Ketone supplements may reduce athletic performance

Ketone supplements, intended to boost athletic performance, may reduce it, as evidenced by slower cycling speeds in athletes, a study suggests. The research, published in the International Journal of Sport Nutrition and Exercise Metabolism, analyzed contradictory findings related to the effectiveness of ketone supplements, which have gained popularity among athletes seeking a competitive advantage. Some previously published studies had shown the supplements improve performance, while others have reported they had no effect or even worsened performance, the researchers said. Natural ketones can serve as fuels for the brain and muscles. A ketogenic diet – characterized by very low carbohydrate and typically high fat intake – causes the body to produce more organic ketone compounds and increase their use for energy, they said. “One of the main perceived benefits is that ketones may serve as an alternative fuel source during exercise or potentially alter the utilization of other major fuels such as carbohydrates and fats, and in turn enhance endurance capacity,” said Martin Gibala, a professor at McMaster University in the UK. “But our findings suggest that is not the case,” Gibala said. The researchers recruited well-trained endurance athletes who cycled five or more hours per week, selecting them because their athletic performance is consistent from day to day.