title: Supplementation with beta-hydroxy-beta-methylbutyrate (HMB) and alpha-ketoisocaproic acid (KIC) reduces signs and symptoms of exercise-induced muscle damage in man.
abstract: This study examined the effects of beta-hydroxyl-beta-methylbutyrate (HMB) and alpha-ketoisocaproic acid (KIC) supplementation on signs and symptoms of exercise-induced muscle damage following a single bout of eccentrically biased resistance exercise. Six non-resistance trained male subjects performed an exercise protocol designed to induce muscle damage on two separate occasions, performed on the dominant or non-dominant arm in a counter-balanced crossover design. Subjects were assigned to an HMB/KIC (3 g HMB and 0.3 g alpha-ketoisocaproic acid, daily) or placebo treatment for 14 d prior to exercise in the counter-balanced crossover design. One repetition maximum (1RM), plasma creatine kinase activity (CK), delayed onset muscle soreness (DOMS), limb girth, and range of motion (ROM) were determined pre-exercise, at 1h, 24 h, 48 h, and 72 h post-exercise. DOMS and the percentage changes in 1RM, limb girth, and ROM all changed over the 72 h period (P < 0.05). HMB//IC supplementation attenuated the CK response, the percentage decrement in 1RM, and the percentage increase in limb girth (P < 0.05). In addition, DOMS was reduced at 24 h post-exercise (P < 0.05) in the HMB/KIC treatment. In conclusion, 14 d of HMB and KIC supplementation reduced signs and symptoms of exercise-induced muscle damage in non-resistance trained males following a single bout of eccentrically biased resistance exercise.
authors.affiliation: School of Life Sciences, Kingston University, Kingston-upon-Thames, United Kingdom.
authors.forename: Ken A
authors.initials: KA
authors.lastname: van Someren
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Edwards
authors.forename: Glyn
authors.initials: G
authors.lastname: Howatson
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood / Q000378:metabolism; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D007537:Isometric Contraction; D007651:Keto Acids / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries*; D016059:Range of Motion, Articular / Q000187:drug effects / Q000502:physiology; D019415:Torque; D014631:Valerates / Q000008:administration & dosage / Q000494:pharmacology*; D014891:Weight Lifting / Q000293:injuries / Q000502:physiology*
chemical_list: D007651:Keto Acids; D014631:Valerates; C004961:beta-hydroxyisovaleric acid; C013082:alpha-ketoisocaproic acid; D003402:Creatine Kinase