title: Physical performance and markers of muscle damage following sport-specific sprints in male collegiate soccer players: repeated bout effect.
abstract: BACKGROUND
  This is the first study to examine the repeated bout effect (RBE) on physical performance parameters in an athletic population. Protocols used by previous studies to induce muscle injury and assess performance following injury, are dissimilar from those utilized by physically trained individuals or are impractical in relation to athletic performance. The present study uses a sport specific protocol to study the effects of exercise induced muscle damage (EIMD) on physical performance to provide a more systematic analysis of the extent of muscle injury.
  
  
  METHODS
  Thirty two male collegiate soccer players were randomly assigned into either a repeated bout group (N.=16) or control group (N.=16). The repeated bout group performed 2 bouts of sport-specific sprints separated by 14 days. The control group performed a single bout of the same sprint protocol. Maximum voluntary isometric contraction for quadriceps (MVCQ) and hamstrings (MVCH), knee range of motion (ROM), thigh circumference, muscle soreness, plasma creatine kinase (CK) and lactate dehydrogenase (LDH), in addition to physical performance parameters-speed, agility and power were measured before, 24, 48 and 72 hours following the sprinting bouts.
  
  
  RESULTS
  MVCQ, MVCH, ROM, thigh circumference, CK, LDH and agility showed significant group x time interaction (P<0.05), suggesting lesser decrements and better recovery profile for the repeated bout group. Muscle soreness showed a main effect for group (P<0.001).
  
  
  CONCLUSIONS
  The physical performance parameters (speed, agility and power) are less affected by EIMD as compared to other markers and therefore did not demonstrate RBE.
authors.affiliation: Center for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (Central University) New Delhi, India - jamoizpt@gmail.com.
authors.forename: Shalini
authors.initials: S
authors.lastname: Verma
authors.forename: Jamal A
authors.initials: JA
authors.lastname: Moiz
authors.forename: Mohammed Y
authors.initials: MY
authors.lastname: Shareef
authors.forename: Mohammed E
authors.initials: ME
authors.lastname: Husain
mesh_terms: D000293:Adolescent; D054874:Athletic Performance / Q000502:physiology*; D015415:Biomarkers / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood; D015444:Exercise / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction; D007719:Knee Joint; D007770:L-Lactate Dehydrogenase; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D063806:Myalgia / Q000209:etiology / Q000503:physiopathology; D052097:Quadriceps Muscle; D016059:Range of Motion, Articular / Q000502:physiology; D012420:Running / Q000502:physiology*; D012916:Soccer / Q000502:physiology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase