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Dr. Irwin Goldstein says men should not ride bikes. His new study says why.

The Unseen Danger
by Joe Kita

When he talks about bicycles, Irwin Goldstein, M.D., uses the same tone that other physicians reserve for cigarettes.

"Men should never ride bicycles," he says matter-of-factly. "Riding should be banned and outlawed. It's the most irrational form of exercise I could ever bring to discussion."

In his office at Boston University Medical Center, Dr. Goldstein treats six men a week on average, whom, he says, have become impotent from riding a bicycle. Overall, this urologist estimates there are about 100,000 men who have lost the ability to get or maintain satisfactory erections because of penile damage inflicted by either the bike's top tube or its saddle.

This is the message Dr. Goldstein is vociferously delivering in media interviews, university lectures and medical seminars nationwide. Considered one of the country's leaders in impotency research, Dr. Goldstein helped engineer the shift

in treating male sexual dysfunction from a psychological problem to a chiefly physical one. No doubt, he is an outspoken revolutionary, but he is a revolutionary with credentials. Right now, armed with a new study, he's out to overthrow bicycling.

Last May, Bicycling exclusively obtained the results of Dr. Goldstein's new study on the effects of saddle pressure and compression on the penile artery. The data has yet to be published in a medical journal and as such, many of the details cannot be released for verification, discussion or attack. But the results were enough to convince us that what may at first seem like an outlandish claim (before this article was assigned we had yet to hear of a single instance of saddle-related impotence) deserves attention. And as we began to research this piece, we discovered the problem may be more prevalent than we initally believed. It was, in fact, a problem one of our own staff had been secretly battling (see "The Down Side of Cycling," page 72). We are not telling you not to ride your bike. In fact, with the exception of Dr. Goldstein, all the doctors we spoke with stated that the health benefits of cycling far outweigh what is still an unknown risk. Just listen up.

Dr. Goldstein first made headlines in the late '80s, by suggesting that bike manufacturers either eliminate the top tube (as with a traditional girls' design) or heavily pad it to protect boys and men who might land on it. Later studies of his, reported in the Journal of Urology, found that a 150-pound cyclist pedaling at 20 mph could fall onto a top tube located three inches below the crotch with a force equal to a quarter ton.

The majority of bicycle-related impotency cases Dr. Goldstein treats stem from this kind of accident. Take Kyle Cashman (the names of Goldstein's patients have been changed), for example. At age seven, he crashed his father's bike and slammed his crotch against the top tube. Other than the immediate pain, he felt no adverse effects until he reached puberty. Then he started experiencing erection problems that he lived with for almost a decade before seeking medical attention. An X-ray, like the ones shown here, enabled Dr. Goldstein to pinpoint where the artery that sends blood to the penis had been damaged.

Few have paid attention to Dr. Goldstein's warnings. In fact, within cycling circles he was shrugged off and regarded as somewhat of a kook. But as he developed a nationwide reputation, he began to see more impotent riders who couldn't point to any one accident as a potential cause. This eventually led him to explore the role saddle compression may play in cycling.

Richard Belmont, a 54-year-old attorney, never had any sexual-performance problems. But after cycling almost 200 miles during a two-day charity ride last summer, he suddenly became impotent. Pedaling a new road bike equipped with a racing saddle and an aero bar, he noticed that his penis was numb for most of the event. After experiencing erection difficulties during the next six months, he finally visited Dr. Goldstein, who spotted arterial damage at the base of the shaft.

Greg Jackson, a 33-year-old computer programmer, always kept himself in great shape. He swam, ran and bicycled. But after a long mountain bike ride on rough terrain, he experienced pain that went beyond the usual aches. Its epicenter was near his penis, which wouldn't get as hard or as erect as it used to. When he eventually consulted Dr. Goldstein, he learned that his main penile artery had become clogged.

Jim Broderman, 55, never had a bicycle accident or any sexual misfire. But after a heart attack, he started riding a stationary bicycle. Seven years later, after pedaling 50,000 miles, his heart was strong, but his penis had gone limp. X-rays uncovered no abnormalities in the penis itself, but right where it attaches to the pubic bone (exactly where the bicycle seat fits), Dr. Goldstein found arterial scarring that was hampering blood flow.

To understand what may have happened to these men (and, most important, how you can keep it from occurring in your neighborhood,) you need to know a few things about male anatomy. The penis is a hydraulic system. During sexual stimulation, its twin chambers fill with blood until it's firm and erect. After stimulation ends or there's ejaculation, the blood leaves and the penis softens again. The trigger for this increased blood flow is nerve impulses that originate in the brain and race down the spinal cord to the penis. All this happens very fast--typically three to five seconds from stimulation to erection in a young male.

All of this essential wiring (nerves, blood vessels) is funneled through an area called the perineum, which lies between the sit bones. To better understand what we're talking about, squat and sit on a low-lying step or curb. You'll feel your weight being supported by your pelvis, as evolution intended. But when you're riding a bicycle, Dr. Goldstein explains that your weight is being focused between these sit bones, and that's where the arteries and nerves that feed the penis are located. Since they're essentially unprotected, they're prone to damage from impacts and, he suggests, possibly even from chronic saddle pressure.

"Fifty percent of the penis is actually inside the body," explains Dr. Goldstein. "When a man sits on a bicycle seat he's putting his entire body weight on the artery that supplies the penis. It's a nightmarish situation."

To study how such pressure might compromise sexual performance, Dr. Goldstein set out to measure the degree of compression in the cavernosal artery that feeds the penis. He used three different methods (X-ray, ultrasound and arterial pressure readings) to gauge the effects of sitting on a narrow unpadded saddle, a wide padded saddle and a chair. From a test group of 100 impotent patients studied over 10 months, he determined that it takes only 11% of a person's body weight to compress the artery. He measured a 66% average reduction in blood flow through the artery when subjects were on the skinny saddle, 25% when on the wide saddle and no change when seated on the chair. This led Dr. Goldstein to conclude that, for a given weight, the wider the surface area of the seat, the less the chance of compression.

"I cannot say that sitting on a bicycle seat causes impotence," explains Dr. Goldstein, "but I can go on record with supporting data to show that sitting on a bicycle seat compresses the artery. However, it's intuitive that if you took a straw and sat on it, a certain percentage of the time the straw would jump back and be a circular structure. But if you keep doing this, at some point the straw is going to take on a sort of oval shape [or flatten]. I can't prove that long-term compression causes impotency, but I kind of think it does in a very small percentage of cases."

Since this potential cause of impotency does not stem from one traumatic impact and, in some cases, can remain symptomless for years, it is worrisome for cyclists who put in many miles. It may be akin to the gradual build up of cholesterol in blood vessels. Only instead of fatty lipids accumulating on the artery wall, scar tissue is forming from all the rubbing and compression. Over time, this may narrow the artery enough to reduce blood flow and cause erection difficulties.

"If you add the insult of chronic compression to an older man who has the beginnings of arteriosclerosis, hypertension, a cholesterol and weight problem, then the straw won't necessarily rebound back as it would in a younger, healthy man," Dr. Goldstein adds. "I think that's where this fits in."

An associate professor of urology at the University of Southern California and the director of The Male Clinic in Santa Monica, California, Dr. Harin Padma-Nathan says he treats 50 to 100 cases of what he terms bicycle-related impotency annually.

Typically, the patient is either a roadie who has logged many, many miles on an unpadded saddle that was set fairly high, or a mountain biker who has been riding off-road trails aggressively. Both types are also usually quite lean, meaning they have even less cushioning in their nether regions.

But Dr. Padma-Nathan, who is a former student of Dr. Goldstein's, doesn't think that saddle compression alone causes impotency. Rather, he views it as just one of many factors in an aging man that can combine to sap potency.

"To be diabetic, to smoke cigarettes, to have high blood pressure or cholesterol puts you at definite risk for erectile dysfunction," he explains. "But to ride a bicycle? Perhaps it's a risk. It may just aggravate other factors."

Other urologists agree that there is probably a middle ground.

"I take what Dr. Goldstein says very seriously," says Richard Lieberman, M.D., a clinical associate professor of surgery (urology) at Pennsylvania State University, who has treated impotent cyclists at his Allentown, Pennsylvania-based practice, "but I can think of a lot more things that are deleterious to one's health that should be outlawed before bikes. In fact, the overall vascular health of the cyclist may, in a lot of cases, outweigh some of the local deficit that's created."

In other words, if it wasn't for cycling, and the clean arteries and powerful hearts it fosters, there might be a lot more impotent older men out there.

Dr. Padma-Nathan, who rides a stationary bike every day to stay in shape, actually groaned when he heard that Dr. Goldstein was advocating banning bicycling. "There's no doubt there's a real issue here," he says, "but bicycling is an important form of cardiovascular exercise. Rather than terminate it, I would recommend tailoring this information to your own bicycling and body type."

In an attempt to clear the controversy, Dr. Goldstein is conducting an ongoing survey of his cycling patients to pinpoint commonalties of cause. He's also analyzing thousands of questionnaires from Boston-area cycling and running clubs in an attempt to compare incidents of impotency between sports. We'll let you know the results as soon as they're compiled. In the meantime, there are a number of things you should keep in mind to protect your potency:

- Penile numbness and excessive genital shrinkage are warning signs that there may be too much pressure on your crotch. The nerves in the perineum are being pinched, which means the artery that feeds the penis is also being compressed.

- Make the following changes in your riding style and/or your positioning on the bike: 1) Make sure your saddle is level, or point the nose a few degrees downward. 2) Check to see that your legs are not fully extended at the bottom of the pedal stroke. Your knees should be slightly bent to support more of your weight. 3) Be wary of spending significant time on aero bars: they encourage riding on the nose of the saddle. 4) Stand up every 10 minutes or so to encourage blood flow.

- There are a multitude of anatomic racing saddles on the market, ranging from ones with a flexible nose to models with a hole in the middle. Although Dr. Goldstein has not tested these special seats, he's skeptical of any design that fits between the sit bones. Instead, you may want to experiment with a wider, more heavily padded brand.

- Heavier riders may be more at risk of arterial compression damage because of the greater weight that's placed on the perineum. If you're in this category, you should consider a wider saddle with extra padding.

- When riding a stationary bike, the tendency is to stay seated and grind against big gears for long periods. Get out of the saddle as frequently as you would on your regular bike and be certain that it's set up the same in regards to riding position.

- When you straddle your bike, make sure the top tube is three to four inches below your crotch. Consider padding the top tube.

- Get out of the saddle when riding over railroad tracks, trail debris or washboard terrain. Use your legs as shock absorbers.

- Test-ride a recumbent. Since you're in a reclining position on a chair-like seat, Drs. Goldstein, Padma-Nathan and Lieberman all agree that there's little, if any, chance of compression or impact injury.

As Richard Belmont, the patient who experienced penile numbness on a 200-mile ride puts it: "The thing that angers me most in all of this is my own stupidity. I had absolutely no idea I could become impotent by riding a bicycle. If I had known, I would have ridden smarter. I think a lot of guys out there need to get that message."


Joe Kita, a former executive editor of Bicycling, is still riding his bike.

(If you've experienced cycling-related impotence we'd like to hear from you. Write in confidence to Ed Pavelka, c/o Bicycling, 135 N. 6th St., Emmaus, PA 18098.

Or send an e-mail to Ed Pavelka at LongRider@aol.com)

Is there Danger for Women, too?
First Person: The Down Side of Cycling

by Ed Pavelka

 

 

Should a cyclist be concerned if his or her crotch becomes numb while riding?

A: Yes. Numbness is caused by the saddle's compression of the perineum. In a male, this is the area of the crotch that houses the nerves and blood vessels that feed the penis. According to Boston urologist Irwin Goldstein, MD, long-term compression might result in arterial damage. He says blood flow may be so reduced that the cyclist could become impotent (unable to gain or retain an erection sufficient for intercourse). More common is reduced sexual sensitivity caused by numbness that can last for hours or days. This is also a problem reported by female cyclists. It helps to understand the male plumbing. The penis is a hydraulic system. During sexual stimulation, its twin chambers fill with blood until it's firm and erect. The mental impulse for this increased blood flow, and the flow itself, travel through the perineum. This is located between your "sit bones." To better understand the geography, squat and sit on a low step or curb. You'll feel your weight being supported by the two large bones of your pelvis, as evolution intended. But when you're on a bicycle seat, your weight may be concentrated between these sit bones, directly on the perineum. "Fifty percent of the penis is actually inside the body," Goldstein explains. "When you sit on a bicycle seat you're putting your entire body weight on the artery that supplies the penis." Of equal concern to Goldstein are accidents that cause impacts against the top tube or stem, causing injuries that leave a male unable to function sexually. "I cannot say that sitting on a bicycle seat causes impotence," Goldstein says. "But I can go on record with supporting data to show that sitting on a bicycle seat compresses the artery." He suspects that chronic compression results in scar tissue or flattening that reduces the ability of blood vessels to fill the penis. Because penile nerves pass through the same area, numbness can be considered a warning men must heed. To combat temporary numbness and the risk of greater dangers, use these tips:

1. Check saddle width. If it doesn't support your sit bones as well as a curb, it's too narrow. In addition, it should be flat (not bowed upward in the center) when viewed from the rear, and it should be almost flat when viewed from the side. You need to be supported primarily by your sit bones with minimal pressure on your perineum.

2. Beware of thick padding. It can bulge upward in the center as your sit bones depress the sides, putting pressure right where you don't want it.

3. Level the saddle. Or point the nose a degree or two downward to ease the pressure on your crotch if you frequently ride in a low position.

4. Lower the saddle. Your knees should be slightly bent when your feet are at the bottom of each pedal stroke. (See the "Ride It Right" articles on pages XX-XX.) This will prevent rocking across the saddle and let your legs support more of your weight.

5. Be wary of aero bars. For all their advantages, they encourage you to stay seated and ride on the saddle's nose for long periods, putting excessive pressure on your crotch.

6. Stand to pedal every 10 minutes. This will open your blood vessels and restore maximum circulation. Do this whether riding outdoors or in.

7. Use your legs as shock absorbers. Level the pedals and rise a couple of inches from the saddle for railroad tracks, patched pavement, washboard ripples, or anything else that can jolt your crotch.

8. Check your bike size. When straddling your road bike, there should be at least two inches between your crotch and the top tube, or as many as four inches for a mountain bike. This is a safety margin to reduce the risk of an impact injury.

9. Ride shorter. You don't need to be in the saddle for three hours to get a good workout. Less than half this time will do if you stress quality over quantity.

10. Crosstrain. Any sport, when taken to the extreme, can have injurious overuse effects. If you're seeking weight control and fitness, try activities that add enjoyment and subtract saddle time. 11. Heed numbness. If you lose sensation in your genitals while riding, it's a sure sign that you are compressing nerves and quite possibly blood vessels. Do not accept this as "part of the sport." Use these tips to find a solution, or try the new compression-relieving seat designs now hitting the market. --Joe Kita of Men's Health