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.