Objective   To investigate the relationship between semen quality and sedentary time.

  Methods   A cross-sectional survey was conducted among 4 532 men (aged 18 – 60 years) seeking fertility consultation at a reproductive center of a hospital in Shenzhen city from March 2017 through May 2019. Questionnaire interview and semen sampling were carried out among the participants. Routine indicators of semen quality were determined with a computer assisted semen analysis system (CASA) and the relationship between sedentary time and semen quality indicators was assessed with binary logistic regression analysis.

  Results  In comparison to those in the participants reporting the sedentary time of less than 4 hours per day, significantly lower sperm progressive motility rate (53.18 ± 19.59% vs. 55.29±19.15%, F = 2.96; P < 0.05) and total sperm motility rate (64.30 ± 20.16% vs. 66.57 ± 19.50%, F = 3.19; P < 0.05) were detected in the men reporting the sedentary time of 8 hours and above per day. The results of logistic regression analysis showed that compared to those with the sedentary time of less than 4 hours per day, the participants with the sedentary time of 8 hours and above per day were at a significantly increased risk of having a reduced sperm progressive motility (odds ratio = 1.29, 95% confidence interval: 1.03 – 1.62) after adjusting for age, body mass index, days of abstinence, smoking, alcohol drinking, and time of physical activity.

  Conclusion  Prolonged sedentary time (≥ 8 h/day) is a risk factor for decreased sperm progressive motility in adult men.