美国一项研究显示，每周骑自行车累计超过5小时可能对男性精子数量和质量产生负面影响。
2200名男性参与这项调查研究。他们每人提供了一份精液样本并陈述日常健康与运动状况。在排除营养水平、体重、血压、内裤款式等其他因素后，研究者得出结论，每周骑自行车时间累计超过5小时的男性相比其他男性，精子数量和精子活性都有所下降。
数据显示，在缺少锻炼的男性群体中，23%的人精子数量偏低；而每周骑车超过5个小时的“骑车男”群体中，这一数值升至31%。另外，40%的“骑车男”精子活性不足，同样高于不运动男性。
引导这项研究的美国波士顿大学副教授劳拉·怀斯说，阴囊受伤或阴囊部位升温或可解释骑车与精子健康度下降之间的关联。
此项研究还显示，相比少锻炼男性，经常锻炼以及高强度锻炼的男性在精子数量和精子活力上出现问题的几率要低。
怀斯向路透社记者解释研究目的时说，以前针对竞技运动员的研究显示自行车运动对泌尿系统和精液质量有影响，“但是在日常锻炼男性中，我们不确定是否能找到这种关联”。
不过，怀斯承认，接受调查的男性全部来自男科诊所，调查结果可能因此而不具备普遍性，最终结果仍需获得更多研究认证。（生物谷Bioon.com）
生物谷推荐原文出处：
Fertility and Sterility doi:10.1016/j.fertnstert.2010.11.006
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.
Key Words: Physical activity, bicycling, sperm motility, sperm count, male infertility, IVF
