Meyler Samuel, Bottoms Lindsay, Muniz-Pumares Daniel
School of Life and Medical Sciences, University of Hertfordshire, Hatfield, UK.
Exp Physiol. 2021 Jul;106(7):1410-1424. doi: 10.1113/EP089565. Epub 2021 Jun 8.
What is the topic of this review? Biological and methodological factors associated with the variable changes in cardiorespiratory fitness in response to endurance training. What advances does it highlight? Several biological and methodological factors exist that each contribute, to a given extent, to response variability. Notably, prescribing exercise intensity relative to physiological thresholds reportedly increases cardiorespiratory fitness response rates compared to when prescribed relative to maximum physiological values. As threshold-based approaches elicit more homogeneous acute physiological responses among individuals, when repeated over time, these uniform responses may manifest as more homogeneous chronic adaptations thereby reducing response variability.
Changes in cardiorespiratory fitness (CRF) in response to endurance training (ET) exhibit large variations, possibly due to a multitude of biological and methodological factors. It is acknowledged that ∼20% of individuals may not achieve meaningful increases in CRF in response to ET. Genetics, the most potent biological contributor, has been shown to explain ∼50% of response variability, whilst age, sex and baseline CRF appear to explain a smaller proportion. Methodological factors represent the characteristics of the ET itself, including the type, volume and intensity of exercise, as well as the method used to prescribe and control exercise intensity. Notably, methodological factors are modifiable and, upon manipulation, alter response rates to ET, eliciting increases in CRF regardless of an individual's biological predisposition. Particularly, prescribing exercise intensity relative to a physiological threshold (e.g., ventilatory threshold) is shown to increase CRF response rates compared to when intensity is anchored relative to a maximum physiological value (e.g., maximum heart rate). It is, however, uncertain whether the increased response rates are primarily attributable to reduced response variability, greater mean changes in CRF or both. Future research is warranted to elucidate whether more homogeneous chronic adaptations manifest over time among individuals, as a result of exposure to more homogeneous exercise stimuli elicited by threshold-based practices.
本综述的主题是什么？与耐力训练后心肺适能的可变变化相关的生物学和方法学因素。它突出了哪些进展？存在几个生物学和方法学因素，每个因素在一定程度上都对反应变异性有影响。值得注意的是，据报道，相对于生理阈值规定运动强度，与相对于最大生理值规定运动强度相比，可提高心肺适能反应率。由于基于阈值的方法在个体间引发更均匀的急性生理反应，随着时间的推移重复进行时，这些一致的反应可能表现为更均匀的慢性适应，从而降低反应变异性。
耐力训练（ET）后心肺适能（CRF）的变化存在很大差异，这可能是由于多种生物学和方法学因素所致。据认为，约20%的个体对ET可能无法实现有意义的CRF增加。遗传学是最主要的生物学因素，已被证明可解释约50%的反应变异性，而年龄、性别和基线CRF似乎解释的比例较小。方法学因素代表ET本身的特征，包括运动类型、运动量和强度，以及规定和控制运动强度的方法。值得注意的是，方法学因素是可改变的，通过操纵这些因素可改变对ET的反应率，无论个体的生物学易感性如何，均可引起CRF增加。特别是，相对于生理阈值（如通气阈值）规定运动强度，与相对于最大生理值（如最大心率）规定强度相比，可提高CRF反应率。然而，增加的反应率是否主要归因于反应变异性降低、CRF的更大平均变化或两者兼而有之尚不确定。有必要进行未来研究，以阐明由于接触基于阈值的实践所引发的更均匀的运动刺激，个体间是否会随着时间的推移表现出更均匀的慢性适应。
