Various performance-enhancing effects from the same intensity of whole-body vibration training

Purpose: The purpose of this study was to compare the effects of an 8-week whole-body vibration training program in various frequency and amplitude settings under the same acceleration on the strength and power of the knee extensors. Methods: Sixty-four young participants were randomly assigned to 1 of 4 groups with the same acceleration (4 g): high frequency and low amplitude (n = 16, 32 Hz, 1 mm) group, medium frequency and medium amplitude (n = 16, 18 Hz, 3 mm) group, low frequency and high amplitude (n = 16, 3 Hz, 114 mm) group, and control (n = 16, no vibration) group. All participants underwent 8 weeks of training with body mass dynamic squats, 3 sessions a week. Results: The results showed that the high frequency and low amplitude group increased significantly in isometric contraction strength and 120 degrees/s isokinetic concentric contraction strength; the medium frequency and medium amplitude group increased significantly in 60 degrees/s and 120 degrees/s isokinetic strength of both concentric and eccentric contraction; and the low frequency and high amplitude group increased significantly in 60 degrees/s and 120 degrees/s isokinetic eccentric contraction strength. Conclusion: All frequency and amplitude settings in the 8-week whole-body vibration training increased muscle strength, but different settings resulted in various neuromuscular adaptations despite the same intensity. (C) 2017 Production and hosting by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).