Acute effects of varying whole body vibration exposure on jump performance of amateur club volleyball players

Abstract

Whole body vibration (WBV) has been shown to result in rapid improvement in muscle strength and power. However, WBV studies have utilised sedentary individuals as participants and research is limited on athletes for whom strength and power are their primary assets in sport. Utilising WBV as part of a training programme, or as a warm up protocol prior to games, enables athletes to improve their power output during game time. The objective of this study was to measure the acute effects of varying low and high frequencies (0Hz, 30Hz, 35Hz, 40Hz, and 50 Hz) set at low (2-4mm) and high (4-6mm) displacements of WBV for 30 seconds on the countermovement jump (CMJ) performance in amateur club volleyball players. A single-blinded repeated-measures study design was used. Thirty amateur club volleyball men (averaging age, 25.33 ± 5.86 years; height, 1.82 ± 0.073 m; weight, 84.06 ± 13.23 kg) completed maximal CMJs pre- and post-WBV in the quarter squat position for 30 seconds. Participants were randomly exposed to nine frequency/displacement WBV exposure settings. Countermovement jump performances were measured pre and post each WBV exposure. Measurements included peak jump height (cm); power (w/kg) and velocity (cm/sec). Results showed no significant CMJ changes post-WBV at frequencies of 30Hz, 35Hz, 40Hz and 50Hz, set at a low displacement. However, post-WBV exposure mean power was significantly (p=0.048) increased at a frequency of 35Hz, at a high displacement. Mean velocity also significantly (p=0.044) increased at a frequency of 40Hz and at a high displacement post- WBV exposure. It can be concluded that an acute 30-second bout of WBV, set at 35Hz and 4-6mm displacement, significantly improves explosive jumping performance in comparison to other frequencies.

Keywords: Countermovement jump, whole body vibration, volleyball, frequency.