title: Eccentric resistance training intensity may affect the severity of exercise induced muscle damage.
abstract: BACKGROUND
  The aim of the present study was to assess the role of eccentric exercise intensity in the development of and recovery from delayed onset muscle soreness (DOMS).
  
  
  METHODS
  Using a cross-over study design, 15 healthy, male college students were tested on two occasions. The training stimulus consisted of an exhaustive series of eccentric muscle contractions of the elbow flexors at either 100% (high intensity) or 50% (low intensity) of the individual concentric one-repetition maximum. Blood samples were taken at baseline as well as 24, 48, 72 and 96 hours postexercise, and analyzed for creatine kinase, myoglobin, interleukin-6 and prostaglandin-2. Additionally, upper arm circumference (CIRC) and DOMS-related sensation of pain (PAIN) were measured.
  
  
  RESULTS
  Following high intensity training, CIRC was significantly greater (P=0.007). Further, creatine kinase, myoglobin and interleukin-6 tended to be higher, although the main effect of the factor "intensity" just failed to reach significance (creatine kinase: P=0.056, myoglobin: P=0.064, interleukin-6: P=0.091). No differences were found for prostaglandin-2 (P=0.783) and PAIN (P=0.147).
  
  
  CONCLUSIONS
  When performed at greater intensity, fatiguing eccentric resistance exercise of the elbow flexors leads to greater muscle swelling and, potentially, increases in serum markers reflecting lesions in the muscle's cellular membrane.
authors.affiliation: Department of Sport and Exercise Physiology, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria - timothy.hasenoehrl@meduniwien.ac.at.|Department of Physical Medicine and Rehabilitation, Medical University of Vienna, General Hospital of Vienna, Vienna, Austria - timothy.hasenoehrl@meduniwien.ac.at.
authors.forename: Timothy
authors.initials: T
authors.lastname: Hasenoehrl
authors.affiliation: Department of Sport and Exercise Physiology, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wessner
authors.affiliation: Department of Training and Movement Science, Center for Sport Science and University Sports, University of Vienna, Vienna, Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Tschan
authors.affiliation: Study Lab G.m.b.H., Vienna, Austria.
authors.forename: Claudia
authors.initials: C
authors.lastname: Vidotto
authors.affiliation: Department of Physical Medicine and Rehabilitation, Medical University of Vienna, General Hospital of Vienna, Vienna, Austria.
authors.forename: Richard
authors.initials: R
authors.lastname: Crevenna
authors.affiliation: Institute for Sport Science, University of Innsbruck, Innsbruck, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Csapo
mesh_terms: D000328:Adult; D001132:Arm / Q000473:pathology; D003402:Creatine Kinase / Q000097:blood; D018592:Cross-Over Studies; D004550:Elbow / Q000502:physiology; D004551:Elbow Joint / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000293:injuries*; D063806:Myalgia / Q000503:physiopathology*; D009211:Myoglobin / Q000097:blood; D055070:Resistance Training / Q000379:methods*
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D009211:Myoglobin; D003402:Creatine Kinase