It has long been thought that mountain biking enthusiasts are at a greater risk of becoming impotent.

The new research, by a team of Austrian scientists, suggests they could also be risking a range of problems with their scrotums, including benign tumors, cysts, infection and swelling.
The problem appears to be the jarring and vibrating associated with riding a mountain bike over rough landscapes. Study author Ferdinand Frauscher, from the department of Uroradiology at University Hospital, Innsbruck, said: "Bike seats with holes in them, or shaped like a 'Y' to alleviate the pressure, may help somewhat, as might wearing a jock-strap or other support.
But we think full-suspension bikes with shock systems, or those with shock absorbers in the seat are probably more beneficial in this case, because the bike rather than the body absorbs the shock." Dr Frauscher's team found that in a comparison of scrotal ultrasounds, 96% of the heavy-duty bikers showed irregularities compared to just 16% of the non-bikers.

Common problems. The most common problems among riders, who averaged more than 12 hours a week in the saddle, were: Benign tumors (84%) Sperm-containing cysts (49%) Calcium deposition in the sperm tube (epididymis), which can cause swelling and infection (44%) Fluid cysts (38%) Twisted veins (nine percent).
In contrast, only five of the non-bikers had sperm-containing cysts - a problem which becomes increasingly common with age. Only half of the cyclists actually complained of pain. However, this did not mean that, in some cases, they did not require treatment. Dr Frauscher said a course of antibiotics would take care of any infections, but a needle biopsy or surgery might be required to rule out cancer or to alleviate pain.

He said the fit of the seat was critical for warding off problems, but padded shorts could help.
Good shock absorbers, good suspension, and frequent rests could also take the pressure off the scrota.
Mr. Derek Machin, clinical director of urology at University Hospital, Aintree, said: "This is an interesting finding and might shed some light on the reasons why people get scrotal swellings. It might be due to mild trauma, multiply repeated." Mr. Machin said most scrotal swellings did not require medical intervention unless they became tender or embarrassing.
The research was presented to a meeting of the Radiological Society of North America.