Isokinetic Knee Strength, Bilateral Muscle Balance, and Anaerobic Performance in Adolescent Athletes (ISOK-WAnT)

November 2, 2026 updated by: Assoc. Prof. Dr. Özgür EKEN, Inonu University

Relationship of Isokinetic Knee Strength and Bilateral Muscle Balance With Anaerobic Performance in Adolescent Athletes

This study looks at how strong the knee muscles are in adolescent athletes and how this strength relates to short-term, high-intensity (anaerobic) performance. Strong, well-balanced thigh muscles may help athletes produce more power during sport movements, but this has not been studied well in teenagers. Male athletes aged 15-16 years will be measured on two separate days. On the first day, their height and body weight will be measured and the strength of the muscles at the front (quadriceps) and back (hamstrings) of both thighs will be tested on a special strength-testing machine. On the second day, they will do a 30-second all-out cycling test to measure anaerobic power. The study will compare the right and left legs and will examine whether knee muscle strength and the balance between the front and back thigh muscles are linked to power output during the cycling test. No treatment or intervention will be given. The results may help coaches and sports scientists understand the physical development of adolescent athletes.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Lower-limb strength and anaerobic power are important parts of the physical profile of adolescent athletes in high-intensity sports such as wrestling. Isokinetic dynamometry allows knee extensor (quadriceps) and flexor (hamstring) strength and the balance between these muscle groups to be measured objectively, while the 30-second Wingate Anaerobic Test (WAnT) is a widely used laboratory test of anaerobic performance. Evidence on how these measures relate to each other in adolescent athletes is limited.

This is a cross-sectional, correlational observational study. Twenty-one male adolescent athletes aged 15-16 years will be recruited in Malatya, Turkey. Written informed consent will be obtained from parents or legal guardians, and assent from participants. Testing will take place on two separate days to limit fatigue. Participants will avoid heavy exercise for 48 hours and caffeine for 12 hours before testing.

Day 1: Height and body mass are measured and body mass index is calculated. Concentric knee extension and flexion are then tested bilaterally on a HUMAC NORM isokinetic dynamometer at 60, 120 and 180 degrees per second (three practice repetitions followed by five maximal repetitions at each speed; 45 seconds of rest between speeds and 10 minutes between limbs). Peak torque is recorded for the quadriceps and hamstrings of each limb, and the conventional hamstring-to-quadriceps (H/Q) ratio is calculated.

Day 2: Participants complete a 30-second WAnT on a mechanically braked cycle ergometer (Monark 874E) with a braking load of 0.075 kg per kg of body mass, after a standardized warm-up. Peak power, mean power and fatigue index are recorded.

Differences between the right and left limbs will be examined with paired-samples t-tests (with 95% confidence intervals and Cohen's dz). Associations between isokinetic variables and WAnT outcomes will be examined with Pearson correlation. The sample size (minimum 19) was calculated with G*Power for a correlation of r = 0.60 (alpha = 0.05, power = 0.80); 21 participants are planned to allow for possible data loss.

Study Type

Observational

Enrollment (Estimated)

21

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

Study Contact Backup

Study Locations

  • Turkey (Türkiye)
    • Malatya
      • Malatya, Malatya, Turkey (Türkiye), 44280
        • Department of Physical Education and Sport Teaching, Faculty of Sports Sciences, Inonu University,
        • Contact:
        • Contact:
        • Principal Investigator:
          • Özgür Eken, PhD, Assoc. Prof
        • Sub-Investigator:
          • Denizhan Caliskan, Dr.

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

15 years to 16 years (Child)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Sampling Method

Non-Probability Sample

Study Population

Male adolescent athletes aged 15-16 years who actively wrestle and train regularly in Malatya, Turkey. Participants are healthy athletes recruited from local clubs on a voluntary basis.

Description

Inclusion Criteria:

  • Actively practicing wrestling in Malatya, Turkey
  • Male, aged 15-16 years
  • At least 2 years of regular training (at least 2 days per week)
  • No lower-extremity injury or surgery in the last 6 months
  • No musculoskeletal, cardiometabolic, or neurological condition that could prevent testing
  • Willing to participate in all planned tests
  • Written informed consent signed by parent or legal guardian, and assent from the participant

Exclusion Criteria: * Younger than 15 or older than 16 years

  • Lower-extremity injury or surgery within the last 6 months
  • Musculoskeletal, cardiometabolic, or neurological condition that could prevent testing
  • Open wound, varicose veins, acute inflammation, or history of thrombosis
  • Regular use of analgesic or anti-inflammatory medication or ergogenic supplements in the last 3 months
  • Unable to attend all planned testing sessions
  • Unwilling to follow the pre-test rules (no heavy exercise for 48 hours, no caffeine for 12 hours, usual training and diet)
  • Withdrawal during the study due to non-compliance, incomplete sessions, serious injury or illness, or participant request

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

  • Observational Models: COHORT
  • Time Perspectives: CROSS_SECTIONAL

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Adolescent Athletes

Male adolescent athletes aged 15-16 years who regularly train and compete. All participants complete anthropometric measurements, bilateral isokinetic knee strength testing, and the Wingate Anaerobic Test on separate days.
Diagnostic test: Isokinetic Knee Strength Testing

Bilateral concentric knee extension and flexion tested on an isokinetic dynamometer at 60, 120, and 180 degrees per second. Peak torque and the conventional hamstring-to-quadriceps ratio are recorded.

Diagnostic test: Wingate Anaerobic Test

A 30-second all-out cycling test on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass. Peak power, mean power, and fatigue index are recorded.

Other Names:
  • WAnT

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Isokinetic Peak Torque of the Knee Extensors and Flexors
Time Frame: Day 1 of testing (single measurement session)

Peak torque (N·m) of the quadriceps and hamstrings, measured separately for the right and left limbs at 60, 120, and 180 degrees per second on an isokinetic dynamometer (highest value across five maximal concentric repetitions). Right-to-left differences and associations with Wingate Anaerobic Test outcomes are analyzed.
Day 1 of testing (single measurement session)
Wingate Anaerobic Test Peak Power
Time Frame: Day 2 of testing (single measurement session)

Highest power output (W) achieved during the 30-second Wingate Anaerobic Test performed on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass.
Day 2 of testing (single measurement session)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Conventional Hamstring-to-Quadriceps (H/Q) Strength Ratio
Time Frame: Day 1 of testing

Concentric hamstring peak torque divided by quadriceps peak torque, multiplied by 100 (%), calculated for each limb at 60, 120, and 180 degrees per second.
Day 1 of testing
Wingate Anaerobic Test Mean Power
Time Frame: Day 2 of testing

Average power output (W) maintained across the 30-second Wingate Anaerobic Test.
Day 2 of testing
Wingate Anaerobic Test Fatigue Index
Time Frame: Day 2 of testing

Percentage decline from peak power to the lowest power output during the test: [(peak power - minimum power) / peak power] × 100.
Day 2 of testing

Collaborators and Investigators

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

Sponsor

Inonu University

Investigators

  • Principal Investigator: Özgür Eken, PhD, Assoc. Prof., Inonu University, Faculty of Sport Sciences
  • Study Director: Denizhan Çalışkan, Dr., Eskisehir Provincial Directorate of Youth and Sports, Eskisehir, Türkiye

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

  • Aagaard, P., Simonsen, E. B., Magnusson, S. P., Larsson, B., & Dyhre-Poulsen, P. (1998). A new concept for isokinetic hamstring:quadriceps muscle strength ratio. The American Journal of Sports Medicine, 26(2), 231-237. Alemdaroğlu, U. (2012). The relationship between muscle strength, anaerobic performance, agility, sprint ability and vertical jump performance in professional basketball players. Journal of Human Kinetics, 31, 149-158. Chaabene, H., Negra, Y., Bouguezzi, R., Capranica, L., Franchini, E., Prieske, O., Hbacha, H., & Granacher, U. (2017). Physical and physiological attributes of wrestlers: An update. Journal of Strength and Conditioning Research, 31(5), 1411-1442. Iossifidou, A., Baltzopoulos, V., & Giakas, G. (2005). Isokinetic knee extension and vertical jumping: Are they related? Journal of Sports Sciences, 23(9), 1121-1127.

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)

December 28, 2026

Primary Completion (Estimated)

January 28, 2027

Study Completion (Estimated)

January 28, 2027

Study Registration Dates

First Submitted

November 2, 2026

First Submitted That Met QC Criteria

November 2, 2026

First Posted (Actual)

November 6, 2026

Study Record Updates

Last Update Posted (Actual)

November 6, 2026

Last Update Submitted That Met QC Criteria

November 2, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • INONU-ISOKINETIC-2026-01
  • IKINETIK-WAnT-2026 (Other Identifier: Inonu University)

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 participants are minors and the consent forms state that data will be used only for the purposes of this research and kept confidential. Aggregate results will be published.

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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