Effects of ketone supplements on recovery in ultra-endurance cycling

Exploring the Role of Intermittent Exogenous Ketosis on Physical and Mental Fatigue During Ultra-endurance Performance

Not applicable Interventional KU Leuven · NCT06965491

This study tests if taking ketone supplements can help ultra-endurance cyclists recover better after a long race.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years to 59 Years
SexAll
SponsorKU Leuven Academic / other
Locations1 site (Leuven, Vlaams-Brabant)
Trial IDNCT06965491 on ClinicalTrials.gov

What this trial studies

This study investigates how oral ketone ester supplementation affects physical and mental recovery in athletes participating in a multi-day cycling stage race. Participants will engage in an 8-day simulated stage race followed by a field study during the Absa Cape Epic. They will consume either a ketone ester or a placebo drink immediately after each stage and before bed, while various performance and recovery metrics will be measured. The goal is to understand the role of intermittent exogenous ketosis in reducing fatigue and enhancing performance during ultra-endurance events.

Who should consider this trial

Good fit: Ideal candidates are experienced cyclists who have been training consistently for at least one year and are preparing for the Absa Cape Epic.

Not a fit: Patients who follow a ketogenic diet or have metabolic disorders may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help athletes improve their recovery and performance during multi-day endurance events.

How similar studies have performed: While the effects of ketosis on endurance performance have been explored, this specific approach of using ketone esters in a multi-day cycling context is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* have been cycling consistently for at least 1 year before entry into the study
* have been cycling for a minimum of 7 hours per week for the 6 months leading up to the study
* additional for the field study: valid entry to the 2025 edition of the Absa Cape Epic
* non-smoker

Exclusion Criteria:

* Do not follow a ketogenic diet or low-carbohydrate diet
* Have any metabolic or auto-immune disease that will influence their metabolism
* Take medication or supplements that is known to affect ketone supplement metabolism
* suffering from a recurring injury or illness from which they have not fully recovered that is a contr-indication to perform high-intensity exercise
* Unable to finish each stage
* Women: if they are pregnant or breastfeeding

Where this trial is running

Leuven, Vlaams-Brabant

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Exogenous KetosisEndurance Cycling PerformanceFatigueMuscle, HeartFatigue, Mentalultra-endurancecyclingphysiological strain
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.