Ketone supplement effects on brain blood flow during exercise at high altitude

The Effect of Ketone Monoester Supplementation and High Altitude on Exercising Cerebral Blood Flow

Not applicable Interventional McMaster University · NCT07063732

This trial will test whether a single dose of a ketone monoester supplement changes when people reach their ventilatory threshold and how blood speed in brain arteries responds during maximal exercise at low and high altitude.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment14 (estimated)
Ages18 Years to 35 Years
SexAll
SponsorMcMaster University Academic / other
Locations2 sites (Bishop, California and 1 other locations)
Trial IDNCT07063732 on ClinicalTrials.gov

What this trial studies

Healthy adult members of a research expedition will receive a single acute dose of ketone monoester (0.6 g/kg) or a placebo before performing a maximal exercise test at both low altitude and at the Barcroft Research Station high-altitude site. The study measures the ventilatory threshold during exercise and the subsequent blood velocity in cerebral arteries using noninvasive ultrasound/Doppler methods. Participants must meet strict health criteria (no major cardiopulmonary or kidney disease, non-smokers, BMI ≤30, not on most prescription medications, not following a ketogenic diet). The crossover-like design compares responses after ketone versus placebo to see if ketone ingestion alters ventilatory and cerebral hemodynamic responses to maximal exercise in hypoxia.

Who should consider this trial

Good fit: Ideal candidates are healthy adult expedition team members traveling to the Barcroft Research Station who are BMI ≤30, non-smokers, not pregnant, not following a ketogenic diet, and not taking prescription medications (oral contraceptives allowed).

Not a fit: People with a history of heart, lung, blood vessel, or kidney disease, current smokers, those with BMI >30, on prescription medications, pregnant individuals, or people already on ketogenic diets or supplements are unlikely to be eligible or benefit from this protocol.

Why it matters

Potential benefit: If successful, this could point to a simple nutritional option to help preserve brain blood flow and modify breathlessness timing during intense exercise at high altitude.

How similar studies have performed: Prior small studies have shown ketone esters alter metabolism and sometimes affect exercise performance or brain metabolism, but applying them to cerebral blood flow responses at high altitude is relatively novel and not well established.

Eligibility criteria

Show full inclusion / exclusion criteria
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

Where this trial is running

Bishop, California and 1 other locations

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions High Altitude HypoxiaExercise
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.