Adaptation to Low Carbohydrate High Fat diet is rapid but impairs endurance exercise metabolism and performance despite enhanced glycogen availability
Journal article
Burke, Louise M., Whitfield, Jamie, Heikura, Ida A., Ross, Megan L. R., Tee, Nicolin, Forbes, Sara F., Hall, Rebecca, McKay, Alannah K. A., Wallett, Alice M. and Sharma, Avish P.. (2021). Adaptation to Low Carbohydrate High Fat diet is rapid but impairs endurance exercise metabolism and performance despite enhanced glycogen availability. Journal of Physiology. 599(3), pp. 771-790. https://doi.org/10.1113/JP280221
Authors | Burke, Louise M., Whitfield, Jamie, Heikura, Ida A., Ross, Megan L. R., Tee, Nicolin, Forbes, Sara F., Hall, Rebecca, McKay, Alannah K. A., Wallett, Alice M. and Sharma, Avish P. |
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Abstract | We investigated substrate utilisation during exercise after brief (5–6 days) adaptation to a ketogenic low-carbohydrate (CHO), high-fat (LCHF) diet and similar washout period. Thirteen world-class male race walkers completed economy testing, 25 km training and a 10,000 m race (Baseline), with high CHO availability (HCHO), repeating this (Adaptation) after 5–6 days’ LCHF (n = 7; CHO: <50 g day−1, protein: 2.2 g kg−1 day−1; 80% fat) or HCHO (n = 6; CHO: 9.7 g kg−1 day−1; protein: 2.2 g kg−1 day−1) diet. An Adaptation race was undertaken after 24 h HCHO and pre-race CHO (2 g kg−1) diet, identical to the Baseline race. Substantial (>200%) increases in exercise fat oxidation occurred in the LCHF Adaptation economy and 25 km tests, reaching mean rates of ∼1.43 g min−1. However, relative urn:x-wiley:00223751:media:tjp14268:tjp14268-math-0001 (ml min−1 kg−1) was higher (P < 0.0001), by ∼8% and 5% at speeds related to 50 km and 20 km events. During Adaptation race warm-up in the LCHF group, rates of fat and CHO oxidation at these speeds were decreased and increased, respectively (P < 0.001), compared with the previous day, but were not restored to Baseline values. Performance changes differed between groups (P = 0.009), with all HCHO athletes improving in the Adaptation race (5.7 (5.6)%), while 6/7 LCHF athletes were slower (2.2 (3.4)%). Substrate utilisation returned to Baseline values after 5–6 days of HCHO diet. In summary, robust changes in exercise substrate use occurred in 5–6 days of extreme changes in CHO intake. However, adaptation to a LCHF diet plus acute restoration of endogenous CHO availability failed to restore high-intensity endurance performance, with CHO oxidation rates remaining blunted. |
Keywords | athletic performance; ketogenic diet; sports nutirition |
Year | 2021 |
Journal | Journal of Physiology |
Journal citation | 599 (3), pp. 771-790 |
Publisher | John Wiley & Sons Ltd |
ISSN | 00223751 |
Digital Object Identifier (DOI) | https://doi.org/10.1113/JP280221 |
PubMed ID | 32697366 |
Scopus EID | 2-s2.0-85089484220 |
PubMed Central ID | PMC7891450 |
Open access | Published as ‘gold’ (paid) open access |
Research or scholarly | Research |
Page range | 771-790 |
Funder | Australian Catholic University (ACU) |
Publisher's version | License File Access Level Open |
Output status | Published |
Publication dates | |
Online | 19 Aug 2020 |
Publication process dates | |
Accepted | 14 Jul 2020 |
Deposited | 25 Mar 2021 |
Grant ID | 2017000034 |
Additional information | This study was funded by a Grant from Australian Catholic University Research Fund (ACURF, 2017000034). J.W. is supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Postdoctoral Fellowship. |
https://acuresearchbank.acu.edu.au/item/8v945/adaptation-to-low-carbohydrate-high-fat-diet-is-rapid-but-impairs-endurance-exercise-metabolism-and-performance-despite-enhanced-glycogen-availability
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Publisher's version
Burke_2021_Adaptations_to_a_low_carbohydrate_high.pdf | |
License: CC BY 4.0 | |
File access level: Open |
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