As a Urologist specializing in sexual medicine, I chuckle every time I watch the Tour de France. These amazing athletes with superhuman cardiovascular systems race up mountains to get the Maillot Jaune, otherwise known as the Yellow Jersey. They receive this winner’s jersey on a podium flanked by two attractive French beauties. The funny secret is that the winner likely can no longer feel his genitalia and would be useless to these Femme Fatales. Let’s find out why.
Humans were designed to sit on their ischial tuberosities, also known as ‘the sit bones.’ The ischial tuberosities are padded by muscle and fat and have no nerves, arteries, or other important structures close by. The area of the sit bones has a good blood supply so that humans can sit comfortably for long periods.
Most bike seats are too narrow to reach the sit bones. Instead of supporting their body weight on the sit bones, cyclists wind up putting their body weight on the ischiopubic rami, the connecting bones that join the ischial tuberosities together in the midline. Unlike the ischial tuberosity which is empty of critical structures, the ischiopubic ramus is close to penile erectile tissue, nerves, arteries, and the urethra. When a bicycle rider is in a tucked position strenuously cycling with toe clips , most of his weight is focused directly on the area where the nerves and arteries enter the penis. Straddling the bike seat compresses the arteries and nerves against the ischiopubic ramus. If this is done on a long ride, the cyclist frequently complains of numbness in the penis and scrotum.
Compressing arteries and nerves over hundreds of hours over many years can create pinpoint atherosclerotic changes which result in narrow blood vessels supplying the penis which lead to erectile dysfunction in these otherwise healthy men. Urologist Irwin Goldstein, who has done most of the basic research in this field, determined that only 11% of a person's body weight will compress the artery to the penis. When a man sits on a bicycle seat he is putting his entire body weight on the artery that supplies the penis. Goldstein measured a 66% average reduction in blood flow through the penile artery when men ride skinny saddles, 25% when riding a wide saddle, and no change when seated on a chair. 50% of the penis is actually inside the body.
Another way men cycling can cause erectile dysfunction is traumatic straddle injuries. Goldstein calculated that a 150-pound man pedaling at 20 mg could fall onto a top tube located 3 inches below the crotch with a force equal to a quarter of a ton. Younger boys can also cause damage by slipping and falling on the straddle bar or the horn of a narrow saddle. This can crush the penile artery and initiate the process that results in the narrowing of these arteries resulting in erectile dysfunction.
Fortunately, all cycling is not bad. It is an excellent form of cardiovascular exercise and is beneficial to erectile function in moderation. Analysis of data from the Massachusetts male aging study showed that individuals who cycle at least 3 hours/week have double the risk of developing erectile dysfunction and men who cycle less than 3 hours a week have half the risk of developing erectile dysfunction.
In order to bicycle safely, these are my recommendations:
1. Penile numbness and shrinkage are indicating that you are writing too much and if you want to avoid erectile dysfunction, you need to make adjustments.
- Purchase a bike seat that is at least as wide as the distance between your sit bones so that you sit on your ischial tuberosities rather than your ischio pubic ramus.
- The beak of the seat should be short and dropped down.
- When you are riding a stationary bike, there is no need for the beak of the seat because you are not steering the bike. You are better off with a seat without a beak.
- Make sure that your seat is padded
- Make sure that your seat is level or pointing downward
Tips for riding:
- Make sure that your legs are not fully extended at the bottom of the pedal stroke. Your knee should be slightly bent to support more of your weight.
- Be careful when using aero bars which encourage riding on the nose of the saddle.
- Stand up every 10 minutes to temporarily improve blood flow
- When you straddle your bike, make sure the top tube is 3 to 4 inches below your crotch
- When riding on rough terrain, get out of the saddle and use your legs as shock absorbers.
- Consider a recumbent bike in the gym. There is little chance of compression.
The next time you go out on a long training ride, consider if the glory and the cost of being on the podium. Even if you get there, you probably won’t get the girl, unless you heed my advice.