Effects of a 8-Week Combined Walking and Elastic Band Exercise Program on Body Composition, Grip Strength, and the FGF21–IGF-1–Insulin Axis in Obese Adolescents

This study investigated the effects of a 8-week combined walking and elastic band exercise program on body composition, grip strength, metabolic risk factors, and the fibroblast growth factor 21 (FGF21)– insulin-like growth factor-1 (IGF-1)–insulin axis in obese adolescents. Twenty male adolescents with obesity (body mass index ≥ 85th percentile) were randomly assigned to an exercise group (EG, n = 10) or a control group (CG, n = 10). The EG participated in a combined exercise program consisting of walking and elastic band resistance training for 50 minutes per session, five times per week for 8 weeks, while the CG maintained their usual lifestyle. Body composition, grip strength, blood pressure, lipid profiles, glucose, FGF21, IGF-1, insulin, and HOMA-IR were measured before and after the intervention. Data were analyzed using repeated-measures ANOVA. Significant group-by-time interactions were observed for body weight, body fat mass, waist circumference, systolic and diastolic blood pressure, triglycerides, glucose, and IGF-1 (p < .05). The EG showed significant reductions in body fat mass, waist circumference, blood pressure, triglycerides, and glucose, along with significant improvements in grip strength and IGF-1 levels, whereas the CG exhibited unfavorable changes in triglycerides and glucose. No significant interaction effects were found for FGF21, insulin, or HOMA-IR. A 8-week combined exercise program effectively improved body composition, metabolic risk factors, and growth-related hormonal profiles in obese adolescents.