β-Hydroxy-β-methylbutyrate Free Acid Reduces Markers of Exercise-Induced Muscle Damage and Improves Recovery in Resistance-Trained Men

Br J Nutr. 2013 Aug 28;110(3):538-44. doi: 10.1017/S0007114512005387. Epub 2013 Jan 3.

Abstract

The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of b-hydroxyb-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329%) than in the HMB-FA group (104%) (P¼0·004, d ¼ 1·6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9·1 (SEM 0·4) to 4·6 (SEM 0·5)) than in the HMB-FA group (9·1 (SEM 0·3) to 6·3 (SEM 0·3)) (P¼0·005, d ¼ 20·48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P¼0·08, d ¼ 0·12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biomarkers / metabolism
  • Creatine Kinase / blood
  • Dietary Supplements*
  • Exercise / physiology*
  • Humans
  • Male
  • Muscle Proteins / urine*
  • Muscular Diseases / drug therapy*
  • Muscular Diseases / etiology
  • Muscular Diseases / metabolism
  • Perception
  • Resistance Training*
  • Rest
  • Valerates / pharmacology
  • Valerates / therapeutic use*
  • Weight Lifting / physiology*
  • Young Adult

Substances

  • Biomarkers
  • Muscle Proteins
  • Valerates
  • beta-hydroxyisovaleric acid
  • Creatine Kinase