title: Absence of blood oxidative stress in trained men after strenuous exercise.
abstract: Exercise has been noted in some, but not all, studies to elicit an oxidative stress. The discrepancy in findings may be related to differences in exercise intensity across protocols, as well as to differences in training status of participants.
  
  
  OBJECTIVE
  We compared blood oxidative stress biomarkers in exercise-trained men after three different bouts of exercise of varying intensity and duration, as well as a nonexercise condition.
  
  
  METHODS
  On different days, men (n = 12, 21-35 yr) performed aerobic cycle exercise (60 min at 70% HR reserve) and cycle sprints (five 60-s sprints at 100% maximum wattage obtained during graded exercise testing and ten 15-s sprints at 200% maximum wattage obtained during graded exercise testing). Blood was collected before and 0, 30, and 60 min after exercise and analyzed for malondialdehyde, hydrogen peroxide (H(2)O(2)), advanced oxidation protein products, and nitrate/nitrite (NO(x)). As indicators of antioxidant status, Trolox equivalent antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase were measured.
  
  
  RESULTS
  No differences were noted in malondialdehyde, H(2)O(2), advanced oxidation protein product, or NO(x) between conditions or across time (P > 0.05). Antioxidant capacity was generally highest at 30 and 60 min after exercise and lowest at 0 min after exercise.
  
  
  CONCLUSIONS
  In trained men, and considering the limitations of the current design (e.g., inclusion of selected oxidative stress and antioxidant biomarkers measured in blood only), strenuous bouts of exercise do not result in a significant increase in blood oxidative stress during the 1-h postexercise period. These findings may be related to attenuation in reactive oxygen species production as an adaptation to chronic exercise training and/or a protective effect of the antioxidant system in response to acute strenuous exercise.
authors.affiliation: Cardiorespiratory/Metabolic Laboratory, The University of Memphis, Memphis, TN 38152, USA.
authors.forename: Tyler M
authors.initials: TM
authors.lastname: Farney
authors.forename: Cameron G
authors.initials: CG
authors.lastname: McCarthy
authors.forename: Robert E
authors.initials: RE
authors.lastname: Canale
authors.forename: Brian K
authors.initials: BK
authors.lastname: Schilling
authors.forename: Paul N
authors.initials: PN
authors.lastname: Whitehead
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bloomer
mesh_terms: D000328:Adult; D062107:Advanced Oxidation Protein Products / Q000097:blood; D000975:Antioxidants / Q000032:analysis; D015415:Biomarkers / Q000097:blood; D001769:Blood / Q000378:metabolism*; D002374:Catalase / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D006861:Hydrogen Peroxide / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D018384:Oxidative Stress / Q000502:physiology*; D013482:Superoxide Dismutase / Q000097:blood; D055815:Young Adult
chemical_list: D062107:Advanced Oxidation Protein Products; D000975:Antioxidants; D015415:Biomarkers; D009566:Nitrates; D009573:Nitrites; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase