title: Spring-mass behavior and electromyographic activity evolution during a cycle-run test to exhaustion in triathletes.
abstract: OBJECTIVE
  To evaluate spring-mass (SM) behavior and associated electromyographic (EMG) activity during a run to exhaustion following a cycle exercise in trained triathletes.
  
  
  METHODS
  Ten triathletes completed four tests: a cycling test to determine V˙O(2max); a running test to determine the lactate threshold (LT); a 5 min control run at LT (C-Run) followed after a total recovery period by a cycle-to-run session to exhaustion [30 min of cycling at ∼80% V˙O(2max) followed by a run until exhaustion at LT (T-Run)]. SM behavior and EMG signals in nine lower limb muscles were recorded throughout the running sessions.
  
  
  RESULTS
  Immediately after cycling, leg stiffness was 12.1% higher than its C-Run value and a concomitant increase of EMG activity of knee extensors was observed during pre-contact. Throughout T-Run, leg stiffness decreased by 7.3%, while knee extensors and ankle flexors activities decreased during pre-contact and braking phases. No significant variations in SM parameters and no significant increase of muscle activity were reported between C-Run and the end of T-Run.
  
  
  CONCLUSIONS
  SM behavior during the cycle-run test was consistent with EMG activity changes. Cessation of exercise was not associated with significant alterations of stiffness values and EMG activity.
authors.affiliation: Research Department, National Institute of Sport, Expertise and Performance, 75012 Paris, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Le Meur
authors.forename: S
authors.initials: S
authors.lastname: Dorel
authors.forename: G
authors.initials: G
authors.lastname: Rabita
authors.forename: T
authors.initials: T
authors.lastname: Bernard
authors.forename: J
authors.initials: J
authors.lastname: Brisswalter
authors.forename: C
authors.initials: C
authors.lastname: Hausswirth
mesh_terms: D000328:Adult; D056352:Athletes; D001642:Bicycling / Q000502:physiology*; D004576:Electromyography; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D035002:Lower Extremity / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D012420:Running / Q000502:physiology*
chemical_list: D019344:Lactic Acid