The Effects of Ketone Supplements With Carbohydrates on Cycling Performance Above Lactate Threshold

November 3, 2025 updated by: University of Oklahoma

The Effects of R-1,3-Butanediol With Carbohydrate Supplementation on Cycling Performance Above Lactate Threshold

The goal of this clinical trial is to determine whether a ketone supplement with carbohydrates extends time to fatigue during cycling compared with a carbohydrate-only supplement in healthy, trained cyclists aged 18-55. The main questions it aims to answer are:

Is the time to fatigue increased with ketone supplementation and carbohydrates compared to carbohydrates alone? Will ketone supplementation with carbohydrates produce lower blood lactate concentrations compared to carbohydrates alone?

Participants will:

  • Perform a staged maximal cycling exercise test on a stationary bicycle.
  • Finger prick to obtain a drop of blood for lactate measurements.
  • Wear a mask connected to a metabolic cart to measure breath contents.
  • Perform a cycling exercise test to fatigue for at least one hour.
  • Consume either a ketone supplement with carbohydrates or a carbohydrate supplement during the exercise at least 4 times.
  • Finger prick to obtain a drop of blood to measure blood lactate, ketones, and glucose.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

The significance of this study is to address gaps in the literature by investigating the combined effects of R-1,3-Butanediol and carbohydrate supplementation on cycling performance during steady-state exercise above the lactate threshold. Participants include:

  1. Trained cyclists ages 18-55

    1. ≥ 6 hours of cycle training per week.
    2. Above average VO2max for their age range per ACSM guidelines.
  2. The sample is drawn from the University of Oklahoma, local cycling events in Oklahoma, and local bicycle shops.

There will be a total of three visits, lasting approximately one hour and separated by at least 7 days. The protocol begins with a familiarization visit, during which participants complete a maximal graded exercise test. They are instructed to be at least 4 hours postabsorptive and not complete strenuous exercise within 24 hours of the initial visit, and each participant signs an informed consent form, fills out a POMS questionnaire, and exercise history questionnaire (PAR-Q). Participants' height and weight were recorded, and their bicycles will be connected to the cycling trainer or will use the Zwift One stationary bicycle. To determine VO2 max and lactate threshold, a continuous incremental cycling test will be performed. The test begins at 1 watt per kilogram of body weight and increases 0.5 watts per kilogram of body weight every 3 minutes until two of the following were reached: volitional fatigue, inability to maintain cadence within 10 rpm of their preferred cadence, maximal heart rate within 10 bpm of age-predicted max heart rate, or respiratory exchange ratio greater than 1.10 The intent is to provide insights into metabolic and performance responses beyond traditional exercise intensities. The findings could inform endurance athletes and coaches on nutritional strategies for sustaining performance during high-intensity efforts.The study aims to investigate the performance effects of a ketone supplement (R-1,3-Butanediol) with carbohydrate supplementation on cycling performance above the lactate threshold. It aims to determine whether time to fatigue will be affected and if blood lactate concentrations will decrease due to ketone supplementation. Hypotheses include:

Time to fatigue is increased with ketone supplementation and carbohydrates compared to carbohydrates alone.

Ketone supplementation with carbohydrates will produce lower blood lactate concentrations compared to carbohydrates alone.

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Early Phase 1

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

  • Name: Rebecca Larson, Ph.D.
  • Phone Number: 405-325-5211
  • Email: rdlarson@ou.edu

Study Contact Backup

Study Locations

  • United States
    • Oklahoma
      • Norman, Oklahoma, United States, 73019
        • University of Oklahoma
        • Contact:

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Highly trained males and females
  • Ages 18-55
  • Greater than or equal to six hours of cycling training per week
  • Participants from the University of Oklahoma, Oklahoma cycling teams, and local cycling races in Oklahoma.

Exclusion Criteria:

  • Cardiovascular disease
  • Respiratory disease
  • Gastrointestinal disease
  • Metabolic disease
  • Kidney disease
  • Neurological disease
  • 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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Ketone supplementation with carbohydrates
Dietary supplement: Ketone supplementation
30-gram carbohydrate beverage with 5 grams of R-1,3-Butanediol every 30 minutes of experimental visit
Dietary supplement: Carbohydrate
30-gram carbohydrate beverage with bitter flavoring
Other Names:
  • Dextrose
Placebo Comparator: Carbohydrate supplement only
Dietary supplement: Carbohydrate
30-gram carbohydrate beverage with bitter flavoring
Other Names:
  • Dextrose

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Time to fatigue
Time Frame: Through study completion, an average of 2 weeks.
Through study completion, an average of 2 weeks.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Blood lactate
Time Frame: Through study completion, an average of 2 weeks.
Through study completion, an average of 2 weeks.
Blood Glucose
Time Frame: Through study completion, an average of 2 weeks.
Through study completion, an average of 2 weeks.
Beta-hydroxybutyrate levels
Time Frame: Through study completion, an average of 2 weeks.
Using a finger prick to obtain a drop of blood to measure beta-hydroxybutyrate levels in the blood.
Through study completion, an average of 2 weeks.

Collaborators and Investigators

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

Sponsor

University of Oklahoma

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Estimated)

November 17, 2025

Primary Completion (Estimated)

March 9, 2026

Study Completion (Estimated)

May 3, 2026

Study Registration Dates

First Submitted

October 28, 2025

First Submitted That Met QC Criteria

November 3, 2025

First Posted (Estimated)

November 4, 2025

Study Record Updates

Last Update Posted (Estimated)

November 4, 2025

Last Update Submitted That Met QC Criteria

November 3, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 18836

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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