The Effects of Exogenous Ketosis on Ultra-endurance Recovery and Performance

NCT06965491 | Completed DMC

• 1 other identifier: S68178
• Study Type: interventional
• Target: 18
• Locations: 1 country
• Sites: 1

Brief Summary

The study aims to investigate the effects of post-exercise and pre-sleep ketosis via oral ketone ester supplementation on physical and mental recovery during a multi-day cycling stage race.

Conditions

Exogenous Ketosis; Endurance Cycling Performance; Fatigue; Muscle, Heart; Fatigue, Mental

Keywords

ultra-endurance; cycling; physiological strain; mental fatigue

Outcome Measures

Primary Outcomes (10)

• Muscle soreness

  Visual analog scale (0-10) How sore does you leg muscles feel? The VAS was used as a subjective measure of muscle soreness

  During the intervention

• Physical stress

  RESTQ-76 sport questionnaire was used to assess the stress-recovery balance

  pre-intervention and 1 day after the intervention

• Hydration status

  Before every stage, the participants provided a urine sample in a cup. A urine-specific refractometer (Atago) was used to determine their hydration status

  Baseline, During the intervention and 1 day after the intervention

• Cognitive function: reaction time

  CANTAB test battery reaction time test was used to determine reaction time in milliseconds.

  Pre-intervention, day 2, 4 and 8 of the intervention

• Cognitive function: rapid visual processing

  CANTAB test battery rapid visual processing test was used to assess their susceptibility to false alarms

  Pre-intervention, day 2, 4 and 8 of the intervention

• Cognitive function: swm

  CANTAB spatial working memory test was used to access executive function; the main outcome measure used was the number of errors

  Pre-intervention, day 2, 4 and 8 of the intervention

• Sleep Duration

  Fitbit inspire 3 was used to measure sleep duration (hours:minutes:seconds)

  1 week prior to racing and during the race

• Sleep: REM

  The Fitbit Inspire 3 was used to measure the total duration of rapid eye motion (REM)sleep during each night for the duration of the study. The REM sleep phase will be analysed in minutes

  1 week prior to racing and during the race

• Sleep: Non-REM

  The Fitbit Inspire 3 will be used to determine the NON-REM sleep phase for each night in minutes

  1 week prior to racing and during the race

• Sleep: WASO

  The FITBIT inspire 3 will be used to measure wake after sleep onset in minutes for each night

  1 week prior to racing and during the race

Secondary Outcomes (7)

• Mechanical efficiency

  pre-intervention and 1 day after the intervention

• Time trial performance

  pre-intervention and 1 day after the intervention

• Appetite

  pre-intervention, during the intervention, 1 day after the intervention

• Macronutrient intake

  baseline, during the intervention

• Total energy intake

  baseline, during the intervention

Study Arms (2)

Control group

PLACEBO COMPARATOR

Intervention: 8-day multistage mountain bike race/simulation Dietary intervention: placebo supplement (oral supplement containing: 16.4 grams of medium chained triglycerides, 1mM of sucrose octaacetate and water)

Dietary Supplement: Placebo Supplement

Experimental group

EXPERIMENTAL

Intervention: 8-day multistage mountain bike race/simulation Dietary intervention: ketone ester supplement (25 grams of pure R-(3)-hydroxybutyl-(R)-3-hydroxybutyrate ketone monoester drink)

Dietary Supplement: Ketone ester supplement

Interventions

Placebo Supplement DIETARY_SUPPLEMENT

Placebo supplement: Oral supplement containing: 16.4 grams of medium chained triglycerides, 1mM or sucrose octaacetate and water

Control group

Ketone ester supplement DIETARY_SUPPLEMENT

Ketone ester supplement Oral supplement containing: 25 grams of pure (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate ketone monoester drink

Experimental group

Eligibility Criteria

• Age: 18 Years - 59 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• KU Leuven: lead
• University of Stellenbosch: collaborator

Study Sites (1)

KU Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

Location

MeSH Terms

Conditions

Fatigue; Mental Fatigue

Condition Hierarchy (Ancestors)

Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavioral Symptoms; Behavior

Study Officials

• Chiel Poffé

  KU Leuven

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Participants and investigators are blinded from the experimental condition (KE or CON). Supplements are provided in non transparent tubes and the control supplement is identical in taste and viscosity to the ketone supplement.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: Riders will be paired matched and randomly assigned to either the ketone ester supplementation (KE) group or the control group (CON) which will receive an isocaloric taste-matched placebo

Study Record Dates

• First Submitted: October 4, 2024
• First Posted: May 11, 2025
• Study Start: March 1, 2024
• Primary Completion: March 27, 2025
• Study Completion: October 30, 2025
• Last Updated: February 20, 2026

Record last verified: 2025-05

Locations

BE (1)