Tea extract plus protein for faster knee muscle recovery after downhill jogging

The Influence of Tea Extract on Maximal Voluntary Knee Contraction After 30 Minutes of Downhill Jogging: a Randomized, Double-blind, Placebo-controlled Study

NA · University of Fribourg · NCT07113405

We will test whether adding tea extract to a protein drink helps healthy adults aged 18–40 recover knee muscle strength faster after downhill jogging.

Quick facts

PhaseNA
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 40 Years
SexAll
SponsorUniversity of Fribourg (other)
Locations1 site (Fribourg, Canton of Fribourg)
Trial IDNCT07113405 on ClinicalTrials.gov

What this trial studies

Healthy adults aged 18–40 are randomly assigned, in a double-blind design, to one of three groups: protein plus tea extract, protein alone, or placebo. The study lasts five days and requires five in-person laboratory visits. On day one participants jog downhill for 30 minutes to produce muscle strain, and each day researchers collect fingertip blood samples, perform thigh ultrasound, measure pain tolerance, test muscle strength, and evaluate muscle function. Only the regeneration product differs between groups so recovery can be compared directly.

Who should consider this trial

Good fit: Ideal participants are healthy adults 18–40 with no food allergies or major medical issues who can safely perform downhill jogging and attend five lab visits in Fribourg.

Not a fit: People with food allergies, current lower-extremity or serious back injuries, cardiovascular disease, or those taking blood thinners or anti-inflammatory medications, as well as individuals outside the 18–40 age range, are unlikely to benefit or may be excluded.

Why it matters

Potential benefit: If successful, adding tea extract to a protein supplement could reduce strength loss and pain and speed recovery after muscle-damaging exercise.

How similar studies have performed: Protein supplementation is known to aid muscle recovery and some studies suggest polyphenol-rich extracts can help, but combining protein with tea extract specifically is less well established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Signed written informed consent
* Aged between 18-40 years
* Healthy subjects

Exclusion Criteria:

* Any type of food allergy (e.g. nuts)
* Health-related problems according to the "Physical Activity Readiness Questionnaire (PAR-Q)
* Current injury of the lower extremities
* Serious clinical back pain or current back injuries
* Orthopedic disorders
* Cardiovascular diseases
* Current Intake of blood-thinning medication
* Current Intake of anti-inflammatory medication

Where this trial is running

Fribourg, Canton of Fribourg

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.

View on ClinicalTrials.gov →

Conditions: Muscle Recovery, Protein, muscle recovery, Tea extract, EIMD

Last reviewed 2026-05-15 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.