High Altitude Hypoxia, Exercise
Conditions
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.
Interventions
DIETARY_SUPPLEMENTKetone Monoester (KME)
0.6 g KME per kg body mass; \[R\]-3-hydroxybutyl \[R\]-3-hydroxybutyrate. (Delta G Ketone, TΔS, Oxford).
DIETARY_SUPPLEMENTPlacebo
Inert, calorie-free placebo drink that is taste-matched to the ketone monoester supplement
Sponsors
McMaster University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
| 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. |
| 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. |
Countries
Canada, United States
Outcome results
None listed