Vertical Jump Performance Predicts Selection Of Young Talented Volleyball Players For the Junior National Team

Abstract

PURPOSE: To determine whether anthropometric measurements and fitness test results can discriminate between selected and non-selected junior volleyball players. METHODS: Forty three male junior volleyball players (age: 15.0±0.7 yrs) took part in training camp and underwent a selection procedure by coaches of the junior national team. Anthropometric data (body height, body mass and body height with extended arm) and fitness tests results (countermovement jump (CMJ), block jump, spike jump, 10m sprint and 505 agility test) were obtained. Four expert volleyball coaches of the national team evaluated and graded the players in a scale from 0 to 100 during their participation in a volleyball tournament. The coaches selected the best 23 players on the basis of their score (selected players; n=23, height: 186±5 cm, body mass: 72±10 kg) (non-selected; n=20, height: 188±3 cm, body mass: 69.5±7.5 kg). A linear discriminant analysis was conducted on the selected and non-selected groups to determine if the anthropometric and fitness test data could predict the coaches’ selection. Anthropometric and fitness test data of the two groups were compared using independent samples t-tests. Statistical significance was set at p<0.05. RESULTS: Selected players had higher coaches’ scores compared to the non-selected (83.9±7.2 vs. 65.3±7.5, p<0.05). There were significant differences between selected and non-selected in only in vertical jumps (CMJ: 40.5±6.7 vs. 34.4±3.6 cm, block jump: 43.6±6.9 vs. 36.9±3.5 cm, spike jump: 72.8±10.3 vs. 63.4±3.8 cm, all p<0.05), but not in any other anthropometric or fitness test parameter. The multivariate analysis yielded a discriminant function (Wilk’s lambda= 0.69, χ2= 15.12, p=0.001, η2=0.12). CMJ was the main test result that highly loaded the discriminant function (r=0.85). Cross validation results showed that selection was correctly predicted in 31 out of the 43 selected athletes (predictive accuracy: 72.1%). CONCLUSIONS: Vertical jumping ability may be used as an important parameter that largely determines success, since it may discriminate between selected and non-selected junior volleyball players.