Studies Link Bike Seats, Erectile Dysfunction

Aug. 25, 2005 -- Erectile dysfunction and bicycling are the topics of three new studies in The Journal of Sexual Medicine.

The studies show that when erectile dysfunction is related to bicycling, it's linked to pressure on the perineum (the area between the anus and scrotum where nerves and arteries pass). The pressure, which comes from sitting on a bicycle seat with a nose extension, restricts blood flow to the penis, write the researchers.

But many men who bicycle will never have that problem, according to an editorial in the journal.

Two of the studies were done at the Institute for Sexual Medicine at the urology department of Boston University's medical school. The third study came from researchers in Italy.

Problem Doesn't Affect All Male Cyclists

The Italian study compared two different bike saddle designs. One of the designs is new; it has a saddle with a downward sloping nose-like front and a central cutout that can limit perineal pressure, which the researchers describe as looking like "the beak of an eagle." It showed less compression of the perineum than the other saddle, which is more often used by professional cyclists, write the researchers. They included N. Piazza, MD, of Giovanni and Paul Hospital's urology department in Venice, Italy.

In a journal editorial, Steven Schrader, PhD, notes that numbness in the urogenital area was associated with bicycle saddles as early as the 1890s and has been described in medical literature for the last 20 years.

"There continue to be endless testimonials about 'miles of cycling' and 'erections of steel,'" writes editorialist Steven Schrader, PhD. He works in the Reproductive Health Assessment area of the National Institute for Occupational Safety.

"Some of the testimonials have even appeared on scientific electronic bulletin boards, along with remarks regarding the proliferation of bicycle riders in China without erectile problems. They sound similar to the cigarette smoker proclaiming that they have smoked a pack a day for years without lung cancer," Schrader continues.

"One would not expect that every bicyclist would suffer from erectile dysfunction, any more than one would expect every smoker would get lung cancer," writes Schrader.

Next Steps

"The next steps are quite clear," writes Schrader. He calls for more research based on "sound ergonomics and physiological principles and testing" to come up with ways to lower the risk of erectile dysfunction from bicycling.

None of the studies make recommendations about what seats riders should use or determine the amount of cycling that might cause the problem.

A proper-fitting bicycle can help prevent these injuries, especially if the saddle is too high; appropriate frame size, handlebar height, and seat position are all important. A rider may consider changing the angle of the seat, which should be angled parallel to the ground or slightly forward, to help alleviate pressure on the perineum. Wider seats or those designed with a central cutout also help reduce perineal pressure and can help redistribute weight.

A change in riding style may help. Standing on the pedals during long rides can prevent pressure and help re-establish blood flow.