title: Plasma oxytocin during intense exercise in professional cyclists.
abstract: OBJECTIVE
  This study was designed to explore the plasma oxytocin (OT) response to exercise until exhaustion in trained male cyclists.
  
  
  METHODS
  Twelve professional cyclists (EXP group; age: 26 +/- 2 years; VO(2)max: 4,804 +/- 549 ml) and 10 sedentary young men (CONT group; age: 23 +/- 2 years; VO(2)max: 3,146 +/- 602 ml) performed a maximal incremental exercise test on a cycle ergometer. Evaluation was made of the oxygen uptake (VO(2)) and concentrations of blood lactate and plasma OT immediately before, during and immediately after the tests, respectively.
  
  
  RESULTS
  Significant increases (p < 0.01) related to exercise were recorded in VO(2) and lactate concentration within each group, while no such changes were observed in OT levels. OT values, on the other hand, were significantly lower (p < 0.01) in EXP than in CONT throughout the tests.
  
  
  CONCLUSIONS
  It was concluded that plasma OT shows no response to graded exercise until exhaustion in professional cyclists.
authors.affiliation: Departamento de Enfermería, Universidad Complutense de Madrid, E-28040 Madrid, Spain. jlchicharro@enf.ucm.es
authors.forename: J L
authors.initials: JL
authors.lastname: Chicharro
authors.forename: J
authors.initials: J
authors.lastname: Hoyos
authors.forename: F
authors.initials: F
authors.lastname: Bandrés
authors.forename: F
authors.initials: F
authors.lastname: Gómez Gallego
authors.forename: M
authors.initials: M
authors.lastname: Pérez
authors.forename: A
authors.initials: A
authors.lastname: Lucía
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000503:physiopathology; D006801:Humans; D008297:Male; D010121:Oxytocin / Q000097:blood*
chemical_list: D010121:Oxytocin