This cross-sectional study aims to investigate the association between core endurance, medicine ball throw performance, and static balance in young male judokas aged 10-13 years. Core endurance will be assessed using McGill's isometric core endurance protocol, including trunk flexion, trunk extension, and lateral bridge tests. Explosive performance will be evaluated using the backward overhead medicine ball throw test, while static balance will be assessed using the Flamingo Balance Test. Correlation and regression analyses will be conducted to examine the relationships between core endurance and performance variables. The findings may contribute to understanding the role of core endurance in youth judo performance.

Judo is a high-intensity combat sport that requires explosive power, postural control, balance, and efficient force transmission throughout the kinetic chain. Core musculature plays a central role in stabilizing the trunk and transferring force between the lower and upper extremities during sport-specific movements. In judo, throwing techniques such as ippon-seoi-nage, uchi-mata, and harai-goshi require substantial trunk stabilization and rotational force production.

Although previous studies have investigated the importance of core training and trunk muscle function in athletic performance, limited evidence exists regarding the association between core endurance and sport-related performance parameters in young judokas. Understanding these relationships may provide valuable insights for training program design in youth judo athletes.

Therefore, the purpose of this cross-sectional observational study is to examine the association between core endurance, medicine ball throw performance, and static balance in male judokas aged 10-13 years.

Twenty male judokas with at least two years of regular judo training experience will participate in the study. Core endurance will be evaluated using McGill's isometric core endurance test battery, including trunk flexion, trunk extension, right lateral bridge, and left lateral bridge tests. Explosive upper-body performance will be assessed using the backward overhead medicine ball throw test with a 2-kg medicine ball. Static balance performance will be evaluated using the Flamingo Balance Test.

Data collection will be conducted over two testing sessions separated by at least 48 hours. Spearman rank correlation analyses and regression analyses will be used to examine the relationships between variables.

The study hypothesizes that greater core endurance will be positively associated with medicine ball throw performance and static balance performance in young male judokas.

Inclusion Criteria:

• Being a male judoka aged between 10 and 13 years.
• Having at least 2 years of regular judo training experience
• Training at least 3 days per week regularly
• Volunteering to participate in the study and providing parental informed consent
• Being free from any physical injuries or health conditions that could interfere with physical performance testing

Exclusion Criteria:

• Having any acute or chronic musculoskeletal injuries within the last 6 months
• Having a history of surgery that affects physical movement or balance
• Using any medication or supplements that could influence physical performance or balance during the testing period
• Failure to complete all the required test protocols
• Any neurological or vestibular disorders that affect static balance

The individual participant data will not be shared to maintain the confidentiality of the participants, as per the ethical approval guidelines