(06) INVESTIGATING THE STRETCH-SHORTENING CYCLE FATIGUE RESPONSE TO A HIGH-INTENSITY OVERREACHING PHASE OF TRAINING IN COLLEGIATE MEN’S BASKETBALL

Background: Using force-plate derived measures of vertical jump performance, to assess stretch-shortening-cycle (SSC) efficiency is common in sport science, however there is limited evidence as to which tests and measures may be most sensitive toward neuromuscular fatigue.

Purpose: The aim of this study was to explore the SSC fatigue response to a one-week high-intensity fatiguing phase of training in collegiate basketball players.

Methods: Sixteen male basketball players, currently on a roster at a NCAA Division-I university participated in this study (body mass=93.2 ± 11.3kg, hheight=195.6 ± 10.4cm). Lasting six weeks, the first three weeks of the study were used to establish reliability data, as well as baseline external workload exposure. During each baseline week, athletes performed three countermovement jumps [(CMJ) slow SSC] trials, and two 10-5 hop test (fast SSC) trials on separate days. During and following the fatiguing training period, CMJs and 10-5 hop tests were performed on the same day. The fatiguing training period consisted of five consecutive days during which athletes participated in basketball-specific, high-intensity drills. During the fatiguing training period, CMJs and 10-5 hop tests were performed on two days, 6 hours following the training session (A1 and A2). Following the fatiguing training period, tests were performed at 72 hours post (P72h), as well as 1-, and 2-weeks post (P1W and P2W). To analyze our data, mixed effect models were fit with the respective force-time metric as the dependent variable, time as the fixed factor, and athlete ID as the random effect intercept.

Results: Compared to the weekly training sum at baseline, during the high-intensity training phase, athletes experienced very large increases in the weekly sum for selected external workload metrics (ES = 1.44 to 3.16), suggesting athletes experienced fatigue acutely, as well as potentially longer lasting. Vertical jump data showed that in the CMJ, traditional metrics such as jump height (F=41.1, p< .001), as well as metrics reflecting movement strategy such as braking velocity (F=26.8, p< .001), were sensitive to increases in high-intensity workload exposure. The 10-5 hop test suggested a fatigue-induced loss of tolerance to ground impact reflected by performance reductions in metrics related to jump height (F=28.4, p< .001) and reactive strength qualities (F=23.6, p< .001). Example fatigue sensitivity data are visualized in the figure below.

Conclusion: Results showed the acute and chronic fatigue sensitivity of selected force-time metrics from a slow and a fast SSC movement task. PRACTICAL APPLICATIONS: Our findings emphasize that when monitoring neuromuscular fatigue, variables and assessments may not be looked at individually, but rather as part of a more global monitoring approach. Further, the individuality of recovery timelines with regards to task- and time-specificity should be considered when interpreting variables.

Acknowledgements: The authors would like to thank the Joseph Tsai and Clara Wu foundation for their assistance in completing this project.