Abstract Objective: Obesity is a medical problem that increases the risk of health problems like diabetes. Hormones secreting from fat tissue, Leptin, are correlated with body mass index. Leptin reduces the person's appetite by acting on specific centers of their brain to reduce their urge to eat. And insulin, a hormone produced by the pancreas, is essential for regulating carbohydrates and the metabolism of fat. A positive relationship between leptin levels and insulin resistance in children showing in this study is to determine the effect of continuesendurance and interval-endurance on leptin serum levels and insulin resistance in over-weighted youths. Materials and Methods: This study is a semi-experimental design. Thirty boys were voluntarily selected as a matched two experimental groups and a control. Physical profiles included aged 16-19, BMI; 37.75 (±4.46) KG/M2, base functional capacity: 32.8 (±3.6) ml/kg/min which dividing by three equal groups: the submaximal training interval, a continuum and interval and control group performed the submaximal running program for six weeks on 3 D/W. The selected parameters were evaluated for an intervention pre and post-conditions. Results: weight and body mass index variables were decreased by about 2.5-3% after exercise intervention. Plasmatic leptin levels were reduced by about 45% in the continuum and interval control groups. HOMA-IR & QUICKI indexes altered in the EG (8.9 %, 7.8%) (Pvalue < 0.05). Conclusion: Presumably, 2 exercise program patterns lower than lactate threshold could change body composition profile, basal leptin level, and blood glucose /insulin concentrations, which probably induced changes in resistance to insulin.
