Ketosis
Conditions
Brief summary
Ketone ester supplementation has become increasingly popular as an athletic supplement. However, the metabolic effects of these supplements on exercise performance are controversial. One potential reason for lack of an ergogenic benefit could be the effects of ketone bodies on other bodily systems, such as the sympathetic nervous system. During exercise and stress the body increases the activity of the sympathetic nervous system. This causes blood vessels to constrict (get smaller) and can increase blood pressure. Studies have shown that ketone bodies can suppress the sympathetic nervous system in mice. Additionally, ketone ester supplementation can reduce blood pressure in healthy adults. In humans, direct measures of sympathetic activity are usually made from sympathetic outflow to muscle, also called muscle sympathetic nerve activity (MSNA). Using a ketone ester supplement, the investigators plan to measure blood pressure and sympathetic outflow to muscle at rest and during handgrip exercise and a mathematical task stress test to investigate the effect of ketones on neuro-cardiovascular stress responses.
Interventions
DIETARY_SUPPLEMENTD-beta-hydroxybutyrate
Drink containing D-beta-hydroxybutyrate administered at a dose of 395 mg/kg.
DIETARY_SUPPLEMENTPlacebo
Isocaloric flavored water with medium-chain triglyceride oil.
Sponsors
University of Guelph
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Masking description
Double-blind
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* 18 to 40 years of age * Healthy, free of known cardiovascular, metabolic, or musculoskeletal disease
Exclusion criteria
* History of smoking (within 3 months), diagnosed cardiovascular or metabolic disease, recent musculoskeletal injury preventing handgrip exercise, prescription of chronic medications other than oral contraceptives. * Current or recent (within 6 months) use of ketone ester supplementation or participation in a ketogenic diet. * Inability to abstain from drugs, caffeine, alcohol, or strenuous physical activity prior to the study visit.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscle sympathetic nerve activity | Baseline - Immediately before active and control interventions | Microneurography of fibular nerve |
| Blood pressure | Baseline - Immediately before active and control interventions | Finger plethysmography |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Forearm blood flow | Baseline - Immediately before active and control interventions | Brachial artery Doppler ultrasound |
Countries
Canada
Outcome results
None listed