Indirect Biomarkers and Exercise Induced Muscle Damage

March 26, 2026 updated by: Vassilis Paschalis

Repeated Bout Effect and Indirect Biomarkers After Eccentric Exercise Induced Muscle Damage

The purpose of this study is to investigate the magnitude of changes in biomarkers of exercise-induced muscle damage following an acute bout of eccentric exercise of the knee extensors performed on an isokinetic dynamometer. Moreover, these biomarkers will be assessed at different time points after the initial intervention, checking the repeated bout effect phenomenon.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Volunteers will visit the laboratory a total of two times. During the first visit, in all participants will be assessed indirect markers of exercise-induced muscle damage (i.e., peak torque, delayed-onset muscle soreness, range of motion, rate of force development), blood parameters (i.e., creatine kinase and c-Reactive Protein), and muscle oxygenation using near infrared spectroscopy. Afterwards, participants will perform an eccentric exercise protocol for the knee extensors consisting of 5 sets of 15 maximal-intensity repetitions at an angular velocity of 60°/s. The second visit will be at different time points between participant, where the indirect mauls damage biomarkers will be reassessed before and after the same isokinetic eccentric exercise (i.e., 5 sets of 15 maximal-intensity repetitions at an angular velocity of 60°/s).

Study Type

Interventional

Enrollment (Actual)

48

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 Locations

  • Greece
    • Attica
      • Athens, Attica, Greece, 17237
        • Department of Physical Education and Sport Science, National and Kapodistrian University of Athens

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:

  • Healthy, physically active, males

Exclusion Criteria:

  • Musculoskeletal injuries, chronic diseases, smoking, consumption of any sports/antioxidant supplements or medication, and potential inflammatory conditions

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: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Initial bout of isokinetic eccentric exercise
Isokinetic eccentric exercise will be performed, while before and 48h after a number of indirect biomarkers will be assessed
Other: Eccentric Exercise
Eccentric exercise will be performed using an isokinetic dynamometer. It will be consisted of 5 set of 15 eccentric contraction of the knee extensors at an angular velocity of 60o/s. The intensity will be maximal voluntary.
Experimental: Subsequent bout of isokinetic eccentric exercise
Isokinetic eccentric exercise will be performed, while before and 48h after a number of indirect biomarkers will be assessed
Other: Eccentric Exercise
Eccentric exercise will be performed using an isokinetic dynamometer. It will be consisted of 5 set of 15 eccentric contraction of the knee extensors at an angular velocity of 60o/s. The intensity will be maximal voluntary.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Delayed onset muscle soreness
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
Pain will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.
Peak torque output
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
Peak torque will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.
Range of Motion
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
The free pain range of motion will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.
Muscle oxygenation
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
Using near infrared spectroscopy, the oxygenation of the knee extensors will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.
Creatine kinase
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
Creatine kinase will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.
Muscle thickness using ultrasound
Time Frame: Baseline and 48 hours after the eccentric exercise bout.
Participants's knee extensors muscle thickness will be assessed at baseline (before the eccentric exercise bout) and again at 48 hours (2 days) after the eccentric exercise bout.
Baseline and 48 hours after the eccentric exercise bout.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vassilis Paschalis

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

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 (Actual)

August 22, 2025

Primary Completion (Actual)

November 27, 2025

Study Completion (Estimated)

July 15, 2026

Study Registration Dates

First Submitted

February 11, 2026

First Submitted That Met QC Criteria

March 26, 2026

First Posted (Actual)

March 31, 2026

Study Record Updates

Last Update Posted (Actual)

March 31, 2026

Last Update Submitted That Met QC Criteria

March 26, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 1858/03-10-2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared because participant consent did not include public data sharing and the dataset size increases re-identification risk.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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