The effect of four weeks of intense plyometric and intermittent exercises with zinc supplementation on the serum levels of growth hormone and like growth factor in male volleyball players.

The purpose of this research was to compare two methods of plyometric and intense interval training during four weeks of zinc supplementation on two growth factors, growth hormone and serum-like growth factor of adolescent volleyball players at the age of skeletal growth spurt. For this purpose, the number of 57 active and healthy teenage volleyball players (age: 13.81±0.94 years, height: 1.77±0.08 m, weight: 59.28±10.04 kg, and BMI: : 18/76 ±2/13 kg/m2) were selected as subjects and randomly divided into six groups including: 1- plyometric exercise and zinc supplement consumption (10 people), 2- plyometric exercise and placebo consumption (8 people), 3- Volleyball training and taking zinc supplements (9 people), 4-Volleyball training and placebo control group (11 people), 5- HIT training group and taking zinc supplements (10 people) and 6- HIT training and placebo group (9 people) were divided. The training schedule was three sessions a week. The supplement groups also received 15 mg gluconate tablets produced by Nature Made in England and the pseudo drug groups received tablets containing starch and fructose for daily consumption. The inter-group results showed a significant increase in growth hormone and pseudo-growth factor levels after four weeks in the research groups (P<0.000). The post-test results showed the difference between the control group and other study groups (P<0.05). No significant difference was observed between training groups on growth values (P>0.05). Due to the increase in the content of growth factors in young volleyball athletes, both plyometric and intense interval training methods as well as zinc are recommended