Randomized, controlled, double-blind, crossover clinical trial, depending on the product consumed, to analyze the efficacy on physical performance of a sports supplement consumed prior to and during competition or training.

Subjects who meet the selection criteria will be randomly assigned to each of the study groups (investigational product or placebo, depending on the group to which they have been assigned). On the second day, participants will consume the product that subjects did not consume on the first day.

The product to be consumed will be ketone monoester. Participants will consume 800 mg/kg body weight, distributed in two intakes. The first one, half an hour before exercise and the same dose will be consumed one hour and a half after the first dose. The intakes will be accompanied by carbohydrates and bicarbonate.

The tests that the cyclists will perform are a time trial on a cycloergometer to measure performance, as well as a 30" sprint. Afterwards, the cyclists will do a 4 and a half hour training session at competition pace. After this training session, the participants will do the same time trial and the 30'' sprint.

Inclusion Criteria:

• Male professional cyclists.
• Start the study with previous rest.

Exclusion Criteria:

• Participant suffering from chronic illness.
• Suffering a long-term injury that prevents her from training in the month prior to the intervention.
• Inability to understand the informed consent.
• Having consumed ketone bodies chronically in the previous four weeks.
• To have undergone cholecystectomy.