Biking may be hazardous to your erection

by Charles Downey

A 54-year-old Boston attorney figured he was in great shape because, weather permitting, he rode his bicycle at least one hundred miles a week. During inclement weather, he pedaled on a stationary bike.

But during a 200-mile, two-day charity event, the lawyer noticed his penis was numb, and that's not the worst of it. For about the next month, he had trouble getting, and keeping, an erection.

Puzzled, he made an appointment to see Irwin Goldstein, MD, professor of urology at Boston University School of Medicine. Dr. Goldstein, who sees about six avid cyclists a week suffering from erectile dysfunction (ED), quickly suspected the problem was caused by sitting too long on a narrow, hard bicycle saddle. And when an avid cyclist leans forward on his arms in the \"aero\" position, he puts even more pressure on a delicate part of his anatomy.

The human rear is perfectly designed to support the weight of the body on two \"sit bones.\" Those structures are protected by muscle and fat and have no arteries or nerves that could be crushed by your weight. As long as you are sitting on a flat surface, like a chair or couch, your sit bones easily support your weight.

It's a different story when you sit for long periods on a narrow bicycle seat. \"The penis is part of a hydraulic system,\" says Dr. Goldstein. \"When stimulated, its twin chambers fill with blood until it's erect. After ejaculation, the blood leaves and the penis softens again.\"

But about half that hydraulic system is inside the body. When a man sits on a narrow bicycle seat, his body weight can crush the pudendal artery and nerves that serve the penis. That sensitive area between the anus and the scrotum is known as the perineum. So bike riding can result in temporary and permanent impotence. Extra padding or jell padding in the seat does not help because the padding bunches up and also cuts off circulation.

\"I tell my biking patients they take their sex lives in their hands when they ride bicycles,\" says Dr. Goldstein.

Dr. Goldstein and his colleagues at Duke University in Durham, North Carolina and Case Western Reserve University in Cleveland, Ohio recently studied 81 avid bike riders who were suffering from ED. The team presented their findings in the December, 1999 Journal of Urology. The researchers found that nerves, arteries and veins in the perineum can indeed be damaged by bicycle seats.

Yet another test group of 100 men with ED revealed that it takes only about 11% of a man's body weight to compress the vital artery. Moreover, some cyclists have fallen on the bike's cross bar and injured the groin. The bike-related impotence problems vary: Some erections are not sustainable because although blood gets into the penis, damaged valves can't hold it there. Others may have trouble ejaculating due to decreased sensation. Overall, Dr. Goldstein estimates there are about 100,000 impotence-cursed men whose woes started with bicycling. Overweight riders and cyclists who peddle many miles weekly are at higher risk for impaired erection.

Of course, the picture isn't totally bleak. While Dr. Goldstein says the perfect seat would look like a toilet seat and would remove all pressure from delicate areas, some men have switched to recumbent bicycles in which the rider sits reclined and peddles with his legs stretched out in front. Others use wider saddles or switch to one of the half dozen seats that claim to be more guy-friendly. Some of those seats are hollow in the middle so the perineum is not crushed, and some are basically two large circles upon which the sit bones rest. Some have a large wedge or oval cutouts in the middle while still others have a long groove down the middle.

Ken Taylor, MD, and his colleagues from the University of California, San Diego, dissected and examined cadavers to discover exactly why and how a hard bicycle seat can cause ED, groin and penile numbness and urinary tract infections in some riders.

The study, presented at the 1999 annual meeting of the American Society of Sports Medicine, estimated that between six and 21% of male cyclists have experienced genital numbness. The researchers know exactly how numb the genitals become because they tested those areas with a device known as an esthesiometer?a gadget used to measure the sensitivity, or lack thereof, in people with diabetes who often lose feeling in their hands and feet.

The researchers recruited 15 hard-core cyclists, most of whom pedal between 150 and 300 miles weekly. The cyclists rode on both a standard saddle and a new cutout design created and manufactured by Serfas, a bicycle parts firm in Lake Forest, California. Eighty percent of the study group complained of numbness after riding on a conventional saddle while only 14% encountered such problems while using the cutout design.

Also jumping into the saddle-sore relief business was Specialized Bicycle Components, Inc. of Morgan Hill, California. Medical designer Roger Minkow, MD, helped develop a new perineum-sparing seat, the Body Geometry Saddle. Supplying additional advice on the design were urologists and two police bicycle squads. Dr. Minkow specializes in ergonomic seating, from special chairs for plastic surgeons, who must endure long operations, to the seats now used by United Airlines pilots.

The narrow Specialized seat has a v-shaped wedge in the rear, right where a man's perineum would sit. For testing, the firm consulted with Robert Kessler, MD, professor of urology at Stanford University Medical Center in Palo Alto, California. Twenty-five cyclists who routinely suffered perineal pain, numbness and erectile dysfunction while biking rode on the new seat at least six hours weekly for a month.

\"Fourteen had complete relief, nine had almost complete relief, one had partial relief and one said there was no change,\" says Dr. Kessler.

Bicycle firms Diamondback and Avocet, Inc. also offer masculine-compatible seats. \"Not every bicycle rider develops erectile dysfunction, just as not every smoker develops lung cancer,\" says Dr. Taylor, who is also a consultant to Serfas. \"But a standard bicycle seat is a risk factor.\"