A study from McMaster University has revealed that ketone supplements, popular among athletes to improve performance, can actually hinder performance. This study conducted in well-trained endurance athletes showed that cycling speed decreased and cardiopulmonary stress increased after taking ketone supplements, suggesting that ketone supplements serve as an alternative energy source. This contradicts the idea.
A study from McMaster University shows that ketone body supplements aimed at improving athletic performance may actually reduce performance, as evidenced by slower cycling speeds in athletes. .
Kinesiologists at McMaster University have found that ketone supplements used by some athletes hoping to cross the finish line faster can actually worsen their performance.
The new research International Journal of Sports Nutrition and Exercise Metabolismaddresses contradictory research findings regarding the effectiveness of ketone supplements, which are gaining popularity among athletes seeking a competitive advantage.
Some previously published studies have shown that supplements improve performance, while others have reported no effect or worse performance.
Left: Pre-exercise concentrations of ketone bodies in the bloodstream of participants after taking a ketone supplement or a placebo. Right: Average power output data from the participant's 20-minute cycling time trial.Credit: McMaster University
Understanding ketone bodies and their impact on your diet
Natural ketone bodies act as fuel for the brain and muscles. A ketogenic diet (characterized by very low carbohydrates and usually high fat intake) causes the body to produce more organic ketone compounds and increase their use for energy.
Devin McCarthy, a graduate student in the Department of Kinesiology at McMaster University and lead author of the study.Credit: McMaster University
Ketone supplements speed up that process without a strict diet.
“One of the main recognized benefits is that ketone bodies may act as an alternative fuel source during exercise, or potentially alter the utilization of other primary fuels such as carbohydrates and fats. In turn, it has the potential to improve endurance,” explains Martin Gibara, the book's supervising author. He is a researcher and professor in the Department of Kinesiology at McMaster University. “However, our findings suggest that this is not the case.”
Research method: Simulated race conditions
McMaster researchers recruited well-trained endurance athletes who cycled for at least five hours a week. We selected them because their athletic performance was stable from day to day. Although the experiment was conducted in the laboratory, it simulated race conditions and participants prepared as they would for a regular cycling competition.
After completing two trials that differed only in the drink provided, each participant completed a 20-minute cycling time trial that closely predicted 40 km race performance. The drinks contained either a ketone supplement or a similar-tasting placebo.
The study was structured as a double-blind study, meaning that neither the researchers nor the athletes knew whether they were provided with a ketone supplement or a placebo.
Martin Gibara is a professor in the Department of Kinesiology at McMaster University and the study's supervisor.Credit: McMaster University
Findings: Decreased speed and increased cardiopulmonary stress
“The main observation of this study was that the speed that cyclists were able to maintain during the test was reduced after taking the ketone supplement compared to a placebo,” said the study's lead author, from Tokyo says Devin McCarthy, a graduate student in the university's kinesiology department. McMaster.
The researchers say this finding is consistent with the results of their study. previous work Ketone supplements were found to increase cardiopulmonary stress during exercise.
They are currently investigating the response to different doses of the supplement at different exercise intensities to better understand how ketone bodies affect performance and potential underlying mechanisms.
Reference: “Acute Ketone Monoester Supplementation Impairs 20-min Time-Trial Performance in Trained Cyclists: A Randomized, Crossover Trial” Devin G. McCarthy, Jack Bone, Matthew Fong, Philippe JM Pinkaers, William Bostad, Douglas L. Richards, Luc Written by JC Van Loon and Martin J. Gibara, April 25, 2023. International Journal of Sports Nutrition and Exercise Metabolism.
DOI: 10.1123/ijsnem.2022-0255
