Bagatell, Carrie J.Bremner, William J.2008-10-172008-10-171990-04Fertil Steril. 1990 Apr;53(4):688-92http://hdl.handle.net/1773/4295In 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.en-US5-alpha reductase inhibitorsgonadotropinstestosteronereifenstein's syndromeklinefelter's syndromespermatogenesisandrologymale contraceptioncolchicineFollicle Stimulating Hormone, bloodSperm CountSperm MotilityEstradiol, bloodHydrocortisone, analysisMaleHumansBiological AssayResearch Support, U.S. Gov't, Non-P.H.S.RadioimmunoassayReference ValuesRunningLuteinizing Hormone, bloodBody WeightComparative StudyBody CompositionResearch Support, Non-U.S. Gov'tTestosterone, bloodSex Hormone-Binding Globulin, analysisAdultSemen, analysisResearch Support, U.S. Gov't, P.H.S.Article