Poster Topical Area: Sports Nutrition
Poster Board Number: 234
Background: Numerous nutritional strategies have been developed in the attempt to optimise the responses to resistance training (RT). In this respect, the effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation on RT-induced muscle gains has received a great deal of attention with equivocal findings in the literature, some of which have been attributed to the different forms of HMB available. Differential bioavailability between oral Ca HMB (HMB-Ca) and HMB-Free Acid (HMB-FA) have been credited to the controversial results among studies. In fact, a series of studies with HMB-FA have shown impressive gains in strength and muscle mass, although these results are disputable.
Objectives: To compare the effects of 12 weeks of HMB-FA and HMB calcium salt (HMB-Ca) supplementation along with resistance training on lean body mass (LBM) and fat mass (FM) in resistance-trained adults.
Methods: Forty-five resistance-trained men participated in this double-blind, randomised, placebo controlled study. They received HMB-FA (3g.day-1; n=15), HMB-Ca (3g.day-1; n=15) or placebo (corn starch, 3g.day-1; n=15). During the 12-week supplementation period, they undertook a supervised resistance training program (2 sessions per muscular group per week). Before and after treatments, body composition was determined by dual X-ray absorptiometry (DXA). Data was analysed using mixed models (SAS 9.1).
Results: No effects of training or supplementation were observed for body mass (group-by-time interaction: p=0.354). All groups increased LBM following the training intervention (main effect of time: p=0.354). All groups increased LBM following the training intervention (main effect of time: p=<0.001) and a marginally significant group-by-time interaction was observed (p=0.09). Contrast analysis revealed that the HMB-FA had marginally larger increases in LBM in comparison with HMB-Ca (p=0.07) with this reaching significance in the comparison with Placebo (p=0.03). No differences between HMB-Ca and Placebo were found.
Conclusions: There was a clear effect of training on LBM. The effects of HMB on LBM are less clear and seemed to be occur only with HMB-FA supplementation. This suggests that HMB-FA may have a minor positive effect on LBM.
Aline Cristina Capparelli Tritto
University of Sao Paulo
Sao Paulo, Sao Paulo, Brazil