Study aim: Comparison of the Effects of Jump Rope and Trampoline Training with a Control Group on Selected Biomechanical and Psychological Variables in Overweight Boys Aged 9–12 Years Design: This study is a randomized controlled clinical trial with a parallel, three-group design involving 45 overweight boys aged 9–12 years. After meeting the inclusion criteria, participants are randomly allocated in equal proportions to the jump rope, trampoline, and control groups, considering age and body mass index. Randomization is performed by an independent statistician, and researchers are blinded to group allocation. The trial phase is not applicable Settings and conduct: This study is conducted in Birjand among overweight boys aged 9–12 years. Following screening, participants are randomly allocated to three groups: jump rope, trampoline, and control. The intervention groups then receive the respective training programs, while the control group remains without intervention. After completion of the intervention period, the assessments are repeated. Assessors and the data analyst are blinded to group allocation. Participants/Inclusion and exclusion criteria: Participants are overweight boys aged 9–12 years. Inclusion criteria: general health, no disease, relevant medication use, musculoskeletal injury or pain, joint hypermobility (Beighton <4), ability to safely perform the tests, and parental consent. Exclusion criteria: disease or relevant medication use, history of regular sports participation, injury or surgery, relevant sensory disorders, Beighton ≥4, inability to safely perform the tests, and lack of parental consent. Intervention groups: Jump Rope, Trampoline, Control Main outcome variables: Static and dynamic plantar pressure; static and dynamic balance; center-of-pressure oscillations; time to stabilization; body image anxiety; loneliness; depression; life satisfaction; aggression