Park BS, Henning PC, Grant SC, Lee WJ, Lee SR, Arjmandi BH, Kim JS. HMB attenuates muscle loss during sustained energy deficit induced by calorie restriction and endurance exercise.
Metabolism 2013;
62:1718-29. [PMID:
23876188 DOI:
10.1016/j.metabol.2013.06.005]
[Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 06/06/2013] [Accepted: 06/07/2013] [Indexed: 01/24/2023]
Abstract
OBJECTIVE
To investigate the efficacy and underlying mechanisms of β-hydroxy-β-methylbutyrate (HMB) on body composition, muscle mass and physical performance under catabolic versus normal training conditions.
MATERIALS/METHODS
Mice were divided into four groups (n=10/group): (1) ALT=ad libitum+trained (1 h/d for 3 d/wk); (2) ALTH=ALT+HMB (0.5 g/kg BW/d); (3) C=calorie restricted (-30%)+trained (6 h/d, 6 d/wk); and (4) CH=C+HMB. Repeated in vivo assessments included body composition, grip strength and sensorimotor coordination before and after the experimental protocol, while in vitro analyses included muscle wet weights, expression of selected genes and proteins regulating muscle mass, and myofiber cross-sectional area. ANOVAs were used with significance set at p<0.05.
RESULTS
ALTH had greater lean mass than ALT and sensorimotor function increased in ALTH, but decreased in ALT under normal training conditions. Grip strength decreased only in C, but was maintained in CH. Gastrocnemius mass and myofiber CSA were greater in CH than C following catabolic conditions. Gastrocnemius atrogin-1 mRNA expression was elevated in C but not in CH compared to all other groups whereas atrogin-1 protein levels showed no significant changes.
CONCLUSION
HMB improves body composition and sensorimotor function during normal training and attenuates muscle mass and strength loss during catabolic conditions.
Collapse