San-Millán Iñigo, Stefanoni Davide, Martinez Janel L, Hansen Kirk C, D'Alessandro Angelo, Nemkov Travis
Department of Human Physiology and Nutrition, University of Colorado Colorado Springs, Colorado Springs, CO, United States.
Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.
Front Physiol. 2020 Jun 5;11:578. doi: 10.3389/fphys.2020.00578. eCollection 2020.
The study of elite athletes provides a unique opportunity to define the upper limits of human physiology and performance. Across a variety of sports, these individuals have trained to optimize the physiological parameters of their bodies in order to compete on the world stage. To characterize endurance capacity, techniques such as heart rate monitoring, indirect calorimetry, and whole blood lactate measurement have provided insight into oxygen utilization, and substrate utilization and preference, as well as total metabolic capacity. However, while these techniques enable the measurement of individual, representative variables critical for sports performance, they lack the molecular resolution that is needed to understand which metabolic adaptations are necessary to influence these metrics. Recent advancements in mass spectrometry-based analytical approaches have enabled the measurement of hundreds to thousands of metabolites in a single analysis. Here we employed targeted and untargeted metabolomics approaches to investigate whole blood responses to exercise in elite World Tour (including Tour de France) professional cyclists before and after a graded maximal physiological test. As cyclists within this group demonstrated varying blood lactate accumulation as a function of power output, which is an indicator of performance, we compared metabolic profiles with respect to lactate production to identify adaptations associated with physiological performance. We report that numerous metabolic adaptations occur within this physically elite population ( = 21 males, 28.2 ± 4.7 years old) in association with the rate of lactate accumulation during cycling. Correlation of metabolite values with lactate accumulation has revealed metabolic adaptations that occur in conjunction with improved endurance capacity. In this population, cycling induced increases in tricarboxylic acid (TCA) cycle metabolites and Coenzyme A precursors. These responses occurred proportionally to lactate accumulation, suggesting a link between enhanced mitochondrial networks and the ability to sustain higher workloads. In association with lactate accumulation, altered levels of amino acids before and after exercise point to adaptations that confer unique substrate preference for energy production or to promote more rapid recovery. Cyclists with slower lactate accumulation also have higher levels of basal oxidative stress markers, suggesting long term physiological adaptations in these individuals that support their premier competitive status in worldwide competitions.
对精英运动员的研究为界定人类生理机能和运动表现的上限提供了独特契机。在各类运动项目中，这些运动员通过训练来优化身体的生理参数，以便在世界舞台上展开竞争。为了表征耐力水平，诸如心率监测、间接测热法以及全血乳酸测量等技术，已为探究氧气利用、底物利用与偏好以及总代谢能力提供了深入见解。然而，尽管这些技术能够测量对运动表现至关重要的个体代表性变量，但它们缺乏理解哪些代谢适应性变化对于影响这些指标是必要的所需的分子分辨率。基于质谱的分析方法的最新进展使得在单次分析中能够测量数百至数千种代谢物。在此，我们采用靶向和非靶向代谢组学方法，研究了世界巡回赛（包括环法自行车赛）职业精英自行车运动员在分级最大生理测试前后全血对运动的反应。由于该组自行车运动员表现出不同的血乳酸积累量随功率输出的变化，而功率输出是运动表现的一个指标，我们比较了与乳酸产生相关的代谢谱，以确定与生理表现相关的适应性变化。我们报告称，在这个身体机能卓越的群体（21名男性，年龄28.2±4.7岁）中，与骑行过程中乳酸积累速率相关的众多代谢适应性变化发生了。代谢物值与乳酸积累的相关性揭示了与耐力能力提高同时发生的代谢适应性变化。在这个群体中，骑行导致三羧酸（TCA）循环代谢物和辅酶A前体增加。这些反应与乳酸积累成比例发生，表明线粒体网络增强与维持更高工作负荷能力之间存在联系。与乳酸积累相关，运动前后氨基酸水平的变化表明存在适应性变化，这些变化赋予了独特的底物偏好以用于能量产生或促进更快恢复。乳酸积累较慢的自行车运动员也具有较高水平的基础氧化应激标志物，这表明这些个体存在长期的生理适应性变化，以支持他们在全球比赛中的卓越竞争地位。
