The Effects of Acute Ketone Monoester Supplementation on Exercise Efficiency and the Influence of Dose and Intensity

Study Overview
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Brief Summary
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Diet can alter blood ketone levels and this in turn may affect exercise capacity. This study will determine if the acute ingestion of a ketone supplement alters cycling exercise efficiency. Participants will perform three trials in a randomized order. Each trial will involve an incremental exercise protocol on a stationary cycle ergometer to volitional fatigue. Participants will ingest either a high or low dose of a ketone supplement or a taste-matched placebo drink prior to exercise. Blood samples will be obtained to assess selected metabolic responses. This study will provide information regarding the effect of ketone supplementation on exercise efficiency.

Detailed Description
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This study will determine if the acute ingestion of a ketone supplement alters cycling exercise efficiency. Trained participants with cycling experience will be recruited. Participants will perform three trials in a randomized order. Each trial will involve a 3-minute warm-up followed by an incremental ramp test. The ramp will initially consist of three, 5-minute stages performed at relative workloads corresponding to 75%, 100%, and 125% of individual ventilatory threshold intensity. This will be followed by a further incremental ramp test to volitional fatigue. Participants will ingest either a high or low dose of a ketone supplement or a taste-matched placebo drink prior to exercise using a randomized, double-blind crossover design. Diet prior to exercise will be standardized between trials for a given participant. Blood samples will be obtained to assess selected metabolic responses. This study will provide information regarding the effect of ketone supplementation on exercise efficiency.

Official Title
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The Effects of Acute Ketone Monoester Supplementation on Exercise Efficiency and the Influence of Dose and Intensity

Conditions
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Exercise, Ketosis

Intervention / Treatment
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* Dietary Supplement: Ketone monoester
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Be habitually consuming ≥50 g/d of carbohydrate (i.e., not following a ketogenic diet). Be engaged in endurance-type exercise >3h/wk. Have an estimated VO2peak of ≥90% for age and sex as estimated by an online calculator found at www.worldfitnesslevel.org. Exclusion Criteria: Experiencing a condition that might preclude safe participation in physical activity and exercise, as determined by answering Yes to any question on Page 1 of the Canadian Society for Exercise Physiology Get Active Questionnaire.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ketone higher dose<br>An acute bout of exercise performed after the ingestion of a commercial supplement intended to provide  0.6 g of ketone monoester per kg body mass of the participant. | Dietary Supplement: Ketone monoester<br>* A commercial liquid ketone monoester supplement.<br>|
| Experimental: Ketone lower dose<br>An acute bout of exercise performed after the ingestion of a commercial supplement intended to provide  0.3 g of ketone monoester per kg body mass of the participant. | Dietary Supplement: Ketone monoester<br>* A commercial liquid ketone monoester supplement.<br>|
| Placebo Comparator: Control<br>An acute bout of exercise performed after the ingestion of a taste-matched placebo supplement. | Other: Placebo<br>* A liquid placebo that is taste-matched to the ketone monoester supplement.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exercise efficiency | Power output expressed relative to pulmonary oxygen uptake to determine cycling economy in watt per litre of oxygen per minute | Continuous measurement made over each of three, 5-minute consecutive stages of an incremental cycle exercise test at relative workloads corresponding to 75%, 100%, and 125% of individual ventilatory threshold intensity | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | Mean heart rate | Continuous measurement made over each of three, 5-minute consecutive stages of an incremental cycle exercise test at relative workloads corresponding to 75%, 100%, and 125% of individual ventilatory threshold intensity | 
| Rating of perceived exertion | Rating of perceived exertion measured using a 6-20 scale | Measurement made at the end of each of three, 5-minute consecutive stages of an incremental cycle exercise test at relative workloads corresponding to 75%, 100%, and 125% of individual ventilatory threshold intensity | 
| Ketone body content in venous blood | Mixed venous blood content of the ketone body beta-hydroxybutyrate | Measurement made immediately prior to exercise | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Efficiency