Rothschild Jeffrey A, Gallo Gabriele, Hamilton Kate, Stevenson Julian D, Dudley-Rode Harrison, Charoensap Thanchanok, Plews Daniel J, Kilding Andrew E, Maunder Ed
Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand.
High Performance Sport New Zealand, Auckland, New Zealand.
Eur J Appl Physiol. 2025 May 22. doi: 10.1007/s00421-025-05815-0.
To assess relationships between heart rate (HR), ventilation (̇ ), and respiratory frequency (F) decoupling and durability of the first ventilatory threshold (VT), and the strength of practical models to predict power output at VT during prolonged exercise.
Durability of VT was assessed via measurements of power output at VT before and after ~ 2.5-h of initially moderate-intensity cycling in 51 trained cyclists, as part of four studies published elsewhere. In 12 of those participants, power output at VT was assessed every hour until task failure. For every assessment of power output at VT, HR, F, and ̇ was measured at fixed power outputs, and thus decoupling of these variables with power output was determined. Bivariate repeated-measures correlations (r) between decoupling and durability of VT were assessed. Multivariable models were created to predict power output at VT during prolonged exercise using generalised estimating equations.
Negative correlations were observed between exercise-induced change in power output at VT and HR (r = -0.76, P < 0.001) and F (r = -0.40, P = 0.013) decoupling, but not ̇ decoupling (r = -0.25, P = 0.136). The final prediction model, containing baseline VT and peak oxygen uptake, F decoupling, and an interaction between HR decoupling and exercise duration, effectively predicted real-time VT (mean absolute error, ~ 7.2 W; R, 0.95).
HR and/or F decoupling during controlled training sessions may be a practically useful durability assessment. Our prediction models may be an effective means of improving within-session intensity regulation and training load monitoring.
评估心率（HR）、通气量（̇ ）和呼吸频率（F）解耦与第一通气阈值（VT）的耐久性之间的关系，以及预测长时间运动中VT时功率输出的实用模型的强度。
在51名训练有素的自行车运动员中，通过测量最初约2.5小时中等强度骑行前后VT时的功率输出，评估VT的耐久性，这是在其他地方发表的四项研究的一部分。在其中12名参与者中，每小时评估一次VT时的功率输出，直至任务失败。对于VT时功率输出的每次评估，在固定功率输出下测量HR、F和̇ ，从而确定这些变量与功率输出的解耦。评估解耦与VT耐久性之间的双变量重复测量相关性（r）。使用广义估计方程创建多变量模型，以预测长时间运动中VT时的功率输出。
观察到运动引起的VT时功率输出变化与HR解耦（r = -0.76，P < 0.001）和F解耦（r = -0.40，P = 0.013）呈负相关，但与̇ 解耦无关（r = -0.25，P = 0.136）。最终的预测模型包含基线VT、峰值摄氧量、F解耦以及HR解耦与运动持续时间之间的相互作用，有效地预测了实时VT（平均绝对误差，约7.2 W；R，0.95）。
在有控制的训练期间，HR和/或F解耦可能是一种实用的耐久性评估方法。我们的预测模型可能是改善训练期间强度调节和训练负荷监测的有效手段。
