title: Effects of combined β-hydroxy-β-methylbutyrate (HMB) and whey protein ingestion on symptoms of eccentric exercise-induced muscle damage.
abstract: BACKGROUND
  The purpose of this study was to examine the effects of combined β-hydroxy-β-methylbutyrate (HMB) and whey protein ingestion on muscle strength and damage following a single bout of eccentric exercise.
  
  
  METHODS
  Eighteen untrained male subjects were assigned to HMB and Whey protein (HMB + Whey; 3 g/day HMB and 36.6 g/day whey protein, n = 6), HMB (3 g/day, n = 6), or whey protein (36.6 g/day, n = 6) groups. Ingestion commenced 7 days before non-dominant elbow flexor eccentric exercise (30 deg/sec, 6 reps × 7 sets) and continued until 4 days post-exercise. The maximal isometric strength, muscle soreness, plasma creatine kinase (CK), lactate dehydrogenase (LDH) were assessed pre-exercise, and at 1, 2, 3, and 5 days after exercise.
  
  
  RESULTS
  The change scores of maximal isometric strength significantly decreased at day 1, 2, and 5 in the whey protein group compared to pre value and that in HMB + Whey protein and HMB groups decreased at day 1 and 5. The muscle soreness significantly increased in the whey and HMB + Whey protein groups at day 3 compared to pre value (p < 0.05). CK and LDH significantly increased (time effect: p < 0.05) after exercise. However, all data were not significant difference among the groups.
  
  
  CONCLUSIONS
  These results suggest that ingestion of combined HMB and whey protein does not have a role to inhibit muscle strength loss and soreness, and decrease in muscle damage markers after eccentric exercise in comparison with HMB and whey protein alone.
authors.affiliation: Department of Hygiene and Public Health, Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya, Tokyo, Japan.
authors.forename: Minayuki
authors.initials: M
authors.lastname: Shirato
authors.affiliation: Laboratory of Health and Sports Sciences, Meiji Gakuin University, 1518 Kamikurata, Totsuka, Yokohama, Kanagawa Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tsuchiya
authors.affiliation: The Research Institute of Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya, Tokyo, Japan.
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Sato
authors.affiliation: Laboratory of Health and Sports Sciences, Meiji Gakuin University, 1518 Kamikurata, Totsuka, Yokohama, Kanagawa Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Hamano
authors.affiliation: Department of Hygiene and Public Health, Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Gushiken
authors.affiliation: Department of Hygiene and Public Health, Nippon Sport Science University, 7-1-1 Fukasawa, Setagaya, Tokyo, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kimura
authors.affiliation: Graduate School of Education, Okayama University, 3-1-1 Tsushimanaka, Kita, Okayama, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Ochi
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000187:drug effects*; D006801:Humans; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D053580:Muscle Strength / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D063806:Myalgia / Q000378:metabolism; D064133:Sports Nutritional Physiological Phenomena; D013997:Time Factors; D016896:Treatment Outcome; D014631:Valerates / Q000008:administration & dosage*; D000067816:Whey Proteins / Q000008:administration & dosage*
chemical_list: D014631:Valerates; D000067816:Whey Proteins; C004961:beta-hydroxyisovaleric acid; D003402:Creatine Kinase
keywords: Amino acids; Lengthening; Muscle soreness; Muscle strength