Bike Riding and Your Sex Life

Irwin Goldstein, MD

Dr. Goldstein presented the educational lecture to a small but focussed group of people for this sexual medicine information session. The following is a synopsis of his lecture.

Perineal anatomy/sexual physiology

Risk factors for erectile dysfunction include diabetes, obesity, high blood pressure and high cholesterol, all of which can lead to endothelial dysfunction. The endothelium lines all blood vessels. Injury to the endothelium affects blood flow. Conditions that can cause erectile dysfunction are the same as those which can cause endothelial dysfunction.

Endothelial injury can be random or focal. Random injury denudes the endothelium allowing cholesterol to get into the walls of blood vessels causing hardening of the arteries. Focal injury is non-denuded; it is atherosclerosis to a specific spot. Where arteries pass next to a bone, they are susceptible to focal injury of the endothelium. Arteries to the penis and clitoris pass through Alcock’s canal with one wall being bone.

When sitt on a chair you sit on your ischial tuberosities, your sit bones. The ischial pubic ramos connects the ischial tuberosities to the pubic bone. The internal portion of the clitoris and penis are attached to the ischial pubic ramos to give those organs structural support. When you straddle a narrow saddle, you don’t bear your weight on your ischial tuberosities like on a chair but on your ischial pubic ramos. The nerves and blood vessels running in Alcock’s canal are compressed against the bone. Straddling a traditional bike saddle x-rays show that all blood flow stops.

Sexual dysfunction is comprised of disorders of desire, arousal, orgasm and pain. Looking strictly at the biological aspect, arousal is affected by neural, vascular, endocrine and structural conditions. The bike seat affects both the neural and vascular conditions.

Review of study data

Pressure is measured by weight divided by surface area. The larger the bike seat, the less pressure per square inch. When biking faster, such as in the aero position, the rider sits forward putting more pressure on the nose. This pressure is greater than blood can flow into the area, stopping blood flow to the penis or clitoris. When using a noseless seat blood flow remains normal.

Young, otherwise healthy riders get focal endothelial dysfunction causing erectile dysfunction. Chronic injury causes non-denuding endothelial injury leading to atherosclerosis, whereas crush injury causes denuding endothelial injury leading to atherosclerosis of a particular focussed area. Smashing the area leads to bleeding into the inside part of the penis, subsequent erectile tissue fibrosis, leading to leakage out of the back of the penis so an erection can be achieved but doesn’t stay. Blunt perineal trauma is not just from bike riding. Primary impotence can be from blunt trauma in childhood, so that growing up a boy never gets erections.


The NIOSH (National Institute for Occupational Safety and Health) study examined night time erections of police officers, comparing erections of officers riding on bikes compared to those riding in cars. Bike riders had less night time erections than those in police cars.

The population study MMAS (Massachusetts Male Aging Study) showed that 3 hours or more of bike riding increased the risk of erectile dysfunction 1.72 times more than the general population.


Increasing the surface area of the seat helps decrease pressure. A two cheek noseless seat has more surface area than a traditional narrow saddle. An ultrasound of this seat shows unchanged blood flow, whereas there is no blood flow using a narrow saddle with or without a cutout in the center.

For bike racers who cannot ride on a noseless seat, it is also possible to adjust the angle of the hoods up and shorten the bike frame which puts more pressure on your hands, and tilt the seat down all of which puts less pressure on your crotch. The problem with this, however, is that increased pressure on the hands could injure the hands. For more information on adjusting your bike for a safer ride, click here.


Treatments include Viagra, vacuum devices, MUSE, penile injection, and penile revascularization surgery, where a healthy artery is attached to the penis to restore blood flow. This surgery is successful 70% of the time if the procedure is performed by surgeons who do this surgery routinely.


Do not minimize the importance of sexual function in your life. The adverse relationship between bike riding and sexual function will not go away.

Primary teaching affiliate
of BU School of Medicine