title: Hormone levels of world class cyclists during the Tour of Spain stage race.
abstract: OBJECTIVE
  To evaluate the hormonal response to strenuous endurance exercise performed by elite athletes.
  
  
  METHODS
  Nine professional cyclists (mean (SD) age 28 (1) years; mean (SD) VO(2)MAX 75.3 (2.3) ml/kg/min) who participated in a three week tour race (Vuelta a España 1999) were selected as subjects. Morning urinary levels of 6-sulphatoxymelatonin (aMT6s) and morning serum levels of testosterone, follicle stimulating (FSH), luteinising hormone (LH), and cortisol were measured in each subject at t(0) (before the competition), t(1) (end of first week), t(2) (end of second week), and t(3) (end of third week). Urine samples of aMT6s were also evaluated in the evening at t(0), t(1), t(2), and t(3).
  
  
  RESULTS
  Mean urinary aMT6s levels had increased significantly (p<0.01) during the day after each stage (1091 (33) v 683 (68) ng/ml at t(1); 955 (19) v 473 (53) ng/ml at t(2); 647 (61) v 337 (47) ng/ml at t(3)). Both morning and evening aMT6s levels decreased significantly during the study. A similar pattern was observed for morning serum levels of cortisol and testosterone.
  
  
  CONCLUSIONS
  The results suggest that the basal activity of the pineal gland, adrenal glands, and testis may be decreased after consecutive days of intense, long term exercise.
authors.affiliation: Departamento de Ciencias Morfológicas y Fisiología, Universidad Europea de Madrid, Spain. alejandro.lucia@mrfs.cisa.uem.es
authors.forename: A
authors.initials: A
authors.lastname: Lucía
authors.forename: B
authors.initials: B
authors.lastname: Díaz
authors.forename: J
authors.initials: J
authors.lastname: Hoyos
authors.forename: C
authors.initials: C
authors.lastname: Fernández
authors.forename: G
authors.initials: G
authors.lastname: Villa
authors.forename: F
authors.initials: F
authors.lastname: Bandrés
authors.forename: J L
authors.initials: JL
authors.lastname: Chicharro
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001835:Body Weight; D002940:Circadian Rhythm; D015444:Exercise / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008550:Melatonin / Q000652:urine; D010807:Physical Endurance / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: D006728:Hormones; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D008550:Melatonin; D006854:Hydrocortisone