Serum levels of Insulin-like growth factor-1 (IGF-I) as an indicator associated with aerobic and anaerobic fitness assessment in adolescent boys

Abstract

Background: Insulin-like growth factor -1 (IGF-I) has a variety of roles, But the abundance of scientific evidence indicates that it is a metabolic biomarker associated with indicators of physical fitness and health. The present study examined the relationship between serum levels of IGF-I and aerobic fitness, anaerobic capacity and body fat percent, systolic, and diastolic blood pressure before and after the eight weeks of high intensity intermittent training (HIIT) in adolescent boys. Methods: In this experimental study, 22 adolescent boys in a randomly and double-blinded design were allocated in two equal groups: HIIT group (N=11) and control group (N=11). Training programs were conducted 3-4 times per week for 8 weeks. The HIIT program consisted of 6-8 running sprints (30-60 seconds) with a 3.5-4 min recovery. Mentioned indicators assessments were performed 18-24 hours pre and post intervention. Results: IGF-1, Maximum Oxygen uptake (VO2max(, Peak Power Output (PPO) and mean power output (MPO) were significantly higher after 8 week HIIT than the pre-exercise training evaluations (P 0.05). Conclusion: The IGF-I can be used as an indicator to assess the fitness of adolescent boys.