Vibration training and body fat: a comment on Artero et al. (2011)

Abstract

I read with interest the recent publication of Artero and colleagues “EVects of whole-body vibration and resistance training on knee extensors muscular performance” (Artero et al. 2011). The introduction to this work concludes by asserting that a central aim was to compare resistance versus resistance + whole-body vibration (WBV) training modalities to determine “any additional eVect on knee extensors muscular performance compared to an identical exercise program without vibration” (emphasis mine). Due to the analysis conducted, the central and signiWcant conclusion to this paper was not presented in this manner. The control group lost 1.3% body fat (BF) from baseline (p = 0.116) and the WBV group somewhat more (2.1% BF, p < 0.001). Crucially, these results were not compared to each other, the authors’ rationale being that the baseline result for the control group was not signiWcant. Regardless of the signiWcance of the control condition, I submit that it is much more appropriate to derive an interaction term between these results; hence testing the magnitude of an additional eVect, rather than a simple within-group eVect. Fjeldstad et al. (2009) performed precisely this kind of analysis in a pre-post study on additive WBV training in sedentary women. If this result is robust to the above correction, I suggest that it is unusual. The study cited by Artero et al. (2011) in support of this result (Da Silva et al. 2007) reported statistically signiWcant changes between WBV and nonWBV groups in both energy expenditure and respiratory exchange ratio, which may represent a potential mechanism for decreasing fat mass. However, their protocol involved using repeated bouts of signiWcant external resistance and exercising to near-muscular failure during WBV exercise rather than an additive approach. Relevant to resistance training, vibration shows an equivocal ability to improve balance, jump height, and muscle power (see Rittweger 2010 for review), but there is no reliable evidence that it individually improves body composition (Cochrane 2011). Rittweger et al. (2001) estimated the increase in speciWc oxygen uptake at 4.5 mL kgi1 mini1 during WBV, which amounts to an approximate adipose reduction of approximately 10 g per hour under standard assumptions (Rittweger 2010). While the parameters of the training vary somewhat, the overall training load in Artero et al. (2011) is approximately 2 h total across 8 weeks. Thus, it would seem either the central result is artifactual or requires an entirely separate mechanism whereby WBV has a facilitatory eVect on subsequent resistance training, which in turn aVects energy expenditure. This is a possibility, as the relationship between WBV and other exercise modalities has received insuYcient research attention.