Acute effects of whole body vibration on heart rate variability in elderly people.

BACKGROUND: Whole body vibration (WBV) has been widely used as a modality for physical activity. In fact, WBV has been used for physical rehabilitation, and to improve muscle performance; but there is little information about its effects on heart rate variability (HRV).

AIM: The aim of this study was to evaluate the effect of vibration on HRV of the elderly using the vibratory platform.

METHODS: Eleven older adults (7 men, 4 women), aged between 60 and 75 years, were subjected to WBV. The study consisted of a single session of WBV with volunteers standing upright for 10 min on the oscillating platform, with frequency of vibration set at 20 Hz (displacement ± 6 mm; orbital vibration). Pre (baseline) and post-WBV electrocardiograph signals were acquired using a cardiac monitor; and data were statistically analyzed using paired Student's t-test or Wilcoxon test, as appropriate.

RESULTS: The results demonstrated an increase in SDNN (standard deviation (SD) beat-to-beat, N-N intervals), rMSSD (square root of the mean squared difference of successive N-Ns) and pNN50 (proportion of N-N50 divided by total number of N-Ns) post WBV (p = 0.032, p = 0.024 e p = 0.044, respectively), compared to baseline. The present study thus demonstrated that time domain variables (i.e., SDNN, rMSSD, and pNN50) increase post WBV.

CONCLUSIONS: Older individuals are at high risk of developing cardiovascular diseases. As seen in the study, WBV improves HRV; and may help reduce risk of cardiac ailments. Moreover, WBV does not require extensive physical activity on the part of the participant. This makes WBV potentially beneficial to the elderly population. Further studies on WBV using different frequencies and training schedules may improve its applicability in clinics.