title: Effect of cycling in the heat for 164 km on procoagulant and fibrinolytic parameters.
abstract: OBJECTIVE
  We assessed the impact of completing the Hotter'n Hell Hundred (HHH), an annual 164 km road cycling event performed in a hot environment, on hemostatic balance in men.
  
  
  METHODS
  Sixteen men who completed the ride in <6 h were included in this study. Plasma samples were collected on that morning of the ride (PRE) and immediately on the completion of the ride (IP). Primary hemostasis was assessed by platelet count and von Willebrand factor antigen (vWF:Ag). Coagulation was assessed by measuring prothrombin fragment 1 + 2 (PTF 1 + 2) and thrombin-antithrombin complex (TAT), whereas fibrinolysis was assessed by plasminogen activator inhibitor antigen (PAI-1 Ag), tissue plasminogen activator (tPA Ag), and D-Dimer analyses.
  
  
  RESULTS
  Compared to PRE, increases (p < 0.001) were observed at IP for platelets (39 %), vWF:Ag (65 %), PTF 1 + 2 (47 %), TAT (81 %), tPA Ag (231 %), PAI-1 Ag (148 %), and D-Dimer (54 %). PRE PAI-1 Ag concentrations were directly related to BMI and waist circumference (p < 0.05). D-Dimer concentrations at IP correlated positively with age (p < 0.05).
  
  
  CONCLUSIONS
  Completing the HHH activated the coagulation and fibrinolytic systems in balance. Age was positively correlated with IP D-Dimer concentrations. Additionally, participants displaying a larger BMI and waist circumference exhibited a positive correlation with PRE PAI-1 Ag concentrations.
authors.affiliation: Department of Military and Emergency Medicine, Uniformed Services University of Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA, brian.kupchak@gmail.com.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Kupchak
authors.forename: Amy L
authors.initials: AL
authors.lastname: McKenzie
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Luk
authors.forename: Cathy
authors.initials: C
authors.lastname: Saenz
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Kunces
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Ellis
authors.forename: Jakob L
authors.initials: JL
authors.lastname: Vingren
authors.forename: Elaine C
authors.initials: EC
authors.lastname: Lee
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Ballard
authors.forename: Evan C
authors.initials: EC
authors.lastname: Johnson
authors.forename: Stavros A
authors.initials: SA
authors.lastname: Kavouras
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Ganio
authors.forename: Jonathon E
authors.initials: JE
authors.lastname: Wingo
authors.forename: Keith H
authors.initials: KH
authors.lastname: Williamson
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Armstrong
mesh_terms: D000328:Adult; D000367:Age Factors; D000991:Antithrombins / Q000378:metabolism; D001642:Bicycling / Q000502:physiology*; D005342:Fibrinolysis; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D011516:Prothrombin / Q000378:metabolism; D013917:Thrombin / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D000991:Antithrombins; D017395:Plasminogen Activator Inhibitor 1; D014841:von Willebrand Factor; D011516:Prothrombin; D013917:Thrombin