<![CDATA[Speed ??training is a crucial component in improving performance in martial arts, particularly karate, which relies heavily on punching and kicking speed in competitions. This study aims to analyze the effect of speed training on improving punching and kicking performance in adolescent karate athletes aged 15–17 years and to interpret its biomechanical implications for developing evidence-based training designs. This study employed a cross-sectional analytical design with a determinant-based biomechanical approach involving kumite karate athletes using three-dimensional motion capture and force plates for kinematic and kinematic analysis. The results showed that speed training significantly increased athletes' punching and kicking speeds, with the primary biomechanical variables being hip angular velocity, trunk rotation, ground reaction force, and momentum as the primary determinants of performance. These findings underscore the importance of integrating a biomechanical approach into evidence-based speed training designs to effectively and measurably improve adolescent karate performance. Practical implications of this study suggest that coaches can optimize training programs by emphasizing kinetic chain coordination, distal segment acceleration, and increasing neuromuscular capacity during the adolescent developmental phase. Furthermore, the results of this study provide an empirical basis for developing a more specific, systematic, and appropriate speed training model tailored to the performance needs of modern competitive karate. Further research is recommended in a broader population in the future.]]>
