Effects of amplitudes of whole-body vibration training on left ventricular stroke volume and ejection fraction in healthy young men

OBJECTIVE The aim of this study was to evaluate the effects of different whole-body vibration (WBV) training amplitudes on left ventricular stroke volume and ejection fraction in healthy young men. METHODS A total of 24 healthy men (age 21.71±1.49 year, height 176.17±6.61 cm, weight 70.73±10.08 kg, BMI 22.36±3.57 kg/m2, and body surface area 1.87±0.13 m2) were divided into two groups: high and low amplitude vibration (n=12). The vibration training consisted of 8 weeks of WBV 3 times a week with amplitudes of 2 or 4 mm and progressive frequencies from 20 Hz with increments of 5 Hz weekly. As outcome measures, left ventricular stroke volume and ejection fraction at baseline and after 8 weeks were evaluated. Mann-Whitney U test was used for the comparison between groups; Wilcoxon signed-ranks tests were used to compare pretest and post-test results in each group. A p value less than 0.05 was considered significant. RESULTS Whole-body vibration training with low amplitude (2 mm) caused an numerically increase in stroke volume (pre-test: 72.42±14.34; post-test: 78.42± 23.19 cm3; p=0.06) and ejection fraction (pre-test: 65.22±3.41; post-test: 67.00±4.18%; p=0.52). So; the increase was not significant. In the high-amplitude (4 mm) group, post-test results were nearly unchanged compared to the pre-test results. No significant difference was evident between groups. CONCLUSION The intensity and volume of whole-body vibration training were not enough to affect systolic function.