(15) VARIATIONS OF HEX BAR DEADLIFTS ON POST-ACTIVATION PERFORMANCE ENHANCEMENT IN COLLEGIATE BASEBALL ATHLETES

Purpose: This study aimed to examine if a concentric-only hex bar deadlift (CHBDL) would produce a similar post-activation performance enhancement (PAPE) effect as a full-range-of-motion hex bar deadlift (THBDL) and mitigate perceived measures of fatigue and soreness in collegiate athletes. Methods: 19 NCAA Division I baseball athletes (age=20.63±1.74 years, height=185.24±4.90 cm, body mass=84.88±8.21 kg, body fat percentage=12.79±5.35%, one-repetition maximum [1RM]: CHBDL=221.97±22.35 kg, THBDL=232.63±21.41 kg) completed the study. A repeated measures design with randomized assignment and counterbalanced order was utilized. Over two weeks, two variations of a hex-bar deadlift, CHBDL and THBDL, were added into a typical priming protocol used by the strength and conditioning practitioner. For both protocols, session one consisted of collecting pre-test measures of perceived fatigue (VAS-F), perceived soreness (VAS-S), countermovement jump height (CMJ), overhead medicine ball throw speed (MBT), and 27.42-meter dash with a 9.144-meter split (9MS) recorded. VAS-F and VAS-S were collected prior to the warm-up. Following the warmup, participants rotated through the CMJ and MBT, and the 27MD was performed last for everyone. Following pre-testing, participants completed their assigned protocol (CHBDL or THBDL) and reported a post-session rating of perceived exertion (RPE). The standardized warm-up and protocol were constructed by the team’s strength and conditioning practitioner. Both protocols were prescribed five sets of decreasing target velocity ranges and an increasing load (i.e., 1x5 reps at 0.52-0.57 m/s, 2x3 reps at 0.47-0.52 m/s, and 2x1 rep at 0.43-0.47 m/s) that were estimated to equal 72-85% of 1RM (1). Session two for each protocol occurred 24 hours following priming, and all pre-testing measures were repeated. SPSS was used to run separate two-way repeated measures ANOVAs to investigate differences between time and protocol for CMJ, MBT, 9MS, 27MD, VAS-F, and VAS-S. Protocol RPE differences were investigated using paired-sample t-tests. Effect sizes were reported as Cohen’s d. Statistical significance was set a priori at p< 0.01 to account for the number of tests performed. Results: No significant interactions for time and protocol or main effects for protocol existed for any of the measures (p >0.01). A significant main effect for time was present in the 9MS (-0.025s, p=0.004, d=0.45) and VAS-F (+7.434 mm, p=0.002, d=0.62), but not for the CMJ, MBT, 27MD, or VAS-S (p >0.01). RPE showed no significant differences between protocols (p >0.01). Conclusions: Post-priming 9MS times were significantly faster than pre-priming times for both CHBDL and THBDL protocols. Perceived fatigue was also higher 24 hours post-priming for both protocols. No significant changes in CMJ, MBT, 27MD, and VAS-S were observed. Practical Applications: The findings of this study suggest that, for athletes of similar characteristics to this study, both CHBDL and THBDL are viable strategies to improve short-distance, acceleration-biased sprint performance 24 hours post-priming without an increase in perceived muscle soreness. This is especially beneficial when needing to conduct a priming session prior to travel for a competitive event and/or when same-day priming is not feasible. Acknowledgements: None