[The relationship between power, speed and agility in youth volleyball players].

Introduction . In youth volleyball players, no previous study has investigated the relationships between the components of the force-velocity test (FVt) and those of the horizontal jump approach, speed test, and agility test. Aim . To determine the relationships that exist between lower-body power measured via a laboratory test ( i.e. ; FVt) and some field tests [horizontal jump ( i.e. ; 5-jump test (5JT)), speed test ( i.e. ; 20-m sprint) and agility test ( i.e. ; changing of direction (CoD)] in youth volleyball players. Methods . Thirty-one youth volleyball players were investigated for CoD, 5JT, and absolute/relative peak leg power (Ppeak) during the FVt. Speeds (s) during a 20-m sprint were measured at 5, 10, and 20 m (T 5 , T 10 and T 20 , respectively). 5JT performance was expressed in absolute terms (5JTA, m), and relative to leg length and body-mass. Pearson correlation coefficient (r) was performed among the variables of the FVt, 20-m sprint, CoD, and 5JT tests. "r" was considered "high" when it was > 0.70, "good" when it was between 0.50-0.70, "fair" when it was between 0.30-0.50, and "weak or no association" when it was < 0.30. Results . This study identified i) "high" correlations between FVtPpeak (W) and 20-m sprint [T5 (r=-0.858), T10 (r=-0.707), and T20 (r=-0.762)], and CoD (r=-0.745), ii) "good" correlations between FVtPpeak (W.kg) and 5JTA (r=0.531), and iii) "fair" correlations between FVtPpeak (W) and 5JTA (r=0.499), between FVtPpeak (W.kg-0.67) and 5JTA (r=0.489), and 20-m sprint [T5 (r=-0.370), T10 (r=-0.364)]. Conclusion . CoD, 20-m sprint, and 5JT can be used to evaluate lower limb explosive power in youth volleyball players.