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Leo Rogier Verberne

2. Sexual organs

Lance Armstrong

Figure 1 Bent forward cycling position on a racing bicycle (Lance Armstrong / photo Livestrong)

When bending forward in a sitting position on a racing bicycle, sweat trickles down between the buttocks and across the anus. A piece of chamois in the cycling pants initially solves this inconvenience. But if the physical exertion is prolonged, the sweat, which contains intestinal bacteria and Candida, reaches the sexual organs. These may become inflamed as a result. In women, these microorganisms can cause a vaginal infection and bladder infection. An infected foreskin and glans in a cycling male may also cause a vaginal infection in the female partner. Washing with soap and water alone does not provide sufficient protection against infections of this kind. The use after cycling of a disinfecting agent, such as betadine, is essential to prevent this.

Figure 2 left: the upper triangle is the section supporting the body on a normal bicycle saddle;
right: blood vessels and nerves are present in the softer tissue between the sit bones (4)

If you sit upright when cycling on a regular bicycle, then your sit bones (ischial tuberosity) are supported by the bicycle saddle. The purpose of these bones is to support the body weight when one is sitting (figure 2). In the left sketch, the upper triangle corresponds to the spot where the buttocks rest on the bicycle saddle. The underlying sit bones are shown (in fine lines) in the drawing. In the right sketch, the sit bones are exposed. In the triangle in between (the crotch), the blood vessels and nerves run through the softer tissue to the sexual organs.

Regular racing bicycle
In the bent forward position, the crotch rests on the narrow racing saddle (figure 1). The tissue between the sit bones supports the weight of the body. But that softer tissue contains the blood vessels and nerves to the sexual organs. Blood vessels are pressed, almost shut, and nerves become pinched. After a while, this leads to numbness in the sexual organs or tingling and a burning sensation. This is the case for both men and women. Prolonged cycling on a regular racing bicycle can lead to impotence (erection problems) in males, which sometimes lasts a week or even up to a month or more (1). Because an erection requires stimulation of the nerves and is a blood vessel tour de force. And so you should not subject your crotch to pressure on a too narrow bicycle saddle for too long. Cycling should always be fun, for the partner as well. Males who regularly ride racing bicycles also experience pressure to the prostate. It is located in the lower abdomen around the urinary tract, just above the crotch. After hours of cycling in a bent forward position, the prostate can, in response to the pressure, swell in such a way that the urinary tract is obstructed. As a result, a professional cyclist cannot produce a urine sample for the dope test.

The saddle plays an important role in the occurrence of symptoms. In a study among 40 racing cyclists ranging in age between 25 to 35 years old, 28 of the participants (70%) were found to experience a considerably lower blood supply to the penis while cycling. Twenty-four (60%) experienced numbness of the penis and scrotum and 8 of the 40 cyclists (20%) experienced impotence (erection problems) (6). The decrease in blood flow to the penis proved to depend upon the saddle: the blood supply decreased by 82% (to 18% of the original level) on a narrow saddle. It decreased by 72% (to 28%) on the same saddle with a groove in the center. A wider and shorter saddle is found to be healthier for the sexual organs of men and women (5). The softness of the saddle, on the other hand, is not relevant to the blood supply (7). The outcome of these studies has been taken into consideration in some racing bicycle saddles (figure 3).

ISM PR 3.0
ISM PR 14.5

Figure 3 A shorter and wider racing bicycle saddle with a groove
ISM, PR 3.0; length 25 cm, width 14.5 cm (2)

Recumbent racing bicycle
If you ride a recumbent bicycle, you will not experience any pressure to the crotch. Symptoms resulting from a reduced blood supply to the sexual organs do not present themselves. However, the recumbent bike is also associated with a pressure problem. It concerns the back, which is pressed against the seat as one pedals. In the course of time, this may result in the development of a tubercle on the spine between the shoulder blades. X-rays show this not to involve a bone tumor, but rather connective tissue. Comparable to the knob that develops on the instep of those who wear wooden clogs. A groove in the center of the seat back will prevent this pressure to the vertebrae when riding a recumbent bicycle. The pressure when pedaling is then applied to the shoulder blades and not to the spine.

Figure 4 No pressure on the sexual organs when cycling recumbent

1. When riding a racing bicycle in the bent forward position, sweat increases the risk of an infection of the sexual organs.
2. The sexual organs of both males and females can become numb when riding a racing bicycle; men may experience impotence (erection problems) and swelling of the prostate.
3. A wider and shorter racing bicycle saddle with a groove in the center reduces pressure problems.
4. A recumbent bicycle is not damaging to the sexual organs, but it may cause pressure to the spinal column between the shoulder blades.

1.  KV Andersen, G Bovim (1997). Acta Neurol Scand. 233-240:
Impotence and nerve entrapment in long distance amateur cyclists
2. ISM zadels (2017): dé oplossing voor uw zadelprobleem
3. David Kopsky (2010): Wielrenners-neuropathie
4. Frank H Netter, The Ciba Collection of Medical Illustrations, vol. 2: Reproductive System.
Ed. Ernst Oppenheimer; Ciba Pharmaceutical Company; 3rd printing 1965; p 13 en 21
5. SM Schrader, MJ Breitenstein, BD Lowe (2008). J Sex Med. 1932-1940:
Cutting off the nose to save the penis
7. U Schwarzer, F Sommer, T Klotz, C Cremer, U Engelmann (2002). Eur Urol. 139-143:
Cycling and penile oxygen pressure: the type of saddle matters

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© Leo Rogier Verberne

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