Influence of Tea Extract on Maximal Voluntary Knee Contraction Following Downhill Jogging

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

Overview

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.

Interventions

• Dietary supplement Protein and tea extract
  Participants in this group will receive 4 times a recovery drink containing protein and tea extract.
• Dietary supplement Protein
  Participants of this group will receive ten times a recovery drink containing only protein without tea extract.
• Dietary supplement Placebo
  Participants of this group will receive 10 times a placebo containing no protein nor tea extract.

Primary outcome measures

• 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]
• 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]
• 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]
• 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]
• 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]

Eligibility 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Basic science

Study locations

Switzerland · 1 center

• University of Fribourg — Fribourg

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. PMID 36900433
• Isaacs 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. PMID 30804809
• Hug 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. PMID 33838590
• Fischer 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. PMID 3614975
• Del 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. PMID 30727028
• Coratella 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. PMID 38195943
• Botter 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. PMID 23908313

Identifiers

NCT: NCT07113405 · 2025-01302

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗