title: Motor unit control strategies of endurance- versus resistance-trained individuals.
abstract: BACKGROUND
  We examined motor unit (MU) control properties of resistance-trained (RT) and endurance-trained (ET) individuals.
  
  
  METHODS
  Five RT (age 25 ± 4 years) and 5 ET (age 19 ± 1 years) subjects participated. Surface electromyography (EMG) data were recorded from the vastus lateralis during isometric trapezoid muscle actions at 40% and 70% of maximal voluntary contraction. Decomposition and wavelet transform techniques were applied to the EMG signals to extract the firing events of single MUs and EMG intensity across the frequency spectrum.
  
  
  RESULTS
  There were significant differences between RT and ET for the mean MU firing rate and derecruitment threshold versus recruitment threshold relationships and EMG intensity at various wavelet bands during the linearly increasing, steady force, and linearly decreasing segments of the trapezoid contraction.
  
  
  CONCLUSIONS
  MU behavior is altered as a function of training status and is likely the result of differences in the physical properties of the MU.
authors: Neuromechanics Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, Kansas, 66045, USA.
authors: Trent J
authors: TJ
authors: Herda
authors: Neuromechanics Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, Kansas, 66045, USA.
authors: Jacob A
authors: JA
authors: Siedlik
authors: Neuromechanics Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, Kansas, 66045, USA.
authors: Michael A
authors: MA
authors: Trevino
authors: Neuromechanics Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, Kansas, 66045, USA.
authors: Michael A
authors: MA
authors: Cooper
authors: Neuromechanics Laboratory, Department of Health, Sport, and Exercise Sciences, University of Kansas, 1301 Sunnyside Avenue, Room 101BE, Lawrence, Kansas, 66045, USA.
authors: Joseph P
authors: JP
authors: Weir
mesh_terms: D000293:Adolescent; D000328:Adult; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D055070:Resistance Training / Q000379:methods; D055815:Young Adult
keywords: EMG frequency; MU control; exercise; motor unit; training; wavelet transform