Overview
Ketone bodies are produced by the liver during periods of food scarcity or severe carbohydrate restriction. Blood ketones are an alternative fuel source used by the brain, heart, and skeletal muscle during periods of fasting. Further, ketones bodies act as a signalling molecule that have pleiotropic effects that upregulate cellular stress-resistance pathways throughout the body.
Oral supplements containing exogenous ketones have recently become available and represent a novel tool for increasing plasma ketone bodies without the need for dietary restriction. Early evidence suggests that oral ketone supplements may enhance cerebral blood flow and improve cognition. However, the dose-dependent effects of a single ketone supplement on cerebral blood flow and cognition in young adults is currently unknown.
The purpose of this study is to characterize the effects of ingesting a high versus low dose of an oral ketone monoester on cerebral blood flow, circulating blood markers, and cognition in young adults.
As an exploratory aim, this study will investigate how oxygen uptake kinetics during submaximal exercise are impacted 2 hours after ingestion of a ketone supplement. Recent findings indicate that ketone supplementation may impair exercise performance due to the physiological stress (i.e., pH disturbances) imposed by an acute ketone dose. Delaying exercise onset by 2 hours after ingestion of a ketone supplement may enhance oxygen kinetics in a dose-dependent manner.
Eligibility
Inclusion Criteria:
- Between the ages of 18 and 35
Exclusion Criteria:
- Presence of obesity (body mass index > 30 kg/m^2)
- Presence of known cardiovascular disease
- Presence of type 2 diabetes
- History of cardiovascular events requiring hospitalization (i.e., heart attack)
- History of concussion(s) with persistent symptoms
- Currently following a ketogenic diet and/or taking ketone body supplements