The Effect of a 12-week Plyometric Training on Growth Hormone, IGF-1 and Bone Health Indexes in Adolescent Boys

Abstract

Background: During adolescence, physical activity influences bone mass, which is determined by both genetic and environmental factors. Objectives: This study examines the effect of plyometric exercises on serum markers in male adolescents, including growth hormone, vitamin D, parathyroid hormone, phosphate, and calcium. Methods: The study involved a sample of 30 male adolescents aged 15 years ± 6 months. The participants were divided into two groups: The first group, named the plyometric group (PG), included 15 adolescents who underwent plyometric training sessions three times a week for a duration of 12 weeks. The second group, called the control group (CG), consisted of 15 adolescents who only attended their normal school lessons without any physical training. Resting levels of GH, IGF-1, vitamin D, calcium, phosphate, and PTH were measured before and 48 hours after the last training session, along with bone mass density (BMD) measurements of the femoral neck, lumbar spine, and total body. To evaluate power, the vertical Sargent jump test was used. Results: The results indicate that the PG demonstrated significant improvements in BMD, explosive strength, GH, IGF-1, and vitamin D levels compared to the CG group (P < 0.05). Changes in phosphate, calcium, and PTH were not significant in the PG compared to the CG after 12 weeks of plyometric training (P > 0.05). Conclusions: The 12-week plyometric program resulted in notable enhancements in bone health, explosive strength, and anabolic hormones such as GH and IGF-1, as well as 25-hydroxyvitamin D serum levels.