Extreme mountain biking linked to lower sperm count. (May also Compromise Sperm Motility).

CHICAGO -- Compared with noncyclists, roughly 90% of mountain bikers who logged 3,000 miles or more a year had lower sperm count, decreased sperm motility, and scrotal abnormalities, Dr. Ferdinand Frauscher said at the annual meeting of the Radiological Society of North America.

To prevent possible loss of fertility, male mountain bikers should invest in bicycles with shock absorbers and better suspension features, which could double the cost of a mountain bike but potentially protect bodily functions influencing fertility, said Dr. Frauscher, head of the department of uroradiology at University Hospital, Innsbruck, Austria.

He reported on a study that compared 35 noncyclists with 40 extreme mountain bikers, who rode more than 2 hours a day, 6 days a week for more than 3,000 miles a year. Ages ranged from 18 to 44 years for the extreme cyclists and 17 to 41 for the noncyclists.

Ultrasonography, using a 12-MHz transducer, showed scrotal abnormalities in 35 bikers (88%) and 9 nonbikers (26%).

Abnormalities in the biking group included 25 scrotal calculi, 22 epididymal cysts, 14 epididymal calcifications, 13 testicular calcifications, 6 varicoceles, 5 hydroceles, and 3 testicular microlithiases. In noncyclists there were six epididymal cysts, two testicular calcifications, and three varicoceles. A total of 21 bikers (52%) reported a history of intermittent scrotal pain, compared with 7 noncyclists (20%).