Biking Threatens Male Fertility
by Ed Susman -
InternationalCHICAGO, Dec 02, 2002 (United Press
International via COMTEX) Mountain bicycle enthusiasts who assault the hills
with extreme competitiveness might be risking not only their sexual health but
also their chances of having children, researchers reported Monday.
Compared to non-cyclists, mountain bikers
register less than half the sperm count and less sperm movement, researchers
"We were surprised that the motility
(spontaneous movement) of the sperm and sperm count were reduced in the
mountain bikers and only the mountain bikers," said Dr. Ferdinand Frauscher,
head of the department of uroradiology at University Hospital, Innsbruck,
"Based on our findings, we believe that
extreme mountain biking results in semen alteration, which may have an impact
In Frauscher's study, ultrasound imaging of
the scrotums of 40 mountain bikers most of whom showed up at their
doctors' offices because they found suspicious lumps in their scrotums
found the cyclists had more tiny calcifications than did a group of similar men
who were not mountain bikers.
Nearly 90 percent of the cyclists 35
out of 40 demonstrated abnormalities in their scrotums compared with 26
percent 9 out of 35 of the non-cyclists. Mountain-biking men had
more cysts and blood vessel abnormalities than the non-mountain bikers.
The cyclists were included in the study if
they spent more than two hours a day on their bicycles and rode their mountain
bikes more than 3,000 miles a year.
Frauscher noted in North America more than
10 million people pursue the sport of mountain biking and that number continues
In the study, presented at the annual
meeting of the Radiological Society of North America, Frauscher said the sperm
counts of non-cyclists average about 47 million per milliliter, while the sperm
counts in mountain bikers was 20 million per milliter. About 51 percent of the
non-cyclists' sperm showed normal movement compared to 29 percent of the sperm
in the mountain bikers.
To demonstrate, Frauscher showed a film of
microscopic images that depicted scores of non-cyclists' sperm rapidly moving
across the slide. In contract, the film of mountain-bikers' sperm showed a lone
sperm inching across the frame.
"This may be the first study to show a
well-document correlation between scrotal injury and decrease sperm counts and
motility," said Dr. Barry Goldberg, professor of radiology at Thomas Jefferson
University in Philadelphia.
"Certainly it is the only case I have seen
in the radiological literature. We do know that lower sperm counts and sperm
motility reduce the ability to conceive," he added.
"The exact causes for the decreased sperm
motility are unclear," Frauscher said. "We believe that repeated mechanical
trauma to the testicles results in some degree of vascular damage, and may
thereby cause a reduction in sperm motility."
Frauscher reported his patients between age
20 and 30 tended to say they were not worried about their fertility, but were
concerned instead about the lumps they were feeling because testicular cancer
is the most frequent cancer among men of that age group.
None of the patients had cancer but a higher
percentage of the mountain bikers had hardened objects in the scrotum that
might be related to cancer development. Two of the patients had elevated cancer
markers in their blood, and underwent biopsy.
"Microtrauma that is caused by mountain
biking causes the body to go through its healing process," said Goldberg. "And
when there is healing going on there is always the chance that one of those
cells will inappropriately continue to grow, that is, become a cancer."
Frauscher suggested that patients who engage
in mountain biking should invest in more expensive and somewhat heavier
vehicles that include saddle and pedal suspension systems, use padded saddles
and padded pants. Goldberg concurred, saying these were reasonable attempts to
reduce the impact on the scrotum and to reduce injuries.
Frauscher added that three patients who were
approaching 40 did visit his office because of concerns about fertility. He and
colleagues are investigating whether using impact suspension equipment reduces
the risk to the cyclists' fertility. He said larger calcifications and larger
cysts could be surgically removed and surgery also could resolve other related