title: Effects of endurance training on the maximal voluntary activation level of the knee extensor muscles.
abstract: OBJECTIVE
  The aim of this study was to investigate the neural adaptations to endurance training, and more specifically the adaptation of the cortical voluntary activation of the knee extensor (KE) muscles.
  
  
  METHODS
  Sixteen sedentary men were randomly allocated into an endurance training (n = 8) or a control group (n = 8). All subjects performed a maximal aerobic speed test (MAS) before and immediately after the training period. Training lasted 8 weeks and was based on endurance running. During Pre- and Post-training testing sessions, maximal voluntary contraction (MVC) was measured and voluntary activation (VA) was calculated via peripheral nerve (PNS) and transcranial magnetic stimulations (TMS) superimposed to MVC. Electromyographic activity (EMG) of the KE muscles was also measured during MVC, PNS (M-wave) and TMS (motor evoked potentials-MEP). The cortical silent period following TMS was also assessed.
  
  
  RESULTS
  Despite a significant improvement in endurance running performance, as suggested by the increase of MAS in the training group (Pre 15.4 ± 1.6 vs. Post 16.4 ± 1.6 km·h(-1)), endurance training did not affect MVC or VA as measured with PNS and TMS. Similarly, the EMG of KE muscles during MVC did not show any significant changes. Furthermore, the MEP amplitude and the duration of the silent period also remained unchanged after endurance training.
  
  
  CONCLUSIONS
  The present study suggests an 8-week endurance-training program does not generate adaptations of neural factors in sedentary subjects.
authors.affiliation: UBIAE (INSERM U902), Faculty of Sport Sciences, Val d'Essonne University, Evry, France.
authors.forename: F
authors.initials: F
authors.lastname: Zghal
authors.forename: V
authors.initials: V
authors.lastname: Martin
authors.forename: A
authors.initials: A
authors.lastname: Thorkani
authors.forename: P J
authors.initials: PJ
authors.lastname: Arnal
authors.forename: Z
authors.initials: Z
authors.lastname: Tabka
authors.forename: F
authors.initials: F
authors.lastname: Cottin
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D019054:Evoked Potentials, Motor; D006801:Humans; D007537:Isometric Contraction; D007717:Knee / Q000294:innervation / Q000502:physiology*; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D010525:Peripheral Nerves / Q000502:physiology; D055070:Resistance Training; D057185:Sedentary Behavior; D050781:Transcranial Magnetic Stimulation