Ketogenic low-CHO, high-fat diet : The future of elite endurance sport?
Journal article
Burke, Louise. (2021). Ketogenic low-CHO, high-fat diet : The future of elite endurance sport? The Journal of Physiology. 599(3), pp. 819-843. https://doi.org/10.1113/JP278928
Authors | Burke, Louise |
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Abstract | The ability of ketogenic low-carbohydrate (CHO) high-fat (K-LCHF) diets to enhance muscle fat oxidation has led to claims that it is the ‘future of elite endurance sport’. There is robust evidence that substantial increases in fat oxidation occur, even in elite athletes, within 3–4 weeks and possibly 5–10 days of adherence to a K-LCHF diet. Retooling of the muscle can double exercise fat use to ∼1.5 g min−1, with the intensity of maximal rates of oxidation shifting from ∼45% to ∼70% of maximal aerobic capacity. Reciprocal reductions in CHO oxidation during exercise are clear, but current evidence to support the hypothesis of the normalization of muscle glycogen content with longer-term adaptation is weak. Importantly, keto-adaptation may impair the muscle's ability to use glycogen for oxidative fates, compromising the use of a more economical energy source when the oxygen supply becomes limiting and, thus, the performance of higher-intensity exercise (>80% maximal aerobic capacity). Even with moderate intensity exercise, individual responsiveness to K-LCHF is varied, with extremes at both ends of the performance spectrum. Periodisation of K-LCHF with high CHO availability might offer opportunities to restore capacity for higher-intensity exercise, but investigations of various models have failed to find a benefit over dietary approaches based on current sports nutrition guidelines. Endurance athletes who are contemplating the use of K-LCHF should undertake an audit of event characteristics and personal experiences to balance the risk of impaired performance of higher-intensity exercise with the likelihood of an unavoidable depletion of carbohydrate stores. |
Keywords | athletic performance; exercise economy; substrate utilisation |
Year | 2021 |
Journal | The Journal of Physiology |
Journal citation | 599 (3), pp. 819-843 |
Publisher | Wiley-Blackwell Publishing Ltd. |
ISSN | 0022-3751 |
Digital Object Identifier (DOI) | https://doi.org/10.1113/JP278928 |
Scopus EID | 2-s2.0-85086154834 |
Open access | Published as ‘gold’ (paid) open access |
Research or scholarly | Research |
Page range | 819-843 |
Funder | Australian Catholic University (ACU) |
Publisher's version | License File Access Level Open |
Output status | Published |
Publication dates | |
Online | 02 May 2020 |
Publication process dates | |
Accepted | 02 May 2020 |
Deposited | 12 Aug 2021 |
https://acuresearchbank.acu.edu.au/item/8w956/ketogenic-low-cho-high-fat-diet-the-future-of-elite-endurance-sport
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Publisher's version
OA_Burke_2021_Ketogenic_low_CHO_high_fat_diet.pdf | |
License: CC BY-NC-ND 4.0 | |
File access level: Open |
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