Preliminary study suggests frequent cycling could affect male fertility

Dec 13, 2010 by Lin Edwards report

(PhysOrg.com) -- A study of men attending fertility clinics has found bicycling for five or more hours a week was associated with low sperm count and poor sperm motility.

Previous studies of competitive cyclists has linked the sport to poor as well as urinary and genital problems, but until now no such links have been shown in non-competitive cyclists.

Dr. Lauren Wise, Associate Professor of Epidemiology at Boston University School of Public Health (BUSPH), decided to see if there was a relationship between and fertility. Along with her colleagues she studied 2,261 who were members of couples attending one of three fertility clinics in the Boston area between 1993 and 2003. She gave each of the men about to undergo their first IVF cycles a questionnaire that included questions about their exercise levels, type of exercise, general health and medical history, and each man also provided at least one semen sample.

The results of the prospective cohort study, published in the journal showed that, after adjustment for variables such as multivitamin use, blood pressure, weight, and type of underwear worn, exercise levels generally had no overall impact on sperm quality and quantity.

When the researchers broke the data down into specific forms of exercise, they found that men who bicycled for five hours or more a week were more likely to have a low sperm count and poor quality (low motility) sperm than men who did not exercise at all or those doing other forms of exercise. Less than a quarter of the non-exercisers had a low sperm count compared to 31 percent of the frequent bike riders. Just over a quarter (27 percent) of the sedentary men had poor sperm motility compared with 40 percent of the cyclists.

Dr. Wise speculated that semen may be affected by temperature increases in the scrotum or trauma while cycling, but said it was much too early to be sure of the cause, and she added that it is as yet “unknown whether itself actually caused the issues with their .” Since the men were attending fertility clinics, it is also not possible to say whether or not the findings would be the same among the general population, and further research would be needed to make any firm conclusions.

Explore further: Testosterone testing has increased in recent years

More information: Physical activity and semen quality among men attending an infertility clinic, Fertility and Sterility, doi:10.1016/j.fertnstert.2010.11.006

Related Stories

Male painters exposed to fertility damaging chemicals

May 23, 2008

Men working as painters and decorators who are exposed to glycol ethers are more likely to have poor semen quality, according to research carried out by scientists from the Universities of Sheffield and Manchester.

Synthetic cannabinoid may aid fertility in smokers

Dec 02, 2006

A reproductive medicine specialist at the University at Buffalo has shown that a new compound may improve the fertility of tobacco smokers who have low sperm count and low percentage sperm motility.

Researchers Develop Test to Identify 'Best' Sperm

May 20, 2010

(PhysOrg.com) -- Researchers at Yale School of Medicine have discovered a method to select sperm with the highest DNA integrity in a bid to improve male fertility. The method is comparable to that of the egg’s ...

Recommended for you

Testosterone testing has increased in recent years

58 minutes ago

(HealthDay)—There has been a recent increase in the rate of testosterone testing, with more testing seen in men with comorbidities associated with hypogonadism, according to research published online Nov. ...

AMA: Hospital staff should consider impact of CMS rule

10 hours ago

(HealthDay)—Hospital medical staff members need to consider the impact of a final rule issued by the Centers for Medicare & Medicaid Services (CMS) that revised the conditions of participation for hospitals ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

genastropsychicallst
2.3 / 5 (3) Dec 13, 2010
But when i'm walking i see much longer the womans.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.