The Effect of Acute Ketone Monoester Supplementation on Glucose Oxidation During Exercise (KETONE)

September 19, 2025 updated by: Maastricht University Medical Center

The Effect of Acute Ketone Monoester Supplementation on Glucose Oxidation During Exercise Performed With High Rates of Carbohydrate Ingestion in Trained Cyclists

The purpose of this study is to examine the effect of exogenous ketone body supplementation on carbohydrate metabolism during exercise. In a randomized, crossover, and double-blind study, 20 endurance trained adult males and females aged 18-50 years, will ingest carbohydrates with either a ketone monoester supplement before and throughout a 3-hour exercise session or carbohydrates with a flavour-matched ketone-free placebo. The main aim of this study is to compare the exogenous carbohydrate oxidation rates during exercise between the ketone monoester and placebo conditions.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
27

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Netherlands
    • Limburg
      • Maastricht, Limburg, Netherlands, 6229ER
        • Recruiting
        • Maastricht University Medical Center+
        • Contact:
        • Sub-Investigator:
          • Philippe Pinckaers, MSc

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18-50 years of age
  • Trained cyclist/triathlete (VO2peak > 55 ml/kg/min for males and >48 ml/mg/min for females)
  • Healthy as per medical history and investigator's/physician's judgement
  • Having given written informed consent

Exclusion Criteria:

  • Use of medication that could impact study outcomes and/or interfere with the expected mechanism of action of ketone supplements (e.g. Chronic use of gastric acid suppressing medication, statins, corticosteroids)
  • Smoking
  • Diagnosed acute or chronic medical conditions that, in the opinion of the investigator, could impact study outcomes (e.g. Diabetes mellitus)
  • Diagnosed musculoskeletal disorders
  • Adhering to a carbohydrate restrictive diet
  • Participation in another study at the same time
  • Blood donation in the 2 months before the first experimental trial
  • Plasma donation in the 2 weeks before the first experimental trial
  • Males: VO2peak <55 ml/min/kg body mass
  • Females: VO2peak <48 ml/min/kg body mass
  • Females: pregnancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: CHO+KETONE
Interventional drink with glucose + ketone monoester
Dietary supplement: CHO+KETONE
Sports drink containing glucose and ketone mono-esters
Placebo Comparator: CHO+PLACEBO
Placebo drink with glucose + placebo
Dietary supplement: CHO+PLACEBO
Sports drink containing glucose and placebo

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Exogenous carbohydrate oxidation rate
Time Frame: Acute:during 3 hours of exercise
Exogenous carbohydrate oxidation rate during exercise measured by 13C enrichment in breath. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Endogenous carbohydrate disappearance rate
Time Frame: Acute:during 3 hours of exercise
Endogenous carbohydrate disappearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Exogenous carbohydrate disappearance rate
Time Frame: Acute:during 3 hours of exercise
Exogenous carbohydrate disappearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Total carbohydrate disappearance rate
Time Frame: Acute:during 3 hours of exercise
Total carbohydrate disappearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Exogenous carbohydrate appearance rate
Time Frame: Acute:during 3 hours of exercise
Exogenous carbohydrate appearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Endogenous carbohydrate appearance rate
Time Frame: Acute:during 3 hours of exercise
Endogenous carbohydrate appearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Total carbohydrate appearance rate
Time Frame: Acute:during 3 hours of exercise
Total carbohydrate appearance rate during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Plasma glucose enrichments during exercise
Time Frame: Acute:during 3 hours of exercise
Plasma glucose enrichments during exercise measured by stable isotope tracer methodology. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Total carbohydrate oxidation
Time Frame: Acute:during 3 hours of exercise
Total carbohydrate oxidation during exercise, measured indirectly by using traditional stoichiometric calculations of carbohydrate oxidation. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Blood parameters
Time Frame: Acute:during 3 hours of exercise
Plasma glucose, insulin, glycerol, free fatty acids, and ketone body concentrations (including area under the curve) following drink ingestion. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise
Exercise economy during cycling
Time Frame: Acute:during 3 hours of exercise
Exercise economy during the exercise trial. CHO+KETONE vs CHO+PLACEBO condition, will be determined based on the amount of work performed during cycling (workload), and the amount of energy expenditure as measured by indirect calorimetry.
Acute:during 3 hours of exercise
Exercise heart rate
Time Frame: Acute:during 3 hours of exercise
Heart rate during exercise. CHO+KETONE vs CHO+PLACEBO condition
Acute:during 3 hours of exercise

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Maastricht University Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 4, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 11, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 18, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 24, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 24, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 19, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • METC 23-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Data will be made available upon request

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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