An interventional study of High-Frequency Functional Training Group (HFFT) and Low-Frequency Functional Training Group (LFFT) in Exercise Therapy, sponsored by Biruni University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 12 Years to 18 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-28.
Sponsored by Biruni University · Not applicable, Interventional, and Treatment
Adolescence is a period characterized by rapid growth and development, characterized by intense structural, functional, and neuromuscular changes in the musculoskeletal system. The rapid height growth and proportional changes that occur during this period can negatively impact athletic performance by disrupting muscle strength and flexibility. Deficiencies in lower extremity muscle strength, in particular, can lead to decreased performance and increased injury risk in sports requiring high agility, balance, and explosive power, such as tennis.
Functional training programs are holistic exercise approaches that aim to improve neuromuscular control, balance, coordination, and muscle strength by simultaneously training multiple muscle groups. This type of training is particularly important in adolescent athletes because it supports the development of strength, endurance, and explosive power. Training frequency, in turn, plays a decisive role in muscle adaptation and performance enhancement by influencing the balance between loading and recovery.
Literature contains limited studies directly examining the effects of functional training frequency on explosive power performance in young athletes. Most existing research has focused on adult or professional athletes, and experimental studies comparing the effects of different training frequencies in adolescent tennis players are insufficient.
In this context, the aim of our study was to examine the effects of a six-week functional training program implemented at different training frequencies on lower extremity explosive strength parameters in adolescent tennis athletes.
Adolescence is a dynamic period accompanied by rapid growth and development, characterized by intense structural, functional, and neuromuscular changes in the musculoskeletal system. During this period, weakness in the lower extremity muscles can lead to decreased performance and increased injury risk in sports requiring agility, balance, and explosive power, such as tennis.
Functional training programs are comprehensive exercise approaches that improve neuromuscular coordination, balance, and stabilization by simultaneously activating multiple muscle groups. These types of training are particularly important for young athletes because they support sport-specific movement patterns, increase muscle strength, and optimize the energy transfer chain. Training frequency is a key variable in determining muscle adaptation, recovery time, and load balance. Therefore, studies examining the effects of different training frequencies on explosive power development in young tennis athletes are of great scientific and practical value.
Healthy adolescent tennis players who volunteer to participate will be included in the study. After recording demographic and sport-specific information, participants' explosive strength performance will be assessed using the Countermovement Jump (CMJ), Squat Jump (SJ), Single Leg Jump (SLJ), and Reactive Strength Index (RSI) tests. Participants will be randomly assigned to two groups: the first group will participate in a 60-minute functional training program once a week, and the second group will participate in a 60-minute functional training program three times a week. The programs will last six weeks, and all sessions will be conducted by the same physiotherapist. Assessments will be conducted before and after the six-week training program. The study employed a two-group, pretest-posttest design. This study aims to demonstrate the effects of different training frequencies on explosive strength development in adolescent tennis athletes, contributing to the scientific basis of training plans for young athletes and to optimize performance.
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Exclusion Criteria:
Participants in this group performed the functional training program once per week for six consecutive weeks. Each session lasted approximately 60 minutes and included dynamic warm-up, multi-joint functional exercises, and cool-down activities supervised by the same physiotherapist.
Other: Low-Frequency Functional Training Group (LFFT)
Participants in this group performed the same functional training program three times per week for six consecutive weeks. Each 60-minute session followed the same structure as the low-frequency program and was conducted under identical supervision and environmental conditions.
Other: High-Frequency Functional Training Group (HFFT)
Participants in this group performed the same functional training program three times per week for six consecutive weeks. Each 60-minute session followed the same structure as the low-frequency program and was conducted under identical supervision and environmental conditions.
Also known as: exercise
Participants in this group performed the same functional training program once per week for six consecutive weeks. Each 60-minute session followed the same structure as the low-frequency program and was conducted under identical supervision and environmental conditions.
Also known as: exercise
Countermovement Jump Test (CMJ)
The participant performs a rapid squat from an upright position with hands on hips, followed by a maximum vertical jump. This assesses lower extremity explosive strength and elastic energy utilization.
Time frame: 6 weeks
Squat Jump (SJ) Test
The participant is fixed in a position of approximately 90° flexion of the knee and hip joints, then performs a maximum vertical jump without using the arms. It measures pure concentric muscle strength.
Time frame: 6 weeks
Reactive Strength Index (RSI) Test
It's typically performed using a drop jump protocol. The participant jumps onto the platform from a specific height and bounces back up as quickly as possible after contact with the ground. RSI is calculated based on jump height and ground contact time; it measures reactive strength and stretch-shortening cycle (SSC) effectiveness.
Time frame: 6 weeks
Standing Long Jump (SLJ) Test
The participant stands with their feet parallel and jumps as far forward as possible using their arms. Lower extremity explosive strength is assessed by measuring the jump distance.
Time frame: 6 weeks
Assessment of normal joint motion
The Normal Joint Motion Assessment (NJM) Test is an objective method used to measure joint range of motion. In the study, participants' hip and knee joint flexion and extension angles will be assessed using the NJM test using a universal goniometer. Measurements will be made using active range of motion, and each measurement will be repeated three times and averaged.
Time frame: 6 weeks
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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