Acute heat stress amplifies exercise-induced metabolomic perturbations and reveals variation in circulating amino acids in endurance-trained males.

Bennett, Samuel ORCID: 0000-0002-3588-1819, Brocherie, Franck, Phelan, Marie M, Tiollier, Eve, Guibert, Elodie, Morales-Artacho, Antonio J, Lalire, Paul, Morton, James P, Louis, Julien B and Owens, Daniel J (2023) Acute heat stress amplifies exercise-induced metabolomic perturbations and reveals variation in circulating amino acids in endurance-trained males. Experimental physiology, 108 (6). pp. 838-851.

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Official URL: http://dx.doi.org/10.1113/ep090911

Abstract

<h4>New findings</h4>What is the central question of this study? Whole-body substrate utilisation is altered during exercise in hot environments, characterised by increased glycolytic metabolism: does heat stress alter the serum metabolome in response to high intensity exercise? What are the main finding and its importance? Alongside increases in glycolytic metabolite abundance, circulating amino acid concentrations are reduced following exercise under heat stress. Prior research has overlooked the impact of heat stress on protein metabolism during exercise, raising important practical implications for protein intake recommendations in the heat.<h4>Abstract</h4>Using untargeted metabolomics, we aimed to characterise the systemic impact of environmental heat stress during exercise. Twenty-three trained male triathletes ( V̇O2peak${\dot V_{{{\rm{O}}_2}{\rm{peak}}}}$ = 64.8 ± 9.2 ml kg min<sup>-1</sup> ) completed a 30-min exercise test in hot (35°C) and temperate (21°C) conditions. Venous blood samples were collected immediately pre- and post-exercise, and the serum fraction was assessed via untargeted <sup>1</sup> H-NMR metabolomics. Data were analysed via uni- and multivariate analyses to identify differences between conditions. Mean power output was higher in temperate (231 ± 36 W) versus hot (223 ± 31 W) conditions (P < 0.001). Mean heart rate (temperate, 162 ± 10 beats min<sup>-1</sup> , hot, 167 ± 9 beats min<sup>-1</sup> , P < 0.001), peak core temperature (T<sub>rec</sub> ), core temperature change (ΔT<sub>rec</sub> ) (P < 0.001) and peak rating of perceived exertion (P = 0.005) were higher in hot versus temperate conditions. Change in metabolite abundance following exercise revealed distinct clustering following multivariate analysis. Six metabolites increased (2-hydroxyvaleric acid, acetate, alanine, glucarate, glucose, lactate) in hot relative to temperate (P < 0.05) conditions. Leucine and lysine decreased in both conditions but to a greater extent in temperate conditions (P < 0.05). Citrate (P = 0.04) was greater in temperate conditions whilst creatinine decreased in hot conditions only (P > 0.05). Environmental heat stress increased glycolytic metabolite abundance and led to distinct alterations in the circulating amino acid availability, including increased alanine, glutamine, leucine and isoleucine. The data highlight the need for additional exercise nutrition and metabolism research, specifically focusing on protein requirements for exercise under heat stress.

Item Type:	Article
Uncontrolled Keywords:	Humans, Amino Acids, Alanine, Leucine, Exercise, Heat-Shock Response, Male, Hot Temperature
Divisions:	Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology
Depositing User:	Symplectic Admin
Date Deposited:	23 Apr 2024 08:20
Last Modified:	23 Apr 2024 08:20
DOI:	10.1113/ep090911
Open Access URL:	https://doi.org/10.1113/EP090911
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3180500