Volleyball is a dynamic physical game that does not have a definite match duration but is based on high tempo, quickness, strength, flexibility, endurance and jumping. The aim of this study is to research the relationship between isokinetic knee strength and jumping height in young male volleyball players. 8 male volleyball players aged between 18-22 participated in the research voluntarily. In the study, the physical characteristics of the subjects (body height, body weight, body mass index) were determined, vertical jump heights were measured and at low (60°.s-1) and high (300°.s-1) speeds, the right and left knee flexion/extension concentric isokinetic strength test was applied. Data was analyzed with paired sample t-test and Pearson correlation coefficient test was used to determine the relationship between vertical jump and isokinetic strength (p<0.05).The right and left knees peak torque of the athletes were compared at low and high angular speeds and no significant difference was found. A significant positive correlation was detected between the jumping height and the right knee peak torque at low angular speed (r =.817, p<0.05). This result can be explained by the fact that quadriceps femoris, which is the biggest muscle of the lower extremity, is in the foreground during the jumps that volleyball players perform frequently. It may be advisable to give importance to leg strength training to increase the jump height.

The aim of this study was to examine the effect of eight-week plyometric training on the agility of elite male volleyball players. A total of 28 elite male volleyball players were included in the study; the experimental group consisted of 14 (mean age 29.1±4.3) players and the control group was composed of 14 (mean age 20.2±1.4) players. The experimental group performed lower extremity plyometric training for twice a week for eight weeks after the warm-up exercises conducted before volleyball training, in addition to regular volleyball training. The control group, on the other hand, performed only volleyball training for eight weeks. T-drill agility test was used in the study. Measurements were performed in two separate test periods, pre-and post-test. SPSS 22.0 statistical package program was used for data analysis. Paired sample t-test was conducted to investigate whether there were intragroup statistically significant differences or not, while an independent sample t-test (p<0.05) was used for inter-group comparisons. The experimental group showed statistically significant differences between pre-test and posttest data whereas the control group did not show any statistically significant differences between pre-and post-test (p<0.05). In conclusion, it was found that eight-week lower extremity plyometrics training significantly increased the volleyball players' agility. .