Keto supplements popular among athletes to improve performance may actually hinder performance improvements, a McMaster University study suggests. This study of highly trained endurance athletes showed reduced cycling speed and increased cardiorespiratory stress after taking ketone supplements, contradicting the belief that ketone supplements serve as an alternative energy source.

Research from McMaster University suggests that ketone supplements designed to improve athletic performance may actually decrease performance, as evidenced by slower cycling speeds in athletes.

Kinesiology experts at McMaster University have found that ketone supplements used by some athletes looking to cross the finish line faster may actually decrease athletic performance. The new study, published in the International Journal of Sports Nutrition and Exercise Metabolism, resolves conflicting findings related to the effectiveness of ketone supplements, which are growing in popularity among athletes looking for a competitive edge.

Some previously published studies have shown that ketone supplementation can improve performance, while other studies have reported that ketone supplementation has no effect or even causes performance to decrease.

Left: Ketone body concentrations in the blood of participants before exercise after ingesting ketone supplements or placebo. The image on the right shows average power output data for participants in a 20-minute cycling time trial. Source: McMaster University

Learn about ketones and their impact on diet

Natural ketones act as fuel for your brain and muscles. The ketogenic diet - which is characterized by very low carbohydrate intake and often high fat intake - causes the body to produce more organic ketone compounds and increase its use of energy. Keto supplements can speed up this process without requiring a strict diet.

Devin McCarthy is a graduate student in the Department of Athletics at McMaster University and the first author of the study. Source: McMaster University

Martin Gibala, a professor in the Department of Kinesiology at McMaster University and lead author of the study, explained: "One of the main benefits is that ketone bodies can serve as an alternative fuel source during exercise, or potentially enhance endurance capacity by changing the utilization of other primary fuels such as carbohydrates and fats. But our results show that this is not the case."

Research methods: simulated competition conditions

Researchers at McMaster University recruited highly trained endurance athletes who cycled for five or more hours per week, chosen because their performance was consistent from day to day. The experiment was conducted in a laboratory but simulated race conditions, with participants preparing as they would for a normal bike race.

Each competitor completed two trials, with different drinks, before completing a 20-minute cycling time trial. The drinks contained either ketone supplements or a placebo that tasted similar.

The study was double-blind, meaning neither the researchers nor the athletes knew whether they were being given a ketone supplement or a placebo.

Martin Gibala, professor in the Department of Athletics at McMaster University, is the lead author of the study. Source: McMaster University

Study results: Speed ​​decreased, cardiorespiratory stress increased

"The main observation of this study is that cyclists were able to maintain lower speeds during the test after drinking ketone supplements compared to placebo," said study lead author Devin McCarthy, a graduate student in McMaster University's Department of Kinesiology.

The researchers say these findings are consistent with their previous research, which found that ketone supplements increase cardiorespiratory stress during exercise.

They are currently studying the response to different doses of supplementation at different exercise intensities to better understand how ketones affect exercise performance and the underlying mechanisms.

Compiled source: ScitechDaily