(64) ANALYZING CHANGES IN COUNTERMOVEMENT JUMP PERFORMANCE AMONGST NCAA D1 MALE BASKETBALL PLAYERS: A PRELIMINARY STUDY

Purpose: To investigate the differences in countermovement jump (CMJ) performances before and after games compared to baseline performances amongst elite college basketball players. Methods: Nine NCAA Division 1 men's basketball players (age = 21.1 ± 1.5 years, height = 202.2 ± 7.8 cm, weight = 94.1 ± 10.2 kg) performed weekly CMJ testing throughout the preseason phase of training to determine their baseline level of performance. After the preseason, athletes jumped one day before (GD-1) and two days after every game (GD+2) to track the performances of the players throughout the competitive season. Each athlete completed two to three maximum effort jumps with their hands on their hips and were cued to jump as high and fast as possible. The CMJ trials were performed on dual force plates sampling at 1000 Hz and the raw force-time data were used to determine jump height (JH), countermovement depth (CMD), braking mean force (BMF) and duration (BD), propulsion mean force (PMF) and duration (PD), time to take-off (TTT), and modified reactive strength index (mRSI). The performance variables were averaged across baseline (20 sessions), GD-1 (9 sessions), and GD+2 (10 sessions) testing and were compared using a series of one-way repeated measures ANOVA with Bonferroni post hoc tests. In addition, Hedge’s g effect sizes were calculated to examine the magnitude of the differences between testing time points. Results: CMJ performance data and post hoc analyses are displayed in Table 1. There was a significant difference for TTT (p = 0.002) between baseline, GD-1 (g = 1.39), and GD+2 (g = 1.15); however, the differences in JH (p = 0.133), CMD (p = 0.547), BMF (p = 0.393), PMF (p = 0.057), BD (p = 0.926), PD (p = 0.909), and mRSI (p = 0.187) were not statistically significant and trivial-small in magnitude. Conclusions: There were moderate-large decreases in TTT from baseline testing to the competitive season; however, the difference between GD-1 and GD+2 was small and not practically meaningful. In contrast, there were no statistical or meaningful differences in JH, CMD, BMF, PMF, BD, PD, or mRSI between the baseline, GD-1, and GD+2 testing sessions. Practical Applications: A well-designed strength and conditioning program paired with appropriate practice intensity and durations and recovery may allow for a meaningful decrease in TTT from the preseason to the competitive season in Division I men’s basketball players. From an athlete monitoring standpoint, JH, CMD, BMF, PMF, BD, PD, or mRSI may not have been sensitive enough to display meaningful changes in performance; however, further research should monitor the differences on an individual basis. Moreover, researchers may consider examining the differences between high-minute versus low-minute players to determine what variables are sensitive to performance changes throughout the competitive season. Acknowledgements: None