(38) CHANGES IN UPPER AND LOWER-BODY FORCE CHARACTERISTICS FOLLOWING SHORT-TERM AUTOREGULATORY PROGRESSIVE RESISTANCE EXERCISE

Purpose: The purpose of this study was to examine changes in peak force (PF), and rate of force development (RFD) during an isometric mid-thigh pull (IMTP) and bench press (IBP) following a traditional versus relative 4-week APRE training program. Methods: Thirteen resistance trained males (age: 21.3 ± 2.4yrs; height: 174.7 ± 7.1cm; weight: 88.2 ± 21.3kg) were randomly separated into two group. Following, a 4-week APRE training program utilizing either traditional (a-APRE) adjustments based on absolute weight changes (±0 to 15 lbs) or relative (r-APRE) adjustments according to the Brzycki equation was implemented. Participants were taken to failure for 2 working sets at 85% of 1RM for compound lifts such as the squat, bench, deadlift, and overhead press. Two to three accessory exercises followed each major lift. Pre and post measures were recorded during an IMTP and IBP to compare PF and RFD during the early phase of force production (0-50ms, 51-100ms, and 101-150ms). Separate 2-way mixed factorial analyses of variance (ANOVA) were used to compare the pre and post measurements for PF during the IMTP and IBP between the r-APRE and a-APRE group. Furthermore, a 3-way mixed factorial ANOVA (group [r-APRE v a-APRE} x time [pre v post] x RFD [0-50ms v 51-100ms v 101-150ms]) was used to compare RFD in 50ms epochs during the early phase of the IMTP and IBP. Results: There were no significant group x time interactions or main effects for PF during the IMTP (p = 0.288, 0.655; respectively) or IBP (p = 0.711, 0.519; respectively). Regarding the RFD phases, there were no significant group x time x phase interactions for the IMTP (p = 0.982) or IBP (p = 0.506). However, there was a significant main effect during the IMTP (p = .013)(0-50ms [3922.664 ± 750.900], 51-100ms [6307.626 ± 852.083], 101-150ms [3610.552 ± 571.884]; mean ± SE) when collapsed by group and time. More specifically, the 51-100ms phase was significantly higher than the 0-50ms and 101-150ms phases. Additionally, there was a significant main effect during the IBP for the RFD phases (p = .049)(0-50ms [2850.734 ± 585.921], 51-100ms [3625.005 ± 588.636], 101-150ms [1530.068 ± 462.017]; mean ± SE) when collapsed by group and time. In particular, the 51-100ms phase was significantly higher than the 0-50ms phase. Conclusions: The a-APRE and r-APRE training protocols resulted in similar PF production following the training study. Significant increases in RFD were also seen in the first epoch of IMTP as well as a significant decrease in RFD from second to third epoch. This suggests that while both APRE training styles improve RFD to a significant degree, the absolute APRE training method may produce better peak force outcomes. Practical Applications: Considering the significant increases in PF and RFD, strength and conditioning coaches may consider using either a-APRE or r-APRE training strategies to improve athlete performance. Acknowledgements: None