Journal of Exercise & Organ Cross Talk

Abstract The present study aimed to investigate the effect of a six-week metabolic conditioning training program on serum levels of insulin-like growth factor-1 (IGF-1) and glutathione peroxidase (GPX) in physically active young adults. This randomized controlled trial employed a pre-test–post-test design with a control group. A total of 23 physical education students (aged 18–24 years) were purposively recruited and randomly assigned to an exercise group (n = 12) or a control group (n = 11). The exercise group participated in a six-week metabolic conditioning circuit training program (three sessions per week, 18 sessions total), with progressive overload in volume and intensity. The control group maintained their usual daily activities. Blood samples were collected before and after the intervention to measure IGF-1 and GPX concentrations using validated ELISA kits. The primary between-group analysis using ANCOVA, after adjusting for baseline values, revealed no statistically significant difference between the groups in post-test IGF-1 levels (F(1,20) = 1.339, p = 0.261, η² = 0.063) or in post-test GPX levels (F(1,20) = 0.682, p = 0.419, η² = 0.033). A secondary within-group analysis showed a significant decrease in IGF-1 within the exercise group (p = 0.047); however, this finding must be interpreted with caution given the negative primary between-group comparison. No significant within-group changes were observed for GPX (p > 0.05). Anthropometric measures (weight and BMI) remained stable in both groups throughout the study. Based on the primary between-group comparisons, these findings indicate that six weeks of metabolic conditioning does not produce statistically significant changes in serum IGF-1 or GPX levels compared to a control condition in physically active young adults.