This study will investigate the effects of flywheel exercises targeting the upper extremities on athletic performance, muscle oxygenation, physical fatigue, and muscle strength in adolescent basketball players. A total of 36 healthy male adolescent basketball players aged 10-18 years will be included in the study and divided into two groups using stratified randomization: a flywheel exercise group (n=18) and a traditional strength training group (n=18).

Athletic skills will be assessed using the Johnson Basketball Skill Tests (passing test, dribbling test, shooting test), the Basketball Shooting Accuracy Test, and the Functional Shooting Performance Index (FAPI). Upper extremity muscle oxygenation will be measured using near-infrared spectroscopy (NIRS) with a Moxy muscle oxygen meter. Physical fatigue level will be determined using the Modified Borg Scale. Upper extremity muscle strength will be assessed using a Kinvent hand dynamometer and the Seated Single Arm Ball Throw Test. The flywheel group will undergo eccentric weight flywheel exercises three times a week for eight weeks. The traditional strength training group will follow a strength training program using dumbbells for the same duration and frequency. All assessments will be conducted before and after the training program.

Adolescence is a critical period in which athletic performance and musculoskeletal adaptations develop rapidly. In sports that actively utilize the upper extremities, such as basketball, strength, coordination, and fatigue tolerance directly affect performance. In recent years, flywheel exercise systems, which allow for eccentric loading, have emerged as an effective training method for improving muscle strength and neuromuscular adaptations. However, scientific evidence regarding the effects of these systems on adolescent athletes is limited. This study was planned to investigate the effects of flywheel exercises targeting the upper extremities on athletic performance, muscle oxygenation, and physical fatigue in adolescent basketball players. The study will be conducted using a randomized controlled design, with participants divided into two groups: a flywheel exercise group and a traditional strength training group. Both groups will receive a structured upper extremity strength training program of equal duration and frequency. Throughout the study, all participants will continue their routine basketball training; only the strength training method applied will differ between the groups. Assessments will be conducted before and after the training program, and intra-group and between-group changes will be analyzed. The findings are expected to provide important information about the applicability of flywheel exercises in adolescent athletes and their potential effects on performance.

Inclusion Criteria:

• Volunteer male basketball players aged 10-18 who have played basketball for at least one year,
• Who have regularly attended training sessions for the past 6 months,
• Who do not have an injury that would restrict their participation in training will be included in the study.

Exclusion Criteria:

• Those who have undergone upper extremity surgery within the last year
• Those with neurological, cardiovascular, respiratory, or metabolic diseases (e.g., epilepsy, heart disease, asthma, diabetes, etc.)
• Those who have sustained any upper extremity musculoskeletal injury within the last year

Individual participant data (IPD) will not be shared due to the small sample size, the involvement of adolescent participants, and data protection and confidentiality considerations. Data will be used only for the purposes defined in the study protocol.