Physical activity and semen quality among men attending an infertility clinic

Objective: To examine the association between regular physical activity and semen quality. Design: Prospective cohort study. Setting: Couples attending one of three IVF clinics in the greater Boston area during 1993-2003. At study entry, male participants completed a questionnaire about their general health, medical history, and physical activity. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived using generalized estimating equations models, accounting for potential confounders and multiple samples per man. Patient(s): A total of 2,261 men contributing 4,565 fresh semen samples were enrolled before undergoing their first IVF cycles. Intervention(s): None. Main Outcome Measure(s): Semen volume, sperm concentration, sperm motility, sperm morphology, and total motile sperm (TMS). Result(s): Overall, none of the semen parameters were materially associated with regular exercise. Compared with no regular exercise, bicycling >= 5 h/wk was associated with low sperm concentration (OR 1.92, 95% CI 1.03-3.56) and low TMS (OR 2.05, 95% CI 1.19-3.56). These associations did not vary appreciably by age, body mass index, or history of male factor infertility. Conclusion(s): Although the present study suggests no overall association between regular physical activity and semen quality, bicycling >= 5 h/wk was associated with lower sperm concentration and TMS. (Fertil Steril (R) 2011;95:1025-30. (C) 2011 by American Society for Reproductive Medicine.)