title: Effect of calcium β-hydroxy-β-methylbutyrate (CaHMB) with and without resistance training in men and women 65+yrs: a randomized, double-blind pilot trial.
abstract: BACKGROUND
  Evidence suggests CaHMB may impact muscle mass and/or strength in older adults, yet no long-term studies have compared its effectiveness in sedentary and resistance training conditions. The purpose of this study was to evaluate the effects of 24 weeks of CaHMB supplementation and resistance training (3 d wk(-1)) or CaHMB supplementation only in ≥65 yr old adults.
  
  
  METHODS
  This double-blinded, placebo-controlled, trial occurred in two phases under ad libitum conditions. Phase I consisted of two non-exercise groups: (a) placebo and (b) 3 g CaHMB consumed twice daily. Phase II consisted of two resistance exercise groups: (a) placebo and resistance exercise and (b) 3 g CaHMB consumed twice daily and resistance exercise (RE). Strength and functionality were assessed in both phases with isokinetic leg extension and flexion at 60°·s(-1) and 180°·s(-1) (LE60, LF60, LE180, LF180), hand grip strength (HG) and get-up-and-go (GUG). Dual X-Ray Absorptiometry (DXA) was used to measure arm, leg, and total body lean mass (LM) as well as total fat mass (FM). Muscle Quality was measured for arm (MQ(HG)=HG/arm LM) and Leg (MQ60=LE60/leg LM) (MQ180=LE180/leg LM).
  
  
  RESULTS
  At 24 weeks of Phase I, change in LE60 (+8.8%) and MQ180 (+20.8%) for CaHMB was significantly (p<0.05) greater than that for placebo group. Additionally, only CaHMB showed significant (p<0.05) improvements in total LM (2.2%), leg LM (2.1%), and LE180 (+17.3%), though no treatment effect was observed. Phase II demonstrated that RE significantly improved total LM (4.3%), LE60 (22.8%), LE180 (21.4%), HG (9.8%), and GUG (10.2%) with no difference between treatment groups. At week 24, only CaHMB group significantly improved FM (-3.8%) and MQHG (7.3%); however there was no treatment main effect for these variables.
  
  
  CONCLUSIONS
  CaHMB improved strength and MQ without RE. Further, RE is an effective intervention for improving all measures of body composition and functionality.
authors: Institute for Exercise Physiology and Wellness Research, University of Central Florida, Orlando, FL, USA. Electronic address: jeffrey.stout@ucf.edu.
authors: Jeffrey R
authors: JR
authors: Stout
authors: Abbie E
authors: AE
authors: Smith-Ryan
authors: David H
authors: DH
authors: Fukuda
authors: Kristina L
authors: KL
authors: Kendall
authors: Jordan R
authors: JR
authors: Moon
authors: Jay R
authors: JR
authors: Hoffman
authors: Jacob M
authors: JM
authors: Wilson
authors: Jeffery S
authors: JS
authors: Oliver
authors: Vikkie A
authors: VA
authors: Mustad
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology*; D001823:Body Composition / Q000187:drug effects / Q000502:physiology; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D009133:Muscular Atrophy / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D010865:Pilot Projects; D055070:Resistance Training; D014631:Valerates / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D014631:Valerates; C004961:beta-hydroxyisovaleric acid
keywords: AMPK; BUN; CaHMB and resistance exercise; DCER; DXA; Dynamic constant external resistance; Exercise; Fat mass; GUG; HG; LDH; MQ; Muscle quality; PT; RBC; RE; REHMB; REPLA; SGOT; SGPT; Sarcopenia; WBC; adenosine monophosphate kinase; blood urea nitrogen; dual-energy X-ray absorptiometry; get-up-and-go; hand grip; lactate dehydrogenase; muscle quality; peak torque; placebo and resistance exercise; red blood cells; resistance exercise; serum glutamic oxaloacetic transaminase; serum glutamic pyruvic transaminase; white blood cells; β-Hydroxy-β-methylbutyrate