The present study investigates effect of lower body plyometric training on upper body performance, muscle size, hormonal factors, and neuromuscular activity in male basketball players, with a focus on vertical strength transfer (VST). In this semi-experimental study, 50 male basketball players (aged 16-18 years, with at least 2 years of experience) were randomly divided into three groups: combined lower-upper body plyometric training (LUBPT), upper body training (UBPT), and control (CON). The 8-week training program, 3 sessions per week, included hurdle jumps, depth jumps, and dynamic push-ups. Assessments included serum levels of growth hormone and testosterone, muscle thickness (elastography), muscle electrical activity (EMG), and sports performance (overhead medicine ball throw, Sargent jump, long jump) in pre- and post-tests.