title: Effects of amplitudes of whole-body vibration training on left ventricular stroke volume and ejection fraction in healthy young men.
abstract: 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.
  
  
  CONCLUSIONS
  The intensity and volume of whole-body vibration training were not enough to affect systolic function.
authors.affiliation: Department of Physical Education, Science and Research Branch, Islamic Azad University; Tehran-Iran. phdghazalian@gmail.com.
authors.forename: Farshad
authors.initials: F
authors.lastname: Ghazalian
authors.forename: Laleh
authors.initials: L
authors.lastname: Hakemi
authors.forename: Lotfali
authors.initials: L
authors.lastname: Pourkazemi
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Akhoond
mesh_terms: D005081:Exercise Therapy; D017079:Exercise Tolerance / Q000502:physiology*; D006801:Humans; D008297:Male; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*; D014732:Vibration / Q000627:therapeutic use*; D055815:Young Adult