Lauren R Tapp, Joseph F Signorile

The purpose of this pilot study was to evaluate the effectiveness of whole body vibration (WBV) training as a modality for inducing changes in body composition, cardiovascular condition, and muscular strength in sedentary postmenopausal women. WBV training was compared with other training regimens, ie, aerobic training and circuit resistance training, commonly used to promote weight loss, cardiovascular conditioning, and muscular strength. Postmenopausal women (aged 48-60 years) were randomly assigned to WBV training, circuit resistance training, or aerobic training. Participants trained three times per week for 8 weeks. The training regimens were progressive in nature, with increases in training intensity and duration occurring throughout the 8-week period. Body composition was assessed using dual-energy X-ray absorptiometry analyses. A modified Bruce treadmill protocol was used to assess aerobic capacity (VO2peak) and time to peak exhaustion. Upper and lower body strengths were determined by one repetition maximum (1-RM) chest and leg presses, respectively. Variables were analyzed using separate 3 (exercise mode) × 2 (time) repeated-measures analysis of variance with effect sizes due to the small sample size. No significant main effects or interactions were seen for any body composition variable; however, moderate to large effect sizes (η (2)=0.243 and η (2)=0.257) were detected regarding interactions for percent body fat and lean body mass favoring aerobic training and circuit resistance training. For VO2peak, no significant main effects or interactions were detected (time, η (2)=0.150; P=0.11; time × group, η (2)=0.139; P=0.30); but a significant time effect was observed for time to peak exhaustion (η (2)=0.307; P=0.017). A significant interaction for upper body strength (η (2)=0.464; P=0.007), and main effect for time in lower body strength (η (2)=0.663; P=0.0001) was detected. Post hoc analysis indicated a significant increase in upper body strength for circuit resistance training (P=0.023) and a decrease for WBV training (P=0.015). Our results indicate that WBV may not be an effective alternative to traditional training with regard to body composition or aerobic capacity, but could have a positive impact on lower body strength.