Oral Ketones and Exercise Among Patients With Long-chain Fatty Acid Oxidation Disorders

Purpose: Subjects with long-chain fatty acid oxidation disorders (LC-FAOD) do not make ketones during fasting or with exercise. Ketones are an important alternative energy substrate during moderate exercise, sparing the oxidation of glucose and providing a source of ATP to the central nervous system and exercising muscle. Fatty acid oxidation in the liver is required to make ketones. Subjects with a LC-FAOD cannot generate ketones because of their block in fatty acid oxidation during exercise. Providing ketones in an oral ketone beverage may increase blood ketones with exercise to levels normally observed in humans. Aim: To determine the safety and tolerability of an oral ketone beverage during moderate intensity exercise among subjects with a LC-FAOD compared to an isocaloric maltodextrin beverage, and to determine blood ketone concentrations. Hypothesis: Oral consumption of a ketone beverage before moderate intensity exercise will be safe and well-tolerated, and will raise blood ketones among subjects with a LC-FAOD to concentrations similar to that reported in the literature among normal healthy subjects.