The Effects of 4 weeks beta-hydroxy-beta-methyl butyrate (HMB) supplementation on body composition, inflammatory response and muscle damage after eccentric exercise in untrained males

Amino acids and their metabolite through inhibition of muscle proteolysis and enhancement of protein synthesis, exert anti-catabolic effects. In the context of exercise and recovery, several studies have reported the beneficial effects of beta-hydroxy-beta-methylbutyrate (HMB), a derivative of the branched-chain amino acid leucine (LEU). However, few studies have evaluated the efficacy of HMB intake among untrained subjects and also the duration of supplementation in previous studies is relatively short. In the present study, the effects of HMB on muscle damage, body composition and inflammation were investigated. Forty untrained males were supplemented with HMB (3 g/ day) or placebo for 4 weeks. The concentrations of creatine kinase (CK) and lactate dehydrogenase (LDH) were assessed at baseline, and at 1, 24, and 48 hours after exercise. The values of CK and LDH in HMB group were significantly lower (p= 0.001) compared to the placebo group. HMB ingestion was also able to decrease inflammatory biomarkers including C-reactive protein (CRP) and interleukin-6 (IL-6). Additionally HMB significantly improved the body composition, as it was reflected by decreased body fat percentage. In conclusion, the results of this study showed that HMB supplementation may attenuate the exercise-induced muscle damage and have beneficial effects on post exercise recovery.