The Effect of Olive Leaf Extract Supplementation on Training-induced Skeletal Muscle Functional and Molecular Adaptations in Healthy Volunteers (OLE_Training_1)
July 22, 2026 updated by: Nicolas Place, University of Lausanne
The goal of this study is to investigate the effect of combining olive leaf extract supplementation with endurance training (moderate intensity continuous training or sprint interval training).
We hypothesize that OLE supplementation during training, as compared to training alone with placebo, will translate into better performance outcomes.
More specifically, we hypothesize that the additional benefits of OLE supplementation on performance will be mediated by improved mitochondrial characteristics in skeletal muscle and increased neural activation.
Study Overview
Status
Not yet recruiting
Conditions
Intervention / Treatment
Detailed Description
Maximal exercise capacity (VO2peak) predicts cardiovascular risk and all-cause mortality.
Regular moderate to vigorous physical activity, a key determinant of VO2peak, is essential for an optimal health status of the general population.
Thus, strategies that accentuate the health benefits of exercise may have considerable therapeutic benefits.
Skeletal muscle Ca2+ handling is a primary determinant of exercise capacity.
The regulation of skeletal muscle contraction by Ca2+ is coupled to mitochondrial energy production through a mechanism involving transport across the inner mitochondrial membrane by the mitochondrial Ca2+ uniporter (MCU).
Ca2+ entry in the mitochondrial matrix controls Ca2+ -sensitive enzymes, including pyruvate dehydrogenase (PDH) activity, a rate-limiting enzyme for glycolysis.
Olive leaf extract (OLE) contains ~40% of the natural polyphenol oleuropein and is a potent activator of MCU in skeletal muscle with anti-inflammatory and antioxidant properties.
The present study will be a double-blind, randomized, placebo-controlled, parallel study in healthy young individuals (18-45 years) consisting of a 3-week endurance training (either moderate intensity continuous training or sprint interval training) period combined with OLE or placebo intake.
We will examine the impact of OLE supplementation on maximal exercise capacity, knee extensor neuromuscular function, muscular and blood adaptations.
The results of this study will elucidate whether OLE supplementation improves fitness parameters and the molecular mechanisms regulating these adaptations.
Study Type
Interventional
Enrollment (Estimated)
60
Phase
- 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
- Name: Nicolas Place, PhD
- Phone Number: +41216923806
- Email: nicolas.place@unil.ch
Study Locations
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Lausanne, Switzerland, 1015
- Bâtiment Synathlon, quartier UNIL-Centre
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Contact:
- Nicolas Place, PhD
- Phone Number: +41216923806
- Email: nicolas.place@unil.ch
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Sub-Investigator:
- Javier Botella, PhD
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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:
- Being between 18 and 45 years old
- Being healthy (assessed through the PAR-Q questionnaire).
- Being physically active, but not involved in any structured training program
- Being available for the study period.
Exclusion Criteria:
- If a participant answers positively to any YES/NO question in the PAR-Q health questionnaire. For questions requiring a precision, any positive answer will be reviewed by a medical doctor, who will determine the inclusion/exclusion of the participant.
- Having allergy to xylocaine
- Being pregnant.
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: Parallel Assignment
- Masking: Triple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
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Experimental: Sprint interval training group (SIT group)
The model of sprint interval training (SIT) consists of four to six 30 s all-out cycling bouts on a cycle ergometer, with 4 min rests between tests.
Three sessions will be performed per week for three weeks.
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A capsule containing 250 mg of an olive leaf extract preparation will be swallowed with a glass of water daily for 21 days.
A capsule containing 336 mg of cellulose microcrystalline will be swallowed with a glass of water daily for 21 days.
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Experimental: Moderate intensity continuous training (MICT group)
The moderate intensity continuous training (MICT) consists of 40 to 60 min cycling on a cycle ergometer at 50% of the maximal aerobic power output.
Three sessions will be performed per week for three weeks.
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A capsule containing 250 mg of an olive leaf extract preparation will be swallowed with a glass of water daily for 21 days.
A capsule containing 336 mg of cellulose microcrystalline will be swallowed with a glass of water daily for 21 days.
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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maximal aerobic power
Time Frame: before and after the three-week training period
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maximal power (in watts) measured during a graded exercise to failure
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before and after the three-week training period
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Maximal oxygen uptake
Time Frame: before and after the three-week training period
|
maximal oxygen uptake (ml/min/kg) measured during a graded exercise until failure
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before and after the three-week training period
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Submaximal heart rate and power
Time Frame: before and after the three-week training period
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heart rate and power measured during submaximal cycling exercise
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before and after the three-week training period
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Knee extensor neuromuscular function
Time Frame: before and after the three-week training period
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maximal voluntary contraction force and maximal voluntary activation level
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before and after the three-week training period
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Collaborators and Investigators
This is where you will find people and organizations involved with this study.
Sponsor
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
- Zanou N, Dridi H, Reiken S, Imamura de Lima T, Donnelly C, De Marchi U, Ferrini M, Vidal J, Sittenfeld L, Feige JN, Garcia-Roves PM, Lopez-Mejia IC, Marks AR, Auwerx J, Kayser B, Place N. Acute RyR1 Ca2+ leak enhances NADH-linked mitochondrial respiratory capacity. Nat Commun. 2021 Dec 10;12(1):7219. doi: 10.1038/s41467-021-27422-1.
- Gherardi G, Weiser A, Bermont F, Migliavacca E, Brinon B, Jacot GE, Hermant A, Sturlese M, Nogara L, Vascon F, De Mario A, Mattarei A, Garratt E, Burton M, Lillycrop K, Godfrey KM, Cendron L, Barron D, Moro S, Blaauw B, Rizzuto R, Feige JN, Mammucari C, De Marchi U. Mitochondrial calcium uptake declines during aging and is directly activated by oleuropein to boost energy metabolism and skeletal muscle performance. Cell Metab. 2025 Feb 4;37(2):477-495.e11. doi: 10.1016/j.cmet.2024.10.021. Epub 2024 Nov 26.
- Lanfranchi C, Moreno-Asso A, Horstman AMH, Mistro S, Migliavacca E, Cominetti O, Stolte J, Metairon S, Hermant A, Pedersen AL, Dayon L, De Marchi U, Feige JN, Zanou N, Place N. Oleuropein-based olive leaf extract enhances muscle mitochondrial bioenergetics response to moderate - but not maximal - intensity exercise in humans. J Physiol. 2026 May;604(10):3802-3824. doi: 10.1113/JP290316. Epub 2026 Apr 14.
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)
September 1, 2026
Primary Completion (Estimated)
December 31, 2028
Study Completion (Estimated)
December 31, 2029
Study Registration Dates
First Submitted
July 17, 2026
First Submitted That Met QC Criteria
July 22, 2026
First Posted (Actual)
July 27, 2026
Study Record Updates
Last Update Posted (Actual)
July 27, 2026
Last Update Submitted That Met QC Criteria
July 22, 2026
Last Verified
July 1, 2026
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- 2026-00654
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
UNDECIDED
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
No
Studies a U.S. FDA-regulated device product
No
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