Effects Of Six Weeks Periodized Squat Training with Or Without WBLFV Upon Acute Responsivness To Vibration

Abstract

PURPOSE: The purpose of this study was to examine the effects of a 6 week, periodized squat training program, with (SQTV) or without (SQT) whole body low frequency vibration (WBLFV) versus an active control (CG) upon acute responsiveness to WBLFV over a seven week period. Measures of positive (Post Activation Potentiation (PAP)) or negative (Post activation Depression (PAD)) enhancement of jump performance were assessed and expressed as percent change (%) from pre WBLFV measures. METHODS: Participants, ranged in age from 18-30 years and were randomized into 1 of 3 groups (CG- control, n = 6; SQTV n = 13; SQT n = 11). SQTV and SQT performed Smith machine back squat training, twice per week with loads ranging between 55% and 90% 1-RM and sets ranging between 3 and 5. SQTV was also exposed to WBLFV for 30 sec (50 Hz 2-4 mm amplitude), rested 3 min, and then exposed to 3, 10 sec vibrations (50 Hz, amplitude 4-6 mm) at 1 min intervals in between sets of squats (four minutes rest between sets). All groups were exposed to an acute vibration protocol on weeks 1 (pre-training), 3 (mid-training) and 7 (post-training) consisting of 3 bouts of vibration lasting 10 seconds (50hz, 4-6mm amplitude) in-between performing 8 total jumps (2,30Dj and 2, 20SQj) pre and post WBLFV. Measures of jump height (cm) as well as dynamic power (Peak Power (Pmax), Peak Power per kilogram of body mass (Pmax/kg), and Mean Power (Pav)) were recorded for 30 cm depth jumps (30Dj) and 20kg squat jumps (20SQj). RESULTS: Repeated measures ANOVA and ANCOVA (Group (3) x Timepoint (3)) revealed no significant group by time point interactions for any of the outcome measures, however, percent change in Pmax for the squat jump trials was significantly greater for SQTV over SQT (p<0.01) as was jump height, Pmax and Pmax/kg for the depth jump trials (p<0.05). CONCLUSIONS: The addition of vibration to the 6 week resistance training program did appear to afford a preferential training adaptation resulting in more favourable acute responsiveness to WBLFV exposure for SQTV compared to SQT and CG for both jump conditions. Adaptations both within the CNS and PNS may have accounted for the differences seen. However, the frequency and amplitude used appeared to elicit highly variable acute responses within subjects which ranged from (PAP) to (PAD).