The Effect of Acute Ketone Monoester Supplementation on Glucose Oxidation During Exercise

The Effect of Acute Ketone Monoester Supplementation on Glucose Oxidation During Exercise Performed With High Rates of Carbohydrate Ingestion in Trained Cyclists

The purpose of this study is to examine the effect of exogenous ketone body supplementation on carbohydrate metabolism during exercise. In a randomized, crossover, and double-blind study, 20 endurance trained adult males and females aged 18-50 years, will ingest carbohydrates with either a ketone monoester supplement before and throughout a 3-hour exercise session or carbohydrates with a flavour-matched ketone-free placebo. The main aim of this study is to compare the exogenous carbohydrate oxidation rates during exercise between the ketone monoester and placebo conditions.

Inclusion Criteria:

• 18-50 years of age
• Trained cyclist/triathlete (VO2peak > 55 ml/kg/min for males and >48 ml/mg/min for females)
• Healthy as per medical history and investigator's/physician's judgement
• Having given written informed consent

Exclusion Criteria:

• Use of medication that could impact study outcomes and/or interfere with the expected mechanism of action of ketone supplements (e.g. Chronic use of gastric acid suppressing medication, statins, corticosteroids)
• Smoking
• Diagnosed acute or chronic medical conditions that, in the opinion of the investigator, could impact study outcomes (e.g. Diabetes mellitus)
• Diagnosed musculoskeletal disorders
• Adhering to a carbohydrate restrictive diet
• Participation in another study at the same time
• Blood donation in the 2 months before the first experimental trial
• Plasma donation in the 2 weeks before the first experimental trial
• Males: VO2peak <55 ml/min/kg body mass
• Females: VO2peak <48 ml/min/kg body mass
• Females: pregnancy