Imperial College London
Portrait Picture

ProfessorJulianGriffin

Faculty of Medicine, Department of Metabolism, Digestion and Reproduction

Visiting Professor
 
 
 
//

Contact

 

+44 (0)20 7594 3220julian.griffin

 
 
//

Location

 

Sir Alexander Fleming BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Dearlove:2021:10.3389/fmed.2021.721673,
author = {Dearlove, DJ and Holdsworth, D and Kirk, T and Hodson, L and Charidemou, E and Kvalheim, E and Stubbs, B and Beevers, A and Griffin, JL and Evans, R and Robertson, J and Clarke, K and Cox, PJ},
doi = {10.3389/fmed.2021.721673},
journal = {Frontiers in Medicine},
title = {β-Hydroxybutyrate Oxidation in Exercise Is Impaired by Low-Carbohydrate and High-Fat Availability},
url = {http://dx.doi.org/10.3389/fmed.2021.721673},
volume = {8},
year = {2021}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Purpose: In this study, we determined ketone oxidation rates in athletes under metabolic conditions of high and low carbohydrate (CHO) and fat availability. Methods: Six healthy male athletes completed 1 h of bicycle ergometer exercise at 75% maximal power (WMax) on three occasions. Prior to exercise, participants consumed 573 mg·kg bw−1 of a ketone ester (KE) containing a 13C label. To manipulate CHO availability, athletes undertook glycogen depleting exercise followed by isocaloric high-CHO or very-low-CHO diets. To manipulate fat availability, participants were given a continuous infusion of lipid during two visits. Using stable isotope methodology, β-hydroxybutyrate (βHB) oxidation rates were therefore investigated under the following metabolic conditions: (i) high CHO + normal fat (KE+CHO); (ii) high CHO + high fat KE+CHO+FAT); and (iii) low CHO + high fat (KE+FAT). Results: Pre-exercise intramuscular glycogen (IMGLY) was approximately halved in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both p < 0.05). Blood free fatty acids (FFA) and intramuscular long-chain acylcarnitines were significantly greater in the KE+FAT vs. other conditions and in the KE+CHO+FAT vs. KE+CHO conditions before exercise. Following ingestion of the 13C labeled KE, blood βHB levels increased to ≈4.5 mM before exercise in all conditions. βHB oxidation was modestly greater in the KE+CHO vs. KE+FAT conditions (mean diff. = 0.09 g·min−1, p = 0.03; d = 0.3), tended to be greater in the KE+CHO+FAT vs. KE+FAT conditions (mean diff. = 0.07 g·min−1; p = 0.1; d = 0.3) and were the same in the KE+CHO vs. KE+CHO+FAT conditions (p < 0.05; d < 0.1). A moderate positive correlation between pre-exercise IMGLY and βHB oxidation rates during exercise was present (p = 0.04; r = 0.5). Post-exercise intramuscular βHB abundance was markedly elevated in the KE+FAT vs. KE+CHO and KE+CHO+FAT conditions (both, p < 0.001; d
AU  - Dearlove,DJ
AU  - Holdsworth,D
AU  - Kirk,T
AU  - Hodson,L
AU  - Charidemou,E
AU  - Kvalheim,E
AU  - Stubbs,B
AU  - Beevers,A
AU  - Griffin,JL
AU  - Evans,R
AU  - Robertson,J
AU  - Clarke,K
AU  - Cox,PJ
DO  - 10.3389/fmed.2021.721673
PY  - 2021///
TI  - β-Hydroxybutyrate Oxidation in Exercise Is Impaired by Low-Carbohydrate and High-Fat Availability
T2  - Frontiers in Medicine
UR  - http://dx.doi.org/10.3389/fmed.2021.721673
VL  - 8
ER  -
Download