Ketone Monoester Supplements, High Altitude, and Brain Blood Flow During Exercise

Not Applicable

Recruiting

• Conditions: High Altitude Hypoxia; Exercise

• Registration Number: NCT07063732
• Lead Sponsor: McMaster University

Brief Summary

The purpose of this trial is to investigate the effect of acute ketone monoester ingestion (0.6 g KME/kg body weight) on the occurrence of the ventilatory threshold and the subsequent response of blood velocity in cerebral arteries during a maximal exercise test at low altitude and high altitude.

Detailed Description

Not available

Study Timeline

• Study Start: 2025-05-28
• Study First Submitted: 2025-05-28
• Status Verified: 2025-07
• Study First Submitted QC: 2025-07-02
• Last Update Submitted: 2025-07-02
• Study First Posted: 2025-07-14
• Last Update Posted: 2025-07-14
• Primary Completion: 2025-08-31
• Study Completion: 2025-08-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 14

Inclusion Criteria

• Must be a member of the research expedition team travelling to the Barcroft Research Station in White Mountain California

Exclusion Criteria

• BMI > 30
• No prescribed medications (oral contraceptives excluded)
• History of smoking
• Currently following a ketogenic diet or consuming exogenous ketogenic supplements
• History of heart, lung, blood vessel, or kidney disease
• Currently pregnant

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Cerebral Blood Velocity	3 hours	Transcranial Doppler ultrasound will be used to measure blood velocity in the middle cerebral artery and posterior cerebral artery. Location of measurements will remain consistent within participants.

Secondary Outcome Measures

Name	Time	Method
Cardiac Output	3 hours	Cardiac output (L/min) will be measured using a non-invasive cardiac output monitor (Physioflow). The monitor uses signal morphology impedance cardiography to determine cardiac output.
Blood Pressure	3 hours	Mean arterial pressure (mmHg) will be measured via a brachial cuff placed on the upper arm.
Ventilatory Threshold	3 hours	Ventilatory threshold (VT) will be calculated based on previously described methods (Gaskill et al., 2001).
End-Tidal Gases	3 hours	End-tidal oxygen (PETO2) (mmHg) and carbon dioxide (PETCO2) (mmHg) will be collected using a metabolic cart.
Rate of Oxygen Consumption and Carbon Dioxide Production	3 hours	Rate of oxygen consumption (VO2) (mL/min) and carbon dioxide production (VCO2) (mL/min) will be collected using a metabolic cart.
Ventilation	3 hours	Ventilation (Ve) (L/min) will be collected using a metabolic cart.
Blood Lactate and Beta-Hydroxybutyrate	3 hours	Capillary blood will be obtained via finger prick using a lancing device to measure concentrations of blood lactate (mmol/L) and beta-hydroxybutyrate (mmol/L) using a handheld metabolite analyzer.
Peak Work Rate (Maximal Exercise Test)	3 hours	The maximum wattage (W) achieved by the participant during the maximal exercise test will be recorded.

Trial Locations

Locations (2)

Barcroft Research Station; 🇺🇸 Bishop, California, United States

University of Guelph; 🇨🇦 Guelph, Ontario, Canada