Impact of Congested Match Schedules on Countermovement Jump Metrics in Elite Volleyball Players.

Abstract: Rebelo, A, Loturco, I, Pereira, JR, Martinho, DV, Valente-dos-Santos, J, and Broek, GV. Impact of congested match schedules on countermovement jump metrics in elite volleyball players. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to assess the impact of a congested match schedule on various countermovement jump (CMJ) metrics recorded across the braking, transfer, propulsive, and flight phases of the CMJ. Fourteen male elite volleyball players were monitored across 7 microcycles, with CMJ assessments conducted at 14 time points using portable force plates. Repeated measures analysis of variance with Bonferroni post hoc tests and coefficient of variation (CV) analysis were used to analyze the data. The CVs for all metrics indicated a moderate variability between microcycles and low variability between the beginning and end of the weeks. Significant variability was observed in key performance metrics, including peak propulsive power (p < 0.001, partial eta squared [ηp2] = 0.336), peak propulsive velocity (p = 0.005, ηp2 = 0.207), propulsive phase duration (p = 0.008, ηp2 = 0.197), and jump momentum (p = 0.019, ηp2 = 0.225), across microcycles. These findings indicate that these CMJ metrics may be used as sensitive indicators of fatigue and performance changes during intense training and competitive periods. The total score of athleticism, calculated by averaging a set of standardized scores from multiple tests or repeated measures of the same test, for the propulsive and flight phases, proved to be particularly useful in providing a comprehensive view of the neuromuscular status. This emphasizes the importance of recording and analyzing a range of CMJ metrics to optimize training and recovery strategies in elite volleyball players.