Muscle RecoveryITMVC-DJNCT07113405
Influence of Tea Extract on Maximal Voluntary Knee Contraction Following Downhill Jogging
A study testing Protein and tea extract and Protein in people with Muscle Recovery, run by University of Fribourg at 1 site in Switzerland.
Trial summary
In this research project, we want to investigate whether the combined intake of proteins and tea extract has an influence on muscle regeneration compared to the sole intake of proteins or a placebo product. In the study, you will be randomly assigned to one of 3 groups. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Muscle Recovery
- What is being tested?
- Protein and tea extract and Protein
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteSwitzerland
- Study dates
- 1 Dec 2025to 30 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Signed written informed consent
- Aged between 18-40 years
- Healthy subjects
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site, 1 recruiting
- Recruiting
University of Fribourg
Fribourg, Canton of Fribourg, 1700
Sven Egger, Dr., +41 26 300 72 85, sven.egger@unifr.ch
About this study
Official title: The Influence of Tea Extract on Maximal Voluntary Knee Contraction After 30 Minutes of Downhill Jogging: a Randomized, Double-blind, Placebo-controlled Study
In this research project, we want to investigate whether the combined intake of proteins and tea extract has an influence on muscle regeneration compared to the sole intake of proteins or a placebo product. In the study, you will be randomly assigned to one of 3 groups. Neither the research group nor you will know which group you are assigned to. The study lasts 5 days for you as a participant. During these 5 days you will have to attend a total of 5 appointments in our laboratory. The groups differ only in the intake of the regeneration product, otherwise all measurements and appointments are identical. You will jog downhill for 30 minutes on the first day in order to strain your muscles. In order to be able to draw conclusions about the regeneration of your muscles, we will carry out the following measurements on all 5 days: Blood sampling at the fingertip, ultrasound of the thigh muscle, pain tolerance of the thigh muscle, strength tests of the thigh muscle, muscle function of the thigh muscle and jumping performance.
- Conditions
- Muscle Recovery
- Being tested
- Protein and tea extract, Protein, Placebo
- Keywords
- Protein, muscle recovery, Tea extract, EIMD
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Protein and tea extractDietary supplement
Participants in this group will receive 4 times a recovery drink containing protein and tea extract.
ProteinDietary supplement
Participants of this group will receive ten times a recovery drink containing only protein without tea extract.
PlaceboDietary supplement
Participants of this group will receive 10 times a placebo containing no protein nor tea extract.
| Study group | Role | What they receive |
|---|---|---|
| Protein and tea extract | Experimental | This group will receive a recovery drink containing protein and tea extract. Receives: Dietary Supplement: Protein and tea extract |
| Protein | Active comparator | This group will receive a recovery drink containing protein without tea extract. Receives: Dietary Supplement: Protein |
| Placebo | Placebo comparator | This group will receive a recovery drink containing a placebo product. The placebo product is a non-isoenergetic, non-protein, artificially flavoured liquid. Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in maximum knee extension force immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
The maximal force is measured in Nm while the participant is seated on an isokinetic device.
Measured: 5 days
Change in jump performance immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
The jump performance is measured in cm while the participant are performing counter movement jumps.
Measured: 5 days
Change in perceived pain immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Perceived pain is measured in Pa while the participant is seated on the isokinetic device. The measurement point is on vastus medialis muscle.
Measured: 5 days
Change in muscle thickness immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Muscle thickness is measured with b-mode ultrasound in mm while the participant is sitting on the isokinetic device. The measurement point is on the vastus medialis muscle.
Measured: 5 days
Change in creatine kinase levels immediately after exercise-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Creatine kinase is measured in U/L and determined using a capillary finger blood sample of 0.25 ml.
Measured: 5 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Aug 2025
- Study start1 Dec 2025
- Primary completion30 Dec 2026 (estimated)
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Muscle RecoveryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- randomized, double-blinded, placebo-controlled.
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Fribourg
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07113405
- Sponsor's protocol ID
- 2025-01302
- Other IDs
- 2025
- Acronym
- ITMVC-DJ
- Status last verified
- May 2026
- First submitted
- 25 Jul 2025
- Last updated
- 4 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: It is planned that only our research group will analyze and publish the data. Therefore, the data will not be passed on to other researchers.
Publications
Volpe-Fix AR, de Franca E, Silvestre JC, Thomatieli-Santos RV. The Use of Some Polyphenols in the Modulation of Muscle Damage and Inflammation Induced by Physical Exercise: A Review. Foods. 2023 Feb 21;12(5):916. doi: 10.3390/foods12050916.
PubMed 36900433Isaacs AW, Macaluso F, Smith C, Myburgh KH. C-Reactive Protein Is Elevated Only in High Creatine Kinase Responders to Muscle Damaging Exercise. Front Physiol. 2019 Feb 11;10:86. doi: 10.3389/fphys.2019.00086. eCollection 2019.
PubMed 30804809Hug F, Avrillon S, Del Vecchio A, Casolo A, Ibanez J, Nuccio S, Rossato J, Holobar A, Farina D. Analysis of motor unit spike trains estimated from high-density surface electromyography is highly reliable across operators. J Electromyogr Kinesiol. 2021 Jun;58:102548. doi: 10.1016/j.jelekin.2021.102548. Epub 2021 Mar 30.
PubMed 33838590Fischer AA. Pressure algometry over normal muscles. Standard values, validity and reproducibility of pressure threshold. Pain. 1987 Jul;30(1):115-126. doi: 10.1016/0304-3959(87)90089-3.
PubMed 3614975Del Vecchio A, Casolo A, Negro F, Scorcelletti M, Bazzucchi I, Enoka R, Felici F, Farina D. The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding. J Physiol. 2019 Apr;597(7):1873-1887. doi: 10.1113/JP277250. Epub 2019 Feb 6.
PubMed 30727028Coratella G, Varesco G, Rozand V, Cuinet B, Sansoni V, Lombardi G, Vernillo G, Mourot L. Downhill running increases markers of muscle damage and impairs the maximal voluntary force production as well as the late phase of the rate of voluntary force development. Eur J Appl Physiol. 2024 Jun;124(6):1875-1883. doi: 10.1007/s00421-023-05412-z. Epub 2024 Jan 10.
PubMed 38195943Botter A, Vieira TM, Loram ID, Merletti R, Hodson-Tole EF. A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles. J Appl Physiol (1985). 2013 Oct 15;115(8):1203-14. doi: 10.1152/japplphysiol.00090.2013. Epub 2013 Aug 1.
PubMed 23908313
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of Tea Extract on Maximal Voluntary Knee Contraction After 30 Minutes of Downhill Jogging: a Randomized, Double-blind, Placebo-controlled Study
- ClinicalTrials.gov ID
- NCT07113405
- Acronym / sponsor ID
- ITMVC-DJ / 2025-01302
- Conditions
- Muscle Recovery
- Keywords
- Protein, muscle recovery, Tea extract, EIMD
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- University of FribourgUniversity, hospital or other
- Study start
- 1 Dec 2025 (actual)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 8 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In this research project, we want to investigate whether the combined intake of proteins and tea extract has an influence on muscle regeneration compared to the sole intake of proteins or a placebo product. In the study, you will be randomly assigned to one of 3 groups. Neither the research group nor you will know which group you are assigned to. The study lasts 5 days for you as a participant. During these 5 days you will have to attend a total of 5 appointments in our laboratory. The groups differ only in the intake of the regeneration product, otherwise all measurements and appointments are identical. You will jog downhill for 30 minutes on the first day in order to strain your muscles. In order to be able to draw conclusions about the regeneration of your muscles, we will carry out the following measurements on all 5 days: Blood sampling at the fingertip, ultrasound of the thigh muscle, pain tolerance of the thigh muscle, strength tests of the thigh muscle, muscle function of the thigh muscle and jumping performance.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
- Model description
- randomized, double-blinded, placebo-controlled.
| Arm | Type | Receives |
|---|---|---|
| Protein and tea extract | Experimental | Dietary Supplement: Protein and tea extractThis group will receive a recovery drink containing protein and tea extract. |
| Protein | Active comparator | Dietary Supplement: ProteinThis group will receive a recovery drink containing protein without tea extract. |
| Placebo | Placebo comparator | Dietary Supplement: PlaceboThis group will receive a recovery drink containing a placebo product. The placebo product is a non-isoenergetic, non-protein, artificially flavoured liquid. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Signed written informed consent
- Aged between 18-40 years
- Healthy subjects
Key exclusion criteria (8 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Protein and tea extractParticipants in this group will receive 4 times a recovery drink containing protein and tea extract. | Dietary supplement | Protein and tea extract |
| ProteinParticipants of this group will receive ten times a recovery drink containing only protein without tea extract. | Dietary supplement | Protein |
| PlaceboParticipants of this group will receive 10 times a placebo containing no protein nor tea extract. | Dietary supplement | Placebo |
Primary outcome
Change in maximum knee extension force immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Time frame: 5 days
The maximal force is measured in Nm while the participant is seated on an isokinetic device.
Change in jump performance immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Time frame: 5 days
The jump performance is measured in cm while the participant are performing counter movement jumps.
Change in perceived pain immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Time frame: 5 days
Perceived pain is measured in Pa while the participant is seated on the isokinetic device. The measurement point is on vastus medialis muscle.
Change in muscle thickness immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Time frame: 5 days
Muscle thickness is measured with b-mode ultrasound in mm while the participant is sitting on the isokinetic device. The measurement point is on the vastus medialis muscle.
Change in creatine kinase levels immediately after exercise-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline.
Time frame: 5 days
Creatine kinase is measured in U/L and determined using a capillary finger blood sample of 0.25 ml.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
- Results publication: PubMed 36900433Volpe-Fix AR, de Franca E, Silvestre JC, Thomatieli-Santos RV. The Use of Some Polyphenols in the Modulation of Muscle Damage and Inflammation Induced by Physical Exercise: A Review. Foods. 2023 Feb 21;12(5):916. doi: 10.3390/foods12050916.
- Results publication: PubMed 30804809Isaacs AW, Macaluso F, Smith C, Myburgh KH. C-Reactive Protein Is Elevated Only in High Creatine Kinase Responders to Muscle Damaging Exercise. Front Physiol. 2019 Feb 11;10:86. doi: 10.3389/fphys.2019.00086. eCollection 2019.
- Results publication: PubMed 33838590Hug F, Avrillon S, Del Vecchio A, Casolo A, Ibanez J, Nuccio S, Rossato J, Holobar A, Farina D. Analysis of motor unit spike trains estimated from high-density surface electromyography is highly reliable across operators. J Electromyogr Kinesiol. 2021 Jun;58:102548. doi: 10.1016/j.jelekin.2021.102548. Epub 2021 Mar 30.
- Results publication: PubMed 3614975Fischer AA. Pressure algometry over normal muscles. Standard values, validity and reproducibility of pressure threshold. Pain. 1987 Jul;30(1):115-126. doi: 10.1016/0304-3959(87)90089-3.
- Results publication: PubMed 30727028Del Vecchio A, Casolo A, Negro F, Scorcelletti M, Bazzucchi I, Enoka R, Felici F, Farina D. The increase in muscle force after 4 weeks of strength training is mediated by adaptations in motor unit recruitment and rate coding. J Physiol. 2019 Apr;597(7):1873-1887. doi: 10.1113/JP277250. Epub 2019 Feb 6.
- Results publication: PubMed 38195943Coratella G, Varesco G, Rozand V, Cuinet B, Sansoni V, Lombardi G, Vernillo G, Mourot L. Downhill running increases markers of muscle damage and impairs the maximal voluntary force production as well as the late phase of the rate of voluntary force development. Eur J Appl Physiol. 2024 Jun;124(6):1875-1883. doi: 10.1007/s00421-023-05412-z. Epub 2024 Jan 10.
- Results publication: PubMed 23908313Botter A, Vieira TM, Loram ID, Merletti R, Hodson-Tole EF. A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles. J Appl Physiol (1985). 2013 Oct 15;115(8):1203-14. doi: 10.1152/japplphysiol.00090.2013. Epub 2013 Aug 1.
- Individual participant dataSharing planned: No. It is planned that only our research group will analyze and publish the data. Therefore, the data will not be passed on to other researchers.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Protein and tea extract and Protein in people with Muscle Recovery, run by University of Fribourg at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sven Egger, Dr. (+41 26 300 72 85, sven.egger@unifr.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in maximum knee extension force immediately after training-induced muscle damage and 24, 48, 72, and 96 hours thereafter compared to baseline. (time frame: 5 days). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07113405, which also lists 7 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 May 2026.