Paternal physical and sedentary activities in relation to semen quality and reproductive outcomes among couples from a fertility center

Is paternal physical activity associated with semen quality parameters and with outcomes of infertility treatment? Among men presenting for infertility treatment, weightlifting and outdoor activities were associated with higher sperm concentrations but not with greater reproductive success. Higher physical activity is related to better semen quality but no studies to date have investigated whether it predicts greater reproductive success. The Environment and Reproductive Health (EARTH) Study is an on-going prospective cohort study which enrolls subfertile couples presenting at Massachusetts General Hospital (2005-2013). In total, 231 men provided 433 semen samples and 163 couples underwent 421 IVF or intrauterine insemination cycles. Leisure time spent in physical and sedentary activities over the past year was self-reported using a validated questionnaire. We used mixed models to analyze the association of physical and sedentary activities with semen quality and with clinical pregnancy and live birth rates. Men in this cohort engaged in a median of 3.2 h/week of moderate-to-vigorous activities. Men in the highest quartile of moderate-to-vigorous activity had 43% (95% confidence interval (CI) 9, 87%) higher sperm concentrations than men in the lowest quartile (P-trend = 0.04). Men in the highest category of outdoor activity (a parts per thousand yen1.5 h/week) and weightlifting (a parts per thousand yen2 h/week) had 42% (95% CI 10, 84%) and 25% (95% CI -10, 74%) higher sperm concentrations, respectively, compared with men in the lowest category (0 h/week) (P-trend = 0.04 and 0.02). Conversely, men who reported bicycling a parts per thousand yen1.5 h/week had 34% (95% CI 4, 55%) lower sperm concentrations compared with men who reported no bicycling (P-trend = 0.05). Paternal physical and sedentary activities were not related to clinical pregnancy or live birth rates following infertility treatment. The generalizability of the findings on live birth rates to populations not undergoing infertility treatment is limited. Certain types of physical activity, specifically weightlifting and outdoor activities, may improve semen quality but may not lead to improved success of infertility treatments. Further research is needed in other non-clinical populations. The authors are supported by NIH grants R01-ES009718, ES000002, P30-DK046200, T32-DK007703-16 and ES022955 T32-HD060454. None of the authors has any conflicts of interest to declare.