Metabolic Responses to Whole-Body Vibration Varying in Frequency and Amplitude

Abstract

Whole-body vibration (WBV) has been shown to provide neurological potentiation, thereby enhancing muscular activity. To date, how WBV might influence energy metabolism has not been fully elucidated. PURPOSE: This study was undertaken to assess the effect of various vibratory loads on metabolic responses during WBV and subsequent aerobic exercise. METHODS: Sixteen subjects (21.0±2 yr) including eight men and eight women underwent six WBV sessions that differed in frequency (e.g., 30-Hz, 40-Hz, and 50-Hz) and amplitude (e.g., 1-2 mm and 2-3 mm) in a randomized order. In each WBV session, subjects performed 10 sets of 10 body weight squats with each set lasting 30 sec and 1-min rest period between sets on a vibration platform with a vibration load that represented one of the six frequency-amplitude combinations. Each vibration treatment was immediately followed by 20 min of a constant load cycle exercise at 65% VO2peak. Oxygen uptake (VO2) and respiratory exchange ratio (RER) were measured throughout WBV and subsequent exercise. The average VO2 and RER of both WBV and exercise were analyzed using 2-way (frequency × amplitude) repeated measure ANOVA followed by pairwise comparisons involving Bonferroni correction. RESULTS: During WBV, VO2 demonstrated a progressive increase as a function of vibration frequency and amplitude. A significant main effect of amplitude was observed for VO2 in l·min-1 (F=6.326, p=0.02) and ml·kg-1·min-1 (F=5.497, p=0.03). The highest VO2 occurred at 50-Hz and 2-3 mm (e.g., 13.1±2.4 ml·kg-1·min-1). During subsequent exercise, VO2 responded similarly to that seen in WBV, and there were trends (p = 0.08-0.10) towards a greater VO2 at higher frequencies or amplitudes. No effects of vibration frequency or amplitude on RER were found during either WBV or subsequent exercise. CONCLUSIONS: WBV can augment metabolic responses in a load-dependent manner when administered concurrently with body-weight squats. Such a stimulating effect seems to persist during aerobic exercise that commences immediately after WBV.