The Effect of Three Methods of Plyometric Training on Leg and Hand of Explosive Strength in Adolescent Male Volleyball Players

The aim of this study was to investigate the effect of three methods of plyometric training on explosive strength of hands and legs of adolescent male volleyball players. This semi-experimental study was conducted as a field with three groups. The population consisted of all adolescent volleyball players of Hidaj and Khorramdareh cities (mean age 16.14±1.02 yr, height 177.36±5.92 cm, weight 67.91±8.148 kg, BMI 21.55±2.08 kg/m , VO2max 54.36±4.92 ml/kg/min). Statistical sample consisted of 36 adolescent volleyball players who were divided randomly into three groups (each group 12 subjects) (lower limb, upper limb and combined). At first, a pretest of dependent variables was administered for the three groups. Then, all three groups participated in a plyometric training program for 8 weeks and 2 sessions per week and finally posttests were conducted. Data were analyzed using SPSS20 and analysis of variance with repeated measures at a significance level of P≤0.05. The findings showed that the main effect and the interaction were significant in all three variables (block jump, spike jump and medicineball throw) (P≤0.05). There was a significant different only in medicineball throw among the groups (P=0.036). Bonferroni post hoc test results showed a significant difference between upper and lower limb in favor of upper limb group (P=0.043). Finally, the results showed that according to the good progress of combined group in the three variables and a concurrent need of volleyball for explosive strength of upper and lower limbs, combined training method was suitable.