The human oxygen uptake responses to exercise step on-transients present different shapes depending on the overshoot and/or the “slow component” manifestations. The conventional First-Order Multi-Exponential (FOME) model incorporates delayed add-on terms to comprise these phenomena, increasing parameter quantity, requiring a delayed recruitment of type II fibers to explain the “slow component,” and not offering a unified structure for different individuals and intensity domains. We hypothesized that a model composed of two Second-Order Simultaneous Components (SOSC) would present a better overall fitting performance than the FOME. Fourteen well-trained male cyclists performed repeated step on-transitions to moderate, heavy, and severe cycling intensities, whose responses were fitted with FOME and SOSC models. The SOSC presented significantly smaller (p < 0.05) root mean squared errors for moderate, supra-moderate, and all intensities combined. Along with conceptual analyses, these findings suggest the SOSC as a comprehensive alternative to the FOME model, explaining all oxygen uptake step responses with as many parameters and without delayed add-on components.

根据超调和/或“慢分量”表现，人体对运动步骤瞬态的吸氧反应呈现不同的形状。传统的一阶多指数 (FOME) 模型结合了延迟附加项来包含这些现象，增加了参数数量，需要延迟招募 II 型纤维来解释“慢分量”，并且没有提供统一的结构不同的个体和强度域。我们假设由两个二阶同时分量 (SOSC) 组成的模型将呈现比 FOME 更好的整体拟合性能。14 名训练有素的男性自行车手在过渡到中度、重度和重度骑行强度时重复进行步进，其反应符合 FOME 和 SOSC 模型。p < 0.05) 中等强度、超中等强度和所有强度组合的均方根误差。连同概念分析，这些发现表明 SOSC 是 FOME 模型的综合替代方案，解释了具有尽可能多的参数且没有延迟附加组件的所有氧气吸收阶跃响应。