Comparison of the effects of eight weeks of neuromuscular, plyometric, and combined training on soccer performance and skills in adolescent male players with different levels of biological maturation and motor competence

Comparing the effects of eight weeks of neuromuscular, plyometric, and combined training on physical performance indicators (strength, speed, agility, explosive power, and endurance) and football technical skills (passing accuracy, shooting accuracy, dribbling, ball control, and decision-making) in adolescent male players aged 13‑16 years with different levels of biological maturation and motor competence.

Randomized controlled trial, single‑blind (outcome assessors), parallel four‑group, pre‑test/post‑test, sample size 60, software randomization, phase not applicable.

Study setting: Football academy. After screening and consent, 8‑week intervention will be held in standard hall under expert trainer supervision. Blinding: Assessments by blinded assessors at pre‑test and post‑test.

Inclusion criteria: male adolescents 13‑16 years; at least 2 years of football training; medical clearance; no injury in last 3 months; consent. Exclusion criteria: grade 2 or higher injury in last 6 months; uncontrolled chronic disease; use of steroids or growth hormones; concurrent participation in another training program.

Intervention group 1 (Neuromuscular) : 8 weeks, 3×45‑60min/week, balance, core stability, and motor control exercises. Intervention group 2 (Plyometric): 8 weeks, 3×45‑60min/week, jumping and explosive exercises. Intervention group 3 (Combined): 8 weeks, 3×45‑60min/week, combination of neuromuscular and plyometric training. Control group: no intervention.

Physical performance (lower body strength by vertical jump; speed by 20m sprint; agility by T‑test; upper body strength by bench press; aerobic endurance by Yo‑Yo test; anaerobic power by RAST); football technical skills (passing accuracy, shooting accuracy, dribbling, ball control, and decision‑making).

After initial screening and confirmation of eligibility, the names of all eligible participants are recorded alphabetically in a preliminary list. Using the free online software Randomization.com (available at: www.randomization.com), a simple randomization sequence is generated with individual as the unit of randomization. The total number of participants (60) is entered into the software and the "Simple Randomization" option is selected. The software assigns each participant equally and randomly to one of four study groups (Neuromuscular, Plyometric, Combined, and Control) using a random number-based algorithm. Since no stratification is used, all participants have an equal chance of being assigned to any of the four groups. The randomization sequence is printed as a table and placed into sealed, opaque, and numbered envelopes to ensure full allocation concealment. Each envelope is numbered externally and is opened only after completion of pre-test assessments by an independent person (not involved in the research process), in the order of the envelope numbers, and the participant is allocated to the corresponding group. This process is repeated for all 60 participants, with no possibility of interference or prediction in group allocation.

In this study, due to the nature of the exercise intervention, complete blinding is not possible. However, outcome assessors who are responsible for administering the performance and skill tests will be blinded to participants' group allocation. Participants, the principal investigator, and trainers are aware of the intervention type. Outcome assessors are blinded through participant coding and lack of access to group allocation information.

De-identified individual participant data, study protocol, statistical analysis plan, informed consent form, clinical study report, and data dictionary: All collected data related to outcome variables (physical performance indicators and football technical skills) will be shared completely without identifying information. Documentation regarding methodology, forms used, and analysis plan will also be provided.

Six months after publication of study results

Researchers affiliated with reputable academic and scientific institutions who have an approved research proposal by their institutional ethics committee.

Data may be used solely for research purposes and secondary analyses related to exercise physiology and sports performance. Commercial use of the data is not permitted. All users must adhere to ethical requirements and maintain data confidentiality, and must report any findings from their analyses to the primary authors. Requests must include a detailed description of the project and its objectives.

To request data, please contact the corresponding author, Mr. Alaa Al-shamilavi, via email at Al-shamilavi@modares.ac.ir. Requests may also be submitted through the Department of Exercise Sciences at Tarbiat Modares University.

Upon submission of a request via email, the corresponding author will review the application. After approval by the university ethics committee, the request will be forwarded to the research team. If finally approved, de-identified data will be provided within two to four weeks via email or a secure data-sharing platform.

Data will be provided solely for non-commercial purposes, with full adherence to ethical principles and confidentiality of participant information.