title: Ibuprofen does not affect serum electrolyte concentrations after an ultradistance run.
abstract: OBJECTIVE
  To determine the effects of ibuprofen on serum electrolyte concentrations after a 160 km running race.
  
  
  METHODS
  Twenty nine subjects (mean (SD) age 47.9 (7.4) years) ingested 600 mg ibuprofen the day before, and 1200 mg ibuprofen during, a 160 km competitive trail running race (approximately every 4 h in 200 mg doses). Twenty five control subjects (mean (SD) age 46.8 (10.3) years) avoided ingestion of ibuprofen before or during the race. Blood was drawn on the day before the race and immediately after the race. Serum biochemical profiles were analysed by a clinical laboratory. Significant effects of treatment and time were determined with a general linear model with repeated measures.
  
  
  RESULTS
  Subjects in the two groups did not differ by age, training volume, race experience, body mass index, body fat, or finishing time (25.8 (3.3) vs 25.6 (3.9) h). Body weight did not change significantly over the race (measured before, mid-race (90 km), and after). Ibuprofen ingestion did not significantly affect any of the serum markers including creatine kinase (p = 0.16). A significant decrease in serum sodium (p = 0.006), potassium (p = 0.001), chloride (p<0.001), calcium (p<0.001), albumin (p<0.001) and globulin (p<0.001) was observed after the race. Increases were seen in creatine kinase (p<0.001), creatinine (p<0.001), blood urea nitrogen (p<0.001), uric acid (p<0.001) and glucose (p<0.001) as the result of the race.
  
  
  CONCLUSIONS
  These data suggest that the non-specific cyclo-oxygenase inhibitor, ibuprofen, does not alter serum electrolyte concentrations during ultradistance running. However, the stress of ultradistance running appears to be related to significant changes in certain serum markers.
authors.affiliation: Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, USA. dumkecl@appstate.edu
authors.forename: Charles L
authors.initials: CL
authors.lastname: Dumke
authors.forename: David C
authors.initials: DC
authors.lastname: Nieman
authors.forename: Kevin
authors.initials: K
authors.lastname: Oley
authors.forename: Robert H
authors.initials: RH
authors.lastname: Lind
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001774:Blood Chemical Analysis; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004573:Electrolytes / Q000097:blood*; D005260:Female; D006801:Humans; D007052:Ibuprofen / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D012307:Risk Factors; D012420:Running / Q000502:physiology*; D012680:Sensitivity and Specificity; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D004573:Electrolytes; D007052:Ibuprofen