Format

Send to

Choose Destination
J Int Soc Sports Nutr. 2019 Apr 5;16(1):16. doi: 10.1186/s12970-019-0284-9.

Effect of a four-week ketogenic diet on exercise metabolism in CrossFit-trained athletes.

Author information

1
Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences, Wojska Polskiego 31, 60-624, Poznań, Poland. durkmich@up.poznan.pl.
2
Department of Food and Nutrition, Poznan University of Physical Education, 61-871, Poznań, Poland. durkmich@up.poznan.pl.
3
Institute of Human Nutrition and Dietetics, Poznan University of Life Sciences, Wojska Polskiego 31, 60-624, Poznań, Poland.

Abstract

BACKGROUND:

The ketogenic diet is becoming a popular nutritional model among athletes. However, the relationship between its use and metabolism during exercise seems to have not been fully investigated.

METHODS:

The aim of the study was to assess the effects of a four-week ketogenic diet (KD) on fat and carbohydrate (CHO) utilization during an incremental cycling test (ICT) in CrossFit-trained female (n = 11) and male (n = 11) athletes. During the ICT (while consuming the customary diet and after the KD), oxygen uptake and carbon dioxide exhalation were registered, and CHO and fat utilization as well as energy expenditure were calculated.

RESULTS:

In males, the KD led to an increase in fat utilization (g·min- 1·kgFFM- 1 and % oxidation). It was particularly noticeable at exercise intensities up to 80% of VO2max. An increase in the area under the curve (AUC) was seen in males but not in females at up to ≤65% VO2max of fat utilization.

CONCLUSIONS:

Male CrossFit-trained athletes seem to be more prone to shifts in macronutrient utilization (in favor of fat utilization) during submaximal intensity exercise under a ketogenic diet than are female athletes.

TRIAL REGISTRATION:

Clinical Trials Gov, NCT03665948 . Registered 11 September 2018 (retrospectively registered).

KEYWORDS:

CrossFit; Energy substrates; Exercise metabolism; Ketogenic diet; Nutritional intervention; Sport

PMID:
30953522
PMCID:
PMC6451242
DOI:
10.1186/s12970-019-0284-9
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center