Acute effects of block jumps in female volleyball players: The role of performance level

Abstract

Although the role of jumping ability in female volleyball players is well recognised, the effect of fatigue on this ability is not well known. The aim of the present study was to examine the effect of a series of block jumps (BJ) on jumping ability and whether it varies by performance level. Ten elite (EG) and 11 amateur (AG) female volleyball players performed a fatigue intervention consisting of 45 BJ, being tested for squat jump (SJ), countermovement jump (CMJ) and BJ before and after the intervention. Elasticity index (EI): (100 × (CMJ − SJ)/SJ) and upper limbs coordination index (ULCI): (100 × (BJ − CMJ)/CMJ) were calculated. After the intervention, EG showed a decrease of 4.40% in BJ height (p = 0.04; ES = 0.40), whereas AG presented an increase of 1.27%, which was not significant (p = 0.57; ES = 0.07). However, EG and AG presented no significant differences in SJ (p = 0.965 and p = 0.655) and CMJ (p = 0.742 and p = 0.211) when comparing baseline with post-intervention. Although EI and ULCI showed no significant differences after intervention in any group (AG: p = 0.989 and p = 0.114; EG: p = 0.242 and p = 0.205, respectively), AG presented a medium effect size (ES = 0.50) in EI and a small one in ULCI (ES = 0.37), also EG showed a medium-large effect in ULCI (ES = 0.75). These findings suggest that EG performance in BJ tends to decrease at the end of a specific jump training practice. Therefore, coaches and fitness trainers working with elite volleyball players should focus on exercises to maintain jumping ability during a match.