THE ACUTE EFFECT OF WHOLE-BODY LOW-FREQUENCY VIBRATION ON COUNTERMOVEMENT VERTICAL JUMP PERFORMANCE IN COLLEGE-AGED MEN

Lamont, HS, Cramer, JT, Bemben, DA, Shehab, RL, Anderson, MA, and Bemben, MG. The acute effect of whole-body lowfrequency vibration on countermovement vertical jump performance in college-aged men. J Strength Cond Res 24(12): 3433-3442, 2010-The purpose of this study was to examine the acute effects of whole-body vibration on jump performance. A total of 21 college-aged men, 18-30 years, recreationally resistance trained, were exposed to a total of 4 different acute whole-body low-frequency vibration (WBLFV) protocols (conditions 1-4), performing 2 protocols per testing session in random order. Exposures were all performed using high-amplitude (peak-peak 4-6 mm) and either 30 or 50 Hz for 30 continuous seconds, or 3 exposures of 10 seconds with 1 minute between exposures. Three countermovement vertical jumps (CMVJs) were performed before vibration (testing phase 1 or Tp1 and J1 the highest of 3 attempts) and at 3 separate time points postvibration (Tp2-4). Jump height (cm), peak power (P-max), peak power per kilogram of body mass (P-max kg(-1)), mean power (P-av), and mean velocity (V-av) were recorded. Repeated measures analysis of variance and analysis of covariance revealed no significant condition (C) or jump (J) differences for CMVJ height (cm) (p > 0.05). Analysis of percent change (Delta%) for CMVJ height (cm) revealed a significant Condition X Jump interaction, C4, J3 > C1, J3 (p = 0.009, mean diff 4.12%). Analysis of P-max and P-max kg(-1) revealed no significant Condition, Jump, or Condition X Jump interaction for the raw data or percent change (p. 0.05). Analysis of P-av (W) revealed significant differences for Condition (p = 0.031) but not for Jump (p = 0.226). There was a strong trend toward significance for Condition X Jump interaction (p = 0.059). C4 > C3 (p = 0.043, mean diff 23.78 W) and C1 (p = 0.038, mean diff 32.03 W). Analysis of V-av (m.s(-1)) revealed no significant main effects for Condition or Jump (p > 0.05) but found a significant Condition X Jump interaction (p = 0.007). C4, J6 > C2, J6 (p = 0.014, mean diff 0.05 m.s(-1)), and C3, J6 (p = 0.020, 0.05 m.s(-1)). WBLFV applied intermittently using 50 Hz appears to be more effective than other protocols using 30 and 50 Hz in facilitating select measures of CMVJ performance over a 17-minute time period post-WBLFV exposure. Practical manipulation of such a WBLFV "dose" may be beneficial to strength and conditioning practitioners wanting to acutely facilitate CMVJ and slow stretch shortening cycle performance while minimizing exposure time.