An observational study in Athletic Performance, sponsored by Yusufcan Keskin. Completed at 1 site in Turkey (Türkiye). Open to male participants aged 17 Years to 18 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by Yusufcan Keskin · Observational
This observational, cross-sectional study examines the relationships between body measurements and athletic performance in elite under-18 male soccer players. The study includes 125 male players aged 17-18 years from professional football club academies competing in the Turkish Football Federation Development League.
The main objective is to investigate whether height, body mass, and body mass index are associated with sprint speed, vertical jump performance, change-of-direction ability, and intermittent endurance. The study also examines the relationships between lower-limb muscle strength and selected athletic performance measures.
Participants undergo a single assessment session consisting of body measurements, countermovement jumps, 10-, 20-, and 30-meter sprint tests, the 505 change-of-direction test, isometric knee-flexor strength measurements, and the Yo-Yo Intermittent Recovery Test Level 1.
No training intervention or experimental treatment is administered. The study aims to improve understanding of the physical characteristics associated with athletic performance in elite youth soccer players.
This study uses a quantitative, observational, cross-sectional design to investigate associations between anthropometric characteristics and athletic performance in elite under-18 male soccer players.
The study population consists of 125 male soccer players aged 17-18 years who participate in professional football club academy programs and compete in the Turkish Football Federation Development League. Assessments are conducted at the Performance Laboratory of the Faculty of Sport Sciences, Istanbul Gedik University, Türkiye.
Data collection takes place over seven testing days, with approximately 20 participants assessed per day. Each participant completes the assessment battery during a single testing session.
Anthropometric measurements include standing height, body mass, and calculated body mass index. Following a standardized 15-minute dynamic warm-up, participants complete the physical performance assessments in a fixed sequence.
Countermovement jump height is assessed using VALD ForceDecks force plates. Linear sprint performance is evaluated over 10, 20, and 30 meters using the SmartSpeed electronic timing system. Change-of-direction performance is measured using the 505 test for both turning legs.
Isometric knee-flexor strength is measured using the VALD NordBord system under two testing conditions: ISO-30, corresponding to 30 degrees of knee flexion, and ISO-Prone, corresponding to a prone position with the knees extended at 0 degrees. Peak force is recorded separately for the dominant and nondominant limbs.
Intermittent endurance is evaluated using the Yo-Yo Intermittent Recovery Test Level 1, with total completed running distance recorded in meters.
The primary analyses examine associations between height, body mass, body mass index, and athletic performance outcomes. Secondary analyses examine relationships between countermovement jump height, body-mass-normalized knee-flexor force, and selected performance outcomes. Absolute knee-flexor force is also compared between testing conditions and between dominant and nondominant limbs.
The study does not involve randomization, experimental training interventions, or longitudinal follow-up. Statistical analyses are designed to identify associations rather than establish causal relationships.
Ethical approval was obtained from the Istanbul Gedik University Ethics Committee on April 29, 2024 (meeting number 2024/4, application reference 332421). Written informed consent or parental consent and participant assent were obtained as appropriate.
This is the only study on the registry with Yusufcan Keskin as lead sponsor.
Counted across the registry records on this site, refreshed daily.
The study population consisted of 125 elite under-18 male soccer players recruited from professional football club academies competing in the Turkish Football Federation Development League. Participants underwent anthropometric and physical performance assessments, including sprint, countermovement jump, change-of-direction, isometric knee-flexor strength, and intermittent endurance tests. The study employed an observational, cross-sectional design without experimental interventions.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Male soccer players aged 17-18 years.
Participation in an elite youth soccer academy or professional football club development program.
Active participation in regular soccer training and competition.
Willingness to participate in anthropometric and physical performance assessments.
Provision of written or parental consent and participant assent, as applicable.
Exclusion Criteria:
Current musculoskeletal injury preventing safe participation in physical performance testing.
Medical conditions that contraindicate maximal physical exertion.
Inability to complete the required assessment procedures.
Withdrawal of consent before or during data collection.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This cohort consisted of 125 elite under-18 male soccer players participating in professional football academy programs. Participants underwent a single assessment session involving anthropometric measurements, countermovement jump testing, linear sprint assessments, the 505 change-of-direction test, isometric knee-flexor strength testing, and the Yo-Yo Intermittent Recovery Test Level 1. No experimental training intervention or treatment was administered.
Other: Physical Performance Assessment Battery
Participants underwent a standardized physical performance assessment battery, including anthropometric measurements, countermovement jump testing, 10-, 20-, and 30-meter sprint tests, the 505 change-of-direction test, isometric knee-flexor strength assessments, and the Yo-Yo Intermittent Recovery Test Level 1. These procedures were performed exclusively for observational data collection. No experimental training intervention or therapeutic treatment was administered.
10-Meter Sprint Time
Time required to complete a 10-meter linear sprint, measured in seconds using the SmartSpeed electronic timing system. Lower values indicate better sprint performance.
Time frame: During a single assessment session (baseline)
20-Meter Sprint Time
Time to complete a 20-meter sprint, measured in seconds using electronic timing gates.
Time frame: During a single assessment session (baseline)
30-Meter Sprint Time
Time to complete a 30-meter sprint, measured in seconds using electronic timing gates.
Time frame: During a single assessment session (baseline)
Countermovement Jump Height
Vertical jump height measured in centimeters using VALD ForceDecks force plates.
Time frame: During a single assessment session (baseline)
505 Change-of-Direction Time
Time to complete the 505 change-of-direction test, measured in seconds for each turning leg.
Time frame: During a single assessment session (baseline)
Isometric Knee-Flexor Peak Force
Peak knee-flexor force measured using VALD NordBord at 0° and 30° knee-flexion positions, recorded for each limb.
Time frame: During a single assessment session (baseline)
Yo-Yo Intermittent Recovery Test Level 1 Distance
Total distance completed during the Yo-Yo IR1 test, measured in meters.
Time frame: During a single assessment session (baseline)
Anthropometric Characteristics
Standing height (cm), body mass (kg), and calculated body mass index (kg/m²).
Time frame: During a single assessment session (baseline)
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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