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NCT Number: NCT07224282

The Effects of Ketone Supplements With Carbohydrates 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.

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Key information

Conditions

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

About this study

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:

  • Trained cyclists ages 18-55
  • ≥ 6 hours of cycle training per week.
  • Above average VO2max for their age range per ACSM guidelines.
  • 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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Ketone Supplementation

Dietary Supplement

30-gram carbohydrate beverage with 5 grams of R-1,3-Butanediol every 30 minutes of experimental visit

Carbohydrate

Dietary Supplement

30-gram carbohydrate beverage with bitter flavoring

Other names: Dextrose

Primary outcomes

  1. Time to fatigue

    Time frame: Through study completion, an average of 2 weeks.

Secondary outcomes

  1. Blood lactate

    Time frame: Through study completion, an average of 2 weeks.

  2. Blood Glucose

    Time frame: Through study completion, an average of 2 weeks.

  3. 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.

Study contacts

Contact information is provided by the study sponsor or research team.

Cole Connell

CONTACT

[email protected]

405-628-3525

Rebecca Larson, Ph.D.

CONTACT

[email protected]

405-325-5211

Sponsors and collaborators

Lead sponsor

University of Oklahoma

Other

Registry information

Official study title

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

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Nov 4, 2025
Registry last updated
Nov 4, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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