title: Electrically stimulated resistance training in SCI individuals increases muscle fatigue resistance but not femoral artery size or blood flow.
abstract: METHODS
  Longitudinal.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the effect of lower extremity resistance training on quadriceps fatigability, femoral artery diameter, and femoral artery blood flow.
  
  
  METHODS
  Academic Institution.
  
  
  METHODS
  Five male chronic spinal cord injury (SCI) individuals (American Spinal Injury Association (ASIA): A complete; C5-T10; 36+/-5 years old) completed 18 weeks of home-based neuromuscular electrical stimulation (NMES) resistance training. Subjects trained the quadriceps muscle group twice a week with four sets of 10 dynamic knee extensions against resistance while in a seated position. All measurements were made before training and after 8, 12, and 18 weeks of training. Ultrasound was used to measure femoral artery diameter and blood flow. Blood flow was measured before and after 5 and 10 min of distal cuff occlusion, and during a 4-min isometric electrical stimulation fatigue protocol.
  
  
  RESULTS
  Training resulted in significant increases in weight lifted and muscle mass, as well as a 60% reduction in muscle fatigue (P = 0.001). However, femoral arterial diameter did not increase. The range was 0.44+/-0.03 to 0.46+/-0.05 cm over the four time points (P = 0.70). Resting, reactive hyperemic, and exercise blood flow did not appear to change with training.
  
  
  CONCLUSIONS
  NMES resistance training improved muscle size and fatigue despite an absence of response in the supplying vasculature. These results suggest that the decreases in arterial caliber and blood flow seen with SCI are not tightly linked to muscle mass and fatigue resistance. In addition, muscle fatigue in SCI patients can be improved without increases in arterial diameter or blood flow capacity.
authors.affiliation: Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Sabatier
authors.forename: L
authors.initials: L
authors.lastname: Stoner
authors.forename: E T
authors.initials: ET
authors.lastname: Mahoney
authors.forename: C
authors.initials: C
authors.lastname: Black
authors.forename: C
authors.initials: C
authors.lastname: Elder
authors.forename: G A
authors.initials: GA
authors.lastname: Dudley
authors.forename: K
authors.initials: K
authors.lastname: McCully
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000517:prevention & control*; D002320:Cardiovascular Physiological Phenomena; D004599:Electric Stimulation Therapy / Q000379:methods*; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology; D018908:Muscle Weakness / Q000209:etiology / Q000534:rehabilitation*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000503:physiopathology; D010809:Physical Fitness / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D016896:Treatment Outcome; D014463:Ultrasonography