This investigation evaluated the effects of oral β-Hydroxy-β-Methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g · day−1 of HMB or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p = .01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.
G. Slater is with the Sports Medicine Sports Science Division of the Singapore Sports Council, National Stadium, Singapore 397718. D. Jenkins is with the School of Human Movement Studies at The University of Queensland, Brisbane, Australia 4072. P. Logan, H. Lee, and A.G. Hahn are with the Department of Physiology at the Sports Science Sports Medicine Centre, Australian Institute of Sport, Canberra, Australia 2616. M. Vukovich is with the Human Performance Laboratory at South Dakota State University, Brookings, SD 57007. J.A. Rathmacher is with the Department of Animal Science at Iowa State University, Ames, IA 50011-3150.