRVT1) based on individual HRV characteristics would improve agreement.
Fourteen participants underwent ramp incremental testing measuring gas-exchange variables and RR intervals. Comparisons were made between the oxygen consumption (V˙O2)/HR at the GET versus the V˙O2/HR at the standard DFA a1 = 0.75 (HRVT1s) or a custom value (HRVT1c) based on the DFA a1 midway between the maximum seen during the early ramp incremental and 0.5.
Mean values for GET V˙O2 versus HRVT1s V˙O2 and GETHR versus HRVT1sHR were statistically different (25.4 [3.3] vs 29.8 [6.8] mL·kg-1·min-1, P = .01, d = 0.80; 131 [11] vs 146 [22] beats·min-1, P = .005, d = 0.91). There were no statistical differences when using the HRVT1c (25.4 [3.3] vs 25.1 [5.7] mL·kg-1·min-1, P = .77, d = 0.08; 131 [11] vs 132 [17] beats·min-1, P = .65, d = 0.12). Equivalence between GET and HRVT1c V˙O2/HR was also verified. Mean maximal DFA a1 during the early ramp incremental was 1.52 (0.22) with mean HRVT1c of 1.01 (0.11). Pearson r correlation coefficients were between .67 and .70 for all GET to HRVT1 comparisons. The second HRV threshold and respiratory compensation point parameters showed agreement and correlations in line with prior studies.
The HRVT1c showed stronger agreement to GET parameters than seen using the HRVT1s. It is recommended that evaluations of the HRVT1 consider this approach in determining the HR and V˙O2 at this threshold.
基于去趋势波动分析 alpha 1（DFA a1）的首个心率（HR）-变异性（HRV）衍生阈值与气体交换阈值（GET）的一致性存在不一致。本研究旨在检验基于个体 HRV 特征计算首个 HRV 阈值（HRVT1）的定制方法是否能提高一致性。
14 名参与者进行递增斜坡测试，测量气体交换变量和 RR 间期。将 GET 时的摄氧量（V˙O2）/HR 与标准 DFA a1=0.75（HRVT1s）或基于早期斜坡递增过程中观察到的最大值和 0.5 之间的 DFA a1 中点的定制值（HRVT1c）的 V˙O2/HR 进行比较。
GET V˙O2 与 HRVT1s V˙O2 和 GETHR 与 HRVT1sHR 的平均值存在统计学差异（25.4[3.3] vs 29.8[6.8]mL·kg-1·min-1，P=0.01，d=0.80；131[11] vs 146[22]beats·min-1，P=0.005，d=0.91）。使用 HRVT1c 时没有统计学差异（25.4[3.3] vs 25.1[5.7]mL·kg-1·min-1，P=0.77，d=0.08；131[11] vs 132[17]beats·min-1，P=0.65，d=0.12）。GET 和 HRVT1c V˙O2/HR 之间的等效性也得到了验证。早期斜坡递增过程中的平均最大 DFA a1 为 1.52（0.22），平均 HRVT1c 为 1.01（0.11）。所有 GET 与 HRVT1 比较的 Pearson r 相关系数在 0.67 到 0.70 之间。第二个 HRV 阈值和呼吸补偿点参数的一致性和相关性与先前的研究一致。
HRVT1c 与 GET 参数的一致性强于 HRVT1s。建议在确定该阈值下的 HR 和 V˙O2 时，评估 HRVT1 应考虑这种方法。
