No abstract

Volleyball involves movements with and/or without horizontal approaches (i.e., spike jumps, jump setting, blocking). The 5-jump test (5JT) was suggested to assess lower limb explosive power of athletes competing in some disciplines (e.g., soccer, judo, running). It appears that no previous study has investigated the 5JT performance components in volleyball players. This study aimed to test the relationship between 5JT performance and two specific laboratory tests for explosive power (i.e., countermovement jump [CMJ] and squat jump [SJ]). Forty volleyball players (boys, mean age: 12.4 ± 0.8 years) were tested for 5JT, CMJ, and SJ tests. 5JT performance was expressed in absolute terms (m), and relative to leg length (5JTLL) and body mass (5JTBM). The SJ and CMJ tests were evaluated using the optojump photoelectric cells and the following data were collected: peak power (Pp) of jump (W, W.kg-0.67), peak jumping force (Fpeak, N), peak jumping velocity (Vpeak, m/s), peak heights of CMJ and SJ (CMJH and SJH, respectively, cm). Only significant ( p < .05) Pearson product-moment correlations ( r) > 0.30 were considered. 5JT performance was significantly correlated with SJ, Vpeak ( r = 0.90), SJH ( r = 0.88), Pp [W.kg-0.67 ( r = 0.86), W ( r = 0.72)], Fpeak ( r = 0.45); and CMJ, Vpeak ( r = 0.82), CMJH ( r = 0.80), Pp [W.kg-0.67 ( r = 0.89), W ( r = 0.85)], Fpeak ( r = 0.73). 5JTLL values were significantly related to SJ, Pp [W ( r = 0.81), W.kg-0.67 ( r = 0.74)], Vpeak ( r = 0.82); and CMJ, Pp [W ( r = 0.73), W.kg-0.67 ( r = 0.84)], Vpeak ( r = 0.75), Fpeak ( r = 0.67)]. 5JTBM values were significantly related to SJ, Pp (W, r = −0.43). To conclude, in youth volleyball players, the 5JT may be viewed as an explosive strength diagnostic instrument under field circumstances.

No abstract

This study compared the effects of different sprint ball-based training programs on fitness-related performances in youth soccer players. Forty male players (age: 15.2 ± 0.6 yrs) participated in a short-term (8 weeks) randomized parallel fully controlled training study, with pre-to-post measurements. Players were randomly assigned to 3 sprint ball-based training groups: training with combined sprint (performing linear and change of direction sprints; CST), or using linear sprint (LST), or performing sprint with change of direction (CODT) and to a control group (CONT). Pre- and post-training players completed a test battery involving linear sprinting (10 and 20 m, and flying 10 m), 505 test (COD), 15 m test with ball (CODB), countermovement jump test (CMJ test) and maximal oxygen consumption (VO2max). All physical performance’ variables improved after the training intervention (all p < 0.05; ES ≥ 0.2). No main effect of groups was observed in linear sprinting, CMJ and VO2max (p > 0.05; ES < 0.2). A training group main effect was found (p < 0.0001; ES = 0.50) for COD with CODT induced better performance than LST and CONT (all p <0.0001; ES > 0.8). Also, a training group main effect (p = 0.009; ES = 0.35) was found for CODB with CODT elicited better performance than LST and CONT (all p = 0.001; ES > 0.80). Our findings suggest that ball-based training programs were more effective to improve fitness levels in youth players during the in-season period and that CODT modality was more effective to improve COD and CODB performances.