title: Early changes of the anemia phenomenon in male 100-km ultramarathoners.
abstract: BACKGROUND
  Sports anemia is a widely observed phenomenon after prolonged running. There are various factors that contribute to sports anemia, including hemodilution, exercise-induced oxidative stress, iron deficiency, gastrointestinal bleeding, hematuria, and hemolysis resulting from foot-strike and/or from compression of contracting muscles on capillaries. Until now, there has been no published report that describes the overall hematological, urinary, and fecal consequences in Asian male ultramarathoners after a 100-km (62.5-mile) ultramarathon event.
  
  
  METHODS
  A total of 25 male runners were recruited into our study. Blood was drawn 1 week before, immediately after, and then 24 hours subsequent to the race. Hematological samples were analyzed for the anemia phenomenon. Additionally, urinary and fecal samples were collected before and after the race for detection of occult blood.
  
  
  RESULTS
  The blood hemoglobin and erythropoietin values of the recruited runners showed a statistically significant rise in the immediate post-race values and a rapid drop in values at 24 hours post-race. Blood concentrations of red blood cells and hematocrit were significantly lower at 24 hours post-race compared with pre-race. The white blood cell count, interleukin-6, tumor necrosis factor-alpha, high-sensitivity C-reactive protein, and ferritin all showed significant increases both immediately after and 24 hours post-race compared with pre-race hematological values. There were immediate decreases of both haptoglobin and iron, as well as an increase of total iron-binding capacity levels in post-race blood tests. For both urinary and fecal samples, there was a statistically significant difference between the pre- and post-race results in occult blood.
  
  
  CONCLUSIONS
  Running a 100-km ultramarathon will induce substantial sports anemia, and oxidative stress response, hemolysis, hematuria, and gastrointestinal bleeding are typical factors that contribute to its onset.
authors.affiliation: Department of Emergency Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, ROC; Department of Emergency Medicine, Mackay Memorial Hospital, Taipei, Taiwan, ROC; Institute of Environmental and Occupational Health Sciences, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Chiu
authors.affiliation: National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Jiun-I
authors.initials: JI
authors.lastname: Lai
authors.affiliation: Department of Emergency Medicine, National Yang-Ming University Hospital, Yilan, Taiwan, ROC; Taiwan Wilderness Medical Association, Taipei, Taiwan, ROC.
authors.forename: Shih-Hao
authors.initials: SH
authors.lastname: Wang
authors.affiliation: Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC.
authors.forename: Chorng-Kuang
authors.initials: CK
authors.lastname: How
authors.affiliation: Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Li
authors.affiliation: Institute of Environmental and Occupational Health Sciences, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC; Department of Emergency and Critical Care Medicine, Taipei Medical University Hospital, Taipei, Taiwan, ROC; Department of Emergency Medicine, Taipei Medical University, Taipei, Taiwan, ROC. Electronic address: wfkao100a@hotmail.com.tw.
authors.forename: Wei-Fong
authors.initials: WF
authors.lastname: Kao
authors.affiliation: Institute of Environmental and Occupational Health Sciences, National Yang-Ming University School of Medicine, Taipei, Taiwan, ROC; Division of Clinical Toxicology and Occupational Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Chen-Chang
authors.initials: CC
authors.lastname: Yang
authors.affiliation: Department of Emergency Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, ROC.
authors.forename: Ray-Jade
authors.initials: RJ
authors.lastname: Chen
mesh_terms: D000740:Anemia / Q000209:etiology*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D012420:Running
chemical_list: D006454:Hemoglobins
keywords: clinical sports medicine; exercise-induced hemolysis; oxidative stress response; sports anemia; ultramarathon