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Original Research ARTICLE

Front. Physiol. | doi: 10.3389/fphys.2020.00578

Metabolomics of Endurance Capacity in World Tour Professional Cyclists Provisionally accepted The final, formatted version of the article will be published soon. Notify me

 Iñigo San-Millán1, 2*, Davide Stefanoni3, Janel L. Martinez1, Kirk C. Hansen3,  Angelo D. Alessandro3 and  Travis Nemkov3*
  • 1Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, United States
  • 2Department of Human Physiology and Nutrition, University of Colorado Colorado Springs, United States
  • 3Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, United States

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 (n=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 TCA cycle metabolites and CoA 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.

Keywords: Metabolomics, elite athletes, Endurance, Exercise, Lactate, Oxidative Stress, amino acid metabolism, mitochondrial metabolism

Received: 28 Feb 2020; Accepted: 08 May 2020.

Copyright: © 2020 San-Millán, Stefanoni, Martinez, Hansen, Alessandro and Nemkov. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Dr. Iñigo San-Millán, University of Colorado Anschutz Medical Campus, Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, Aurora, 80045, Colorado, United States, inigo.sanmillan@cuanschutz.edu
Dr. Travis Nemkov, University of Colorado Anschutz Medical Campus, Biochemistry and Molecular Genetics, Aurora, 80045, Colorado, United States, travis.nemkov@ucdenver.edu