title: Changes in free radical generation and antioxidant capacity during ultramarathon foot race.
abstract: BACKGROUND
  Exhaustive exercise has been implicated in the generation of reactive oxygen species, resulting in oxidative stress. We studied the effect of a long-distance, endurance exercise on oxidative stress parameters in athletes who participated in the ultramarathon race Spartathlon (246 km).
  
  
  METHODS
  This study included 18 runners (16 men and 2 women) aged 42.8 +/- 1.4 years. Blood samples were obtained 24 h before (prerace), at the end (postrace) and 48 h after the end of the race (48 h postrace). We measured oxidative stress indices, including red cell glutathione, malonyldialdehyde and 8-iso-prostaglandin F(2a), as well as the total antioxidant capacity.
  
  
  RESULTS
  8-Iso-prostaglandin F(2a) level increased significantly at the end of the race, compared to prerace levels (up to 914.7 +/- 61.4 pg mL(-1) from 197.6 +/- 8.4 pg mL(-1)), and remained 2.5-fold increased over the baseline 48 h after the race (532.0 +/- 54.2 pg mL(-1), P < 0.000). The total antioxidant capacity of the athletes increased from a baseline of 289.6 +/- 9.0 micromol L(-1) to 358.7 +/- 11.0 micromol L(-1) immediately after the race and remained elevated 48 h later (350.6 +/- 7.6 micromol L(-1)) (P < 0.001).
  
  
  CONCLUSIONS
  Prolonged exercise induces a marked response of oxidative stress biomarkers, which in part is compensated by serum ability to scavenge free radicals. Whether these changes have long-term negative effects in the organism needs further investigation.
authors.affiliation: Laboratory of Nutrition and Clinical Dietetics, Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
authors.forename: K P
authors.initials: KP
authors.lastname: Skenderi
authors.forename: M
authors.initials: M
authors.lastname: Tsironi
authors.forename: C
authors.initials: C
authors.lastname: Lazaropoulou
authors.forename: C A
authors.initials: CA
authors.lastname: Anastasiou
authors.forename: A-L
authors.initials: AL
authors.lastname: Matalas
authors.forename: I
authors.initials: I
authors.lastname: Kanavaki
authors.forename: M
authors.initials: M
authors.lastname: Thalmann
authors.forename: E
authors.initials: E
authors.lastname: Goussetis
authors.forename: I
authors.initials: I
authors.lastname: Papassotiriou
authors.forename: G P
authors.initials: GP
authors.lastname: Chrousos
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D005609:Free Radicals / Q000097:blood*; D005978:Glutathione / Q000097:blood*; D006801:Humans; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*
chemical_list: D000975:Antioxidants; D005609:Free Radicals; C075750:8-epi-prostaglandin F2alpha; D008315:Malondialdehyde; D015237:Dinoprost; D005978:Glutathione