title: Prospective study of hormonal and semen profiles in marathon runners.
abstract: OBJECTIVE
  To investigate the effect of marathon training on hormonal and semen profiles in male athletes.
  
  
  METHODS
  Prospective longitudinal study over 1 year.
  
  
  METHODS
  Department of Obstetrics and Gynaecology, University of Cape Town, South Africa.
  
  
  METHODS
  Twenty-four healthy male marathon runners, 25 to 54 years of age.
  
  
  METHODS
  Hormonal evaluation included determination of plasma concentrations of total T, LH, FSH, PRL, E2, and P. Semen analyses included an evaluation of count, motility, morphology, and volume. These profiles were correlated with training intensity.
  
  
  RESULTS
  The intensity of training increased significantly in the first 5 months of the study. This was accompanied by a significant rise in serum PRL levels and a fall in P levels. No other significant hormonal changes were identified. The semen volume and sperm motility and morphology fell significantly during training, but there was no significant alteration in the sperm count.
  
  
  CONCLUSIONS
  This longitudinal study demonstrates that endurance training can modify significantly hormonal profiles and semen parameters in long-distance runners.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Cape Town, Groote Schuur Hospital, South Africa.
authors.forename: C E
authors.initials: CE
authors.lastname: Jensen
authors.forename: K
authors.initials: K
authors.lastname: Wiswedel
authors.forename: J
authors.initials: J
authors.lastname: McLoughlin
authors.forename: Z
authors.initials: Z
authors.lastname: van der Spuy
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D004958:Estradiol / Q000097:blood; D005640:Follicle Stimulating Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood; D011446:Prospective Studies; D012420:Running / Q000502:physiology*; D012661:Semen / Q000166:cytology* / Q000502:physiology; D013076:Sperm Count; D013081:Sperm Motility; D013739:Testosterone / Q000097:blood
chemical_list: D006728:Hormones; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone