Effects of whole-body vibration and resistance training on knee extensors muscular performance

Whole-body vibration (WBV) is being promoted as an efficient complement to resistance training. The aim of this study was to investigate the effects of an 8-week program of WBV in combination with resistance training on knee extensors muscular performance. A group of 29 young adults (25 men, 4 women; age 21.8 +/- A 1.5) performed a WBV plus resistance training program (WBV + RES) or an identical exercise program in absence of vibration (placebo plus resistance training, PL + RES). Participants were evaluated for anthropometry, muscle strength (half-squat three repetition maximum, 3RM), knee extensors isokinetic dynamometry (180A degrees and 60A degrees A s(-1)) and counter-movement jump (CMJ). After the intervention, percent body fat significantly decreased 2.1% only in WBV + RES (P < 0.001), while muscle mass significantly increased in both groups (P < 0.01): 2.2 and 2.8 kg in PL + RES and WBV + RES, respectively. No significant differences were observed in isokinetic strength or CMJ, and 3RM significantly increased in both groups (P < 0.001): 64.2 kg (52% of baseline) in PL + RES, and 46.9 kg (43%) in WBV + RES. The addition of WBV to resistance training during 8 weeks, in recreationally active young adults, did not result in a larger muscular performance improvement compared to an identical exercise program in absence of vibration. Muscle mass also seemed to be equally affected with or without vibration, yet body fat could be exclusively decreased by WBV. Further research is required to clarify whether WBV, as a complement to resistance training, produces additional specific benefits.