Effects of Calcium â-Hydroxy-â-methylbutyrate (HMB) Supplementation During Resistance-Training on Markers of Catabolism, Body Composition and Strength

Calcium â-hydroxy-â-methylbutyrate (HMB) supplementation has been reported to reduce muscle catabolism and promote gains in fat-free mass and strength in subjects initiating training. However, whether HMB supplementation promotes these adapations in trained athletes is less clear. This study examined the effects of HMB (as the calcium salt) supplementation during resistance training (6.9 ± 0.7 hr × wk^-1) on markers of catabolism, body composition and strength in experienced resistance-trained males. In a double-blind and randomized manner, 40 experienced resistance-trained athletes were matched and assigned to supplement their diet for 28 d with a fortified carbohydrate/protein powder containing either 0, 3 or 6 g × d^-1 of calcium HMB. Fasting venous blood and urine samples, dual energy X-ray absorptiometer-determined body composition, and isotonic bench press and leg press one repetition maximums (1 RM) were determined prior to and following 28 d of supplementation. HMB supplementation resulted in significant increases in serum and urinary HMB concentrations. However, no statistically significant differences were observed in general markers of whole body anabolic/catabolic status, muscle and liver enzyme efflux, fat/bone-free mass, fat mass, percent body fat, or 1 RM strength. Results indicate that 28 d of HMB supplementation (3 to 6 g × d^-1) during resistance-training does not reduce catabolism or affect training-induced changes in body composition and strength in experienced resistance-trained males.

Key words:

Exercise - sport nutrition - ergogenic aids

References

• 1 Almada A, Kreider R, Ferreira M, Wilson M. Effects of calcium β-HMB supplementation with or without creatine during training on strength and sprint capacity.  FASEB J. 1997;  11 374
• 2 Fleck S J, Kraemer W J. Designing Resistance Training Programs. Champaign, IL; Human Kinetics 1987
• 3 Fuller N J, Jebb S A, Laskey M A, Coward W A, Elia M. Four-compartment model for assessment of body composition in humans: comparison with alternative methods and evaluation of the density and hydration of fat-free mass.  Clin Sci. 1992;  82 687-693
• 4 Horbes F F, Thomi F, Casez H P, Fonteielle J, Jaeger P. Impact of hydration status on body composition as measured by dual energy X-ray absorptiometry in normal volunteers and patients on haemodialysis.  Br J Radiol. 1992;  65 895-900
• 5 Kellie E E. Measurement of bone density with dual-energy x-ray absorptiometry (DEXA).  JAMA. 1992;  267 286-294
• 6 Klesges R C, Ward K D, Shelton M L, Applegate W B, Cantler E D, Palmeiri G MA, Harmon K, Davis J. Changes in bone mineral content in male athletes: Mechanisms of action and intervention effects.  JAMA. 1996;  276 226-230
• 7 Kraemer W J. General adaptations to resistance and endurance training. In: Baechle T (ed) Essentials of Strength Training and Conditioning. Champaign, IL; Human Kinetics 1994: 127-150
• 8 Kreider R, Ferreira M, Wilson M, Almada A. Effects of calcium β-HMB supplementation with or without creatine during training on body composition alterations.  FASEB J. 1997;  11 374
• 9 Mazess R B, Barden H S, Biseck J P, Hanson J. Dual-energy X-ray absorptiometry for total-body and regional bone-mineral and soft-tissue composition.  Am J Clin Nutr. 1990;  51 1106-1112
• 10 Miller P, Sandberg L, Fuller J C. The effect of intensive training and β-hydroxy-β-methylbutyrate (HMB) on the physiological response to exercise in horses.  FASEB J. 1997;  11 1683
• 11 Nair K S, Schwartz R G, Welle S. Leucine as a regulator of whole body and skeletal muscle protein metabolism in humans.  Am J Physiol. 1992;  263 (5 Pt 1) 934
• 12 Nissen S, Sharp R, Ray M, Rathmacher J A, Rice D, Fuller J C , Connelly A S, Abumrad N. Effect of leucine metabolite β-hydroxy-β-methylbutyrate on muscle metabolism during resistance-exercise training.  J Appl Physiol. 1996;  81 2095-2104
• 13 Nissen S, Faidley T D, Zimmerman D R, Izard R, Fisher C T. Colostral milk fat and pig performance are enhanced by feeding the leucine metabolite β-hydroxy-β-methylbutyrate to sows.  J Anim Sci. 1994;  72 2331-2337
• 14 Nissen S, Panton L, Fuller J, Rice D, Ray M, Sharp R. Effect of feeding β-hydroxy-β-methylbutyrate (HMB) on body composition and strength of women.  FASEB J. 1997;  11 150
• 15 Van Koevering M T, Dolezal H G, Gill D R, Owens F N, Strasia C A, Bucahnan D S, Lake R, Nissen S. Effects of β-hdyroxy-β-methylbutyrate on performance and carcass quality of feedlot steers.  J Anim Sci. 1994;  72 1927-1935
• 16 Van Koevering M T, Nissen S. Oxidation of leucine and β-ketoisocaproate to β-hdyroxy-β-methylbutyrate in vivo.  Am J Physiol. 1992;  262 (Endocrinol Metab 25) 27
• 17 Van Loan M D. Bioelectrical impedance analysis to determine fat-free mass, total body water and body fat.  Sports Med. 1990;  10 205-217
• 18 Vukovich M D, Stubbs N B, Bohlken R M, Desch M F, Fuller J C, Rathmacher J A. The effect of dietary β-hdyroxy-β-methylbutyrate (HMB) on strength gains and body composition changes in older adults.  FASEB J. 1997;  11 376
• 19 Wathen D. Load assignment. In: Baechle T (ed) Essentials of Strength Training and Conditioning. Champaign, IL; Human Kinetics 1994: 435-446