title: Sperm counts and reproductive hormones in male marathoners and lean controls.
abstract: In women, chronic and intense endurance exercise is frequently associated with menstrual cycle alterations. In men, the effects of similar amounts of exercise are less well-studied. We tested the hypothesis that endurance exercise in men is also associated with alterations in reproductive function. We studied 12 marathon runners and 12 age-matched, lean controls; serum and semen samples were collected every 2 weeks for 12 weeks. Sperm counts, sperm morphologies, and mean levels of testosterone (T), free T, sex hormone binding globulin, cortisol, follicle-stimulating hormone, and biologically active luteinizing hormone (LH) were similar in the two groups. Mean levels of immunologically active LH were somewhat higher in the marathoners. We conclude that this level of strenuous, long-term endurance exercise does not have major adverse effects on reproductive function in men.
authors.affiliation: Department of Medicine and Population Center for Research in Reproduction, University of Washington, Seattle.
authors.forename: C J
authors.initials: CJ
authors.lastname: Bagatell
authors.forename: W J
authors.initials: WJ
authors.lastname: Bremner
mesh_terms: D000328:Adult; D001681:Biological Assay; D001823:Body Composition; D001835:Body Weight; D004958:Estradiol / Q000097:blood*; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D011863:Radioimmunoassay; D012016:Reference Values; D012420:Running; D012661:Semen / Q000032:analysis; D012738:Sex Hormone-Binding Globulin / Q000032:analysis*; D013076:Sperm Count; D013081:Sperm Motility; D013739:Testosterone / Q000097:blood*
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D006854:Hydrocortisone