title: Eccentric exercise effect on blood oxidative-stress markers and delayed onset of muscle soreness.
abstract: OBJECTIVE
  This study examined the effects of a single bout of high-intensity eccentric exercise (EE) on blood protein carbonyls, glutathione status, and muscle damage indicators to ascertain whether blood markers of oxidative stress are elevated at the time delayed onset of muscle soreness (DOMS) occurs.
  
  
  METHODS
  Eight healthy men (26.5 +/- 1.5 yr) performed 60 eccentric contractions at approximately 135-150% dominant arm maximum isometric force (MIF) using their nondominant arm elbow flexors. DOMS, range of motion (ROM), MIF, and blood were obtained before, immediately after, and 24, 48, 72, and 96 h after the EE. Blood samples were analyzed for plasma creatine kinase (CK) activity, and protein carbonyls (PC), and erythrocyte glutathione status.
  
  
  RESULTS
  A significant decrease in MIF occurred at all times after the EE. ROM decreased from 24 to 96 h, and DOMS increased 24 to 72 h in the nondominant arm as indicated by a repeated measure ANOVA. Plasma CK activity peaked at 72 h (1620 +/- 500 IU x L(-1)) compared with baseline (154 +/- 27 IU x L(-1). Erythrocyte-reduced glutathione (GSH) concentration was not significantly affected by the EE but tended to decrease 23% by 24 h and continued at this level for 96 h. Oxidized glutathione (GSSG) and total glutathione were unchanged over time. A significant increase in plasma PC occurred at 24 and 48 h after eccentric exercise.
  
  
  CONCLUSIONS
  The results suggest that 60 EE at 135-150% MIF can result in DOMS, with decreased muscle function and increases in plasma PC at 24 and 48 h without alterations in blood glutathione status.
authors.affiliation: University of North Carolina Greensboro, Exercise and Sport Science Department, Greensboro, NC 27402-6169, USA.
authors.forename: Joohyung
authors.initials: J
authors.lastname: Lee
authors.forename: Allan H
authors.initials: AH
authors.lastname: Goldfarb
authors.forename: Mark H
authors.initials: MH
authors.lastname: Rescino
authors.forename: Sudhir
authors.initials: S
authors.lastname: Hegde
authors.forename: Steve
authors.initials: S
authors.lastname: Patrick
authors.forename: Kathy
authors.initials: K
authors.lastname: Apperson
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005978:Glutathione / Q000097:blood / Q000378:metabolism; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D010146:Pain / Q000378:metabolism; D010147:Pain Measurement; D013997:Time Factors
chemical_list: D003402:Creatine Kinase; D005978:Glutathione