title: Resistance training performed at distinct angular velocities elicits velocity-specific alterations in muscle strength and mobility status in older adults.
abstract: The purpose of this study was to compare the effects of high and low velocity knee extension training on changes in muscle strength and mobility status in high-functioning older adults.
  
  
  
  Twenty-six (16 female, 10 male) older adults (mean age of 65) were randomized to either 6weeks of low velocity resistance training (LVRT) performed at 75°/s or high velocity resistance training (HVRT) performed at 240°/s. Both groups performed 3 sets of knee extension exercises at maximal effort, 3 times a week. Muscle strength was assessed through a range of testing velocities on an isokinetic dynamometer. Mobility status was assessed with the short physical performance battery (SPPB) and myosin heavy chain (MyHC) transcript levels were quantified via qRT-PCR.
  
  
  
  From baseline to post-training, there were several significant (P<0.05) differences in muscle strength and functional characteristics in LVRT (n=13) and HVRT (n=13) groups. From baseline to post-training, MyHC-α mRNA and MyHC-IIa mRNA showed a significant (P<0.05) increase within HVRT but MyHC-IIx mRNA did not change significantly. Our results demonstrate HVRT provides a greater number of muscular enhancements when compared to LVRT, particularly under conditions of high velocity muscle contraction.
  
  
  
  HVRT is emerging as the optimal training stimulus for the older adult. The present study demonstrates, in addition to increased strength and functional outcomes, HVRT elicits a potentially therapeutic (i.e., slow to fast) transcriptional response in MyHC.
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, IA 50010, United States.
authors.forename: Davis A
authors.initials: DA
authors.lastname: Englund
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, IA 50010, United States.
authors.forename: Rick L
authors.initials: RL
authors.lastname: Sharp
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50010, United States.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Selsby
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50010, United States.
authors.forename: Shanthi S
authors.initials: SS
authors.lastname: Ganesan
authors.affiliation: Department of Kinesiology, Iowa State University, Ames, IA 50010, United States. Electronic address: wfranke@iastate.edu.
authors.forename: Warren D
authors.initials: WD
authors.lastname: Franke
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009119:Muscle Contraction; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D055070:Resistance Training / Q000379:methods*; D012737:Sex Factors; D016037:Single-Blind Method; D014481:United States
chemical_list: D018995:Myosin Heavy Chains
keywords: Exercise interventions; High-velocity resistance training; Isokinetic; Mobility limitations; Muscle power