title: Comparison of platelet function between sedentary individuals and competitive athletes at rest.
abstract: BACKGROUND
  There are controversial evidences on the effect of different types and workloads of physical exercise on primary hemostasis. In particular, little is known on the chronic influence of a strenuous and regular aerobic training regimen on platelet function.
  
  
  METHODS
  The aim of this investigation was to compare platelet function between sedentary controls and trained athletes at rest and to evaluate whether a greater amount of exercise performed in professional cyclists may contribute to increased platelet chronic responsiveness compared to both elite cyclists and sedentary individuals. Platelet's ability to adhere and aggregate was assayed following a 12-24 h resting period in 49 active professional male road cyclists, 40 elite male cyclists and 43 matched sedentary healthy male volunteers, by the platelet function analyzer 100 (PFA-100).
  
  
  CONCLUSIONS
  Mean values of the collagen-epinephrine test did not differ between controls and athletes (sedentary controls: 111 +/- 33 s; elite athletes: 113 +/- 26 s, p = 0.93; professional athletes: 120 +/- 33 s; p = 0.33), whereas mean values of the collagen-ADP test displayed a slightly but significant trend towards decreased values when comparing sedentary controls (83 +/- 21 s) with either elite (77 +/- 11 s, p < 0.01) or professional (75 +/- 16 s, p < 0.01) athletes.
  
  
  CONCLUSIONS
  The trend towards slightly lower collagen-ADP values are suggestive for a modest but significant chronic activation of primary hemostasis, highlighting the need to set appropriate reference ranges for the PFA-100 when evaluating primary hemostasis in physically active subjects.
authors.affiliation: Sezione di Chimica e Microscopia Clinica, Università degli Studi di Verona, Verona, Italy. ulippi@tin.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Martina
authors.initials: M
authors.lastname: Montagnana
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Salvagno
authors.forename: Massimo
authors.initials: M
authors.lastname: Franchini
authors.forename: Gian Cesare
authors.initials: GC
authors.lastname: Guidi