The acute effects of different whole-body vibration amplitudes and frequencies on flexibility and vertical jumping performance

Abstract 

Frequency and amplitude determine the training load of whole-body vibration (WBV) exercise and thereby possible neuromuscular adaptations. We investigated the effects of amplitude and frequency of a single bout of WBV on flexibility and squat jump performance (SJ) and the time-course of these effects. In the amplitude study, twenty-five females performed three vibration protocols (VPs) for 6min at frequency of 25Hz and amplitudes of 4mm, 6mm, and 8mm and one control protocol (CP). In the frequency study, eighteen females performed three VPs at 6mm amplitude and frequencies of 15Hz, 20Hz, and 30Hz and one CP. Flexibility and SJ were measured before, immediately-post and 15min recovery. All protocols were performed on a side-to-side alternating vibration plate. In the amplitude study, flexibility was improved (p<0.01) immediately-post in VP4, VP6, VP8 (31.8±8.2, 31.9±7.6, 31.5±7.9, respectively) and at 15min recovery (31.6±8.1, 31.5±7.9, 31.0±8.2, respectively) vs. pre-vibration (30.2±8.6, 30.3±8.1, 30.2±8.3, respectively), but remained unchanged in CP (30.6±8.3 immediately-post, 30.7±8.2 at 15min vs. 30.4±8.2 pre-vibration). In the frequency study, flexibility was improved (p<0.01) immediately-post in VP15, VP20, VP30 (31.5±5.2, 31.3±5, 31.7±5.3, respectively) and at 15min recovery (31.3±5.4, 31.3±5.0, 31.3±5.3, respectively) vs. pre-vibration (30.6±5.4, 30.2±5.7, 30.3±5.9, respectively), but not in CP (30.7±5.1 immediately-post, 30.6±5 at 15min vs. pre-vibration 30.5±5.7). There were no significant effects of amplitude or frequency on SJ. In conclusion, a single WBV bout using a side-to-side alternating vibration plate may increase flexibility which persists for at least 15min, without altering jumping performance. These effects were observed irrespective of frequency and amplitude.

Keywords: Squat jump, Sit and reach, Neuromuscular performance, Power, Dose–response