Laboratory for Myology, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
Sports Med. 2023 May;53(5):959-976. doi: 10.1007/s40279-023-01832-1. Epub 2023 Apr 3.
The observation that prior heavy or severe-intensity exercise speeds overall oxygen uptake ([Formula: see text]O) kinetics, termed the "priming effect", has garnered significant research attention and its underpinning mechanisms have been hotly debated. In the first part of this review, the evidence for and against (1) lactic acidosis, (2) increased muscle temperature, (3) O delivery, (4) altered motor unit recruitment patterns and (5) enhanced intracellular O utilisation in underpinning the priming effect is discussed. Lactic acidosis and increased muscle temperature are most likely not key determinants of the priming effect. Whilst priming increases muscle O delivery, many studies have demonstrated that an increased muscle O delivery is not a prerequisite for the priming effect. Motor unit recruitment patterns are altered by prior exercise, and these alterations are consistent with some of the observed changes in [Formula: see text]O kinetics in humans. Enhancements in intracellular O utilisation likely play a central role in mediating the priming effect, probably related to elevated mitochondrial calcium levels and parallel activation of mitochondrial enzymes at the onset of the second bout. In the latter portion of the review, the implications of priming on the parameters of the power-duration relationship are discussed. The effect of priming on subsequent endurance performance depends critically upon which phases of the [Formula: see text]O response are altered. A reduced [Formula: see text]O slow component or increased fundamental phase amplitude tend to increase the work performable above critical power (i.e. W´), whereas a reduction in the fundamental phase time constant following priming results in an increased critical power.
观察到先前的大强度或高强度运动可以加快整体氧摄取([Formula: see text]O)动力学，这被称为“启动效应”，这一现象引起了广泛的研究关注，其潜在机制也备受争议。在这篇综述的第一部分，我们讨论了乳酸酸中毒、肌肉温度升高、O 输送、运动单位募集模式改变以及细胞内 O 利用增强这五个假说在启动效应中的作用（1）、（2）、（3）、（4）和（5）。乳酸酸中毒和肌肉温度升高不太可能是启动效应的关键决定因素。虽然启动会增加肌肉的 O 输送，但许多研究表明，增加肌肉的 O 输送不是启动效应的必要条件。运动单位募集模式会因先前的运动而改变，这些改变与人类[Formula: see text]O 动力学的一些观察到的变化一致。细胞内 O 利用的增强可能在介导启动效应中起核心作用，这可能与线粒体钙水平升高以及第二阶段开始时线粒体酶的平行激活有关。在综述的后半部分，我们讨论了启动效应对功率-时间关系参数的影响。启动效应对随后的耐力表现的影响取决于[Formula: see text]O 反应的哪些阶段发生了改变。[Formula: see text]O 慢成分的减少或基本阶段幅度的增加往往会增加超过临界功率（即 W´）的可做功，而启动后基本阶段时间常数的减少会导致临界功率增加。
