Analysis of jump load during a volleyball season in terms of player role.

Objectives: The aim of this study was to analyze the jump load performed by top-level volleyball players during an entire training season in terms of the player role, training period, type of daily training, and quality of opposition in the subsequent match.

Design: Longitudinal panel observational study.

Methods: The total number of jumps performed by players was recorded through 174 training days distributed in 32 weeks during the 2016/2017 season (pre-season, 5 weeks; in-season, 27 weeks). The players role were classified as middle-blocker, outside-hitter, opposite and setter (the libero was omitted). A generalized mixed linear model was performed (with Bonferroni post hoc test at p<0.05) to assess the effect of training variables and the repeated-measures data of players' jumps along various training days. Additionally, the effect sizes at 95% confidence intervals were calculated to compare the jump load between players' role and training variables.

Results: The results showed a significant and moderate higher amount of jumps performed by middle-blockers regardless the type of macro- or micro-cycle, the micro-cycle phase, the type of training and the quality of match opposition. Contrarily, the setter performs the least jump load in all variables analyzed. Only the players' role, macro-cycle and micro-cycle phase had significant effects on the player's jump load variation along the season.

Conclusions: This information could be useful to guide the monitoring and preparation process for coaches and physical trainers. These values allow differentiating between players' role and could be used as references values in order to avoid injuries whereas performance increase along the season.