An energy drink created from ketones, rather than carbs or fat, improved performance by 2% when tested on elite cyclists, say scientists. The drink allowed the cyclists to add up to 400 metres of distance (2% increase) to their workouts.
The supplement, which will be commercially available within the year, works by temporarily switching the primary source of cellular energy from glucose or fat to ketones — molecules derived from fat that are known to be elevated in people consuming a low-carb, Atkins-like diet.
In a study of 39 cyclists, including some former Olympians, they found that the muscles use ketones when provided in the diet, and that this uptake increased in proportion to the intensity of exercise.
In one experiment, the researchers gave the cyclists ‘energy drinks,’ each containing a different source of fuel — carbohydrates, fats, or ketones — and found that cyclists who had the ketone drink had the lowest levels of lactate, a byproduct of the body’s breakdown of glucose, which is often associated with muscular stress, or the achy, tired feeling felt after a strenuous workout. The observation could help explain why the high-performing cyclists on the ketone drink travelled an average of 400 metres farther over a half hour than those consuming the carbohydrate or fat drink.
“It’s really interesting; with a single drink of nutritional ketone you can do the same exercise with completely different metabolism,” says study author Dr. Pete Cox from the University of Oxford. “Given the findings of this study, which challenges our fundamental understanding of human physiology, it will be tempting for many to focus on pursuing the endurance and sport-related avenues, but it would be a great shame if the metabolic basis of this work was not further explored.”
Ketosis is a way for humans to deal with starvation. Ketones are made in the liver from mobilised body fat, so when the body doesn’t get enough fuel from food, internal fat stores are broken down to make ketones that feed the brain. Normal metabolism is driven by the burning of carbs and fat obtained in a balanced diet.