Please note that although the discussion that follows is specifically about cycling, it is relevant to any activity that places prolonged pressure on the saddle region of our bodies, including motorcycle, moped, and horseback riding. Also please note that this blog was published in an abridged version in the July 2014 edition of Masterlink, the newsletter of the Bicycle Touring Club of North Jersey.
Historical Trivia: Hippocrates reported sexual dysfunction among the wealthy residents of Scythia and judged excessive horseback riding to be the culprit.
Indisputable Fact: When sitting on a saddle, one places a much greater amount of body weight on the perineum (area between the genitals and anus where the genital blood and nerve supply lives) than one would otherwise, putting anatomy that is usually well protected into a vulnerable situation. The million-dollar question is whether or not this has the potential for a permanent injury.
Bottom Line: Cycling is an enjoyable recreational sport that provides a fabulous low-impact aerobic workout. It can result in outstanding cardiovascular health and fitness, the achievement of which is beneficial to sexual health. However, unlike running or swimming, cycling necessitates human interfacing with machine and contact points between the cyclist and the bike; these include the hands (on handlebars), feet (on pedals) and perineum (on saddle). Long distance cycling—in which prolonged time is spent in the saddle—can potentially adversely affect sexual function by causing compression trauma to the nerves, blood vessels, and muscles that support genital health and sexual function in both men and women.
As shocking as it seems, the male and female genitals are much more similar than one might imagine, as they share a common embryological origin. In embryological terms, the penis and the clitoris are the same structure, as are the scrotum and outer labia. The female is the default model that develops in the absence of testosterone; however, in the presence of testosterone, the clitoris becomes masculinized into the penis and the labia majora fuse to become the scrotum. Also virtually identical are the genital blood and nerve supply as well as the perineal muscles that support the genitals. What is different among the genders is the pelvic bone anatomy, with women having a much more open pubic arch and a wider distance between the ischial tuberosities (sit bones). Because of the perineal anatomical similarities among the genders, both men and women are susceptible to activity-related perineal trauma.
Healthy sexual functioning requires the on demand delivery of adequate volumes of oxygenated blood to the genitals. In terms of male sexual function, this penile surge of blood can occur within seconds and blood flow is increased by a factor of 40-50 times over baseline, a marvel of human engineering.1 Any compromise to blood flow may adversely affect a man’s ability to obtain and maintain an erection. With regard to female sexual function, blood flow compromise can negatively impact the ability to attain clitoral engorgement and vaginal lubrication.
The following is a simplified version of what happens in an arousing sexual situation, important foundational information for understanding why prolonged time in the saddle may potentially compromise sexual function. Under erotic circumstances, genital nerves release chemical mediators that increase arterial flow. Blood floods into the genitals and engorgement of the vascular sinuses of the penis and clitoris occur. As the process continues, the penis and clitoris become increasingly rigid. The bulbocavernosus and ischiocavernosus muscles of the perineum engage, their contractions further supporting penile and clitoral rigidity. In the female, the increased blood flow results in lubrication to the vagina. At the time of orgasm, the perineal muscles in both men and women contract rhythmically and in the male they facilitate ejaculation by propelling semen through the urethra.
Every tissue of our body is reliant on the nervous and the vascular systems for proper functioning. The nervous system is the electrical circuitry that provides sensation to touch, the ability for muscles to contract and thus motion, and the message to blood vessels to change in diameter. The vascular system is the lifeline of blood vessels that bring oxygen and nutrients to our tissues. The pudendal nerve is the main nerve of the genitals and is situated in the perineum. It provides sensation to the penis and clitoris, scrotum and labia, anal area and perineal skin, as well as motor function to the perineal and pelvic floor muscles. If the pudendal nerve gets traumatized it can cause numbness, a “pins and needles” sensation, and altered functioning of the perineal muscles. The pudendal artery is the main artery of the genitals and is also situated in the perineum, providing blood to the penis and clitoris, scrotum and labia, perineum and anus. It, too, must function properly as it is vital for sexual health.
Prolonged time in the saddle can compress and thereby “stun” the pudendal nerve and artery and can traumatize the perineal and pelvic floor muscles that support sexual function and are essential for penile and clitoral rigidity. Furthermore, the internal aspect of the penis and clitoris (the “root”) is anchored to the pelvic bones and is also subject to perineal compression as is the scrotum in men and the labia in women. The downward force of the cyclist’s weight while tilting forward on the saddle generates extreme pressure on the perineum that pinches the pudendal nerve and artery against the pubic arch.2 Both the duration and the magnitude of compression are factors in determining the degree of pudendal nerve and artery trauma.3 Pressure maps of the perineum demonstrate particularly high pressures on the saddle nose, under the cyclist’s pubic bone.4
Further compounding the issue is that there is a “steal” of blood flow from non-essential areas (including the genitals) to the muscles that are being utilized for the sport—in the case of cycling, the lower extremities being responsible for most of the work. Between the compromise to the penile and clitoral blood flow and the nerve supply, the direct effect of the compression of the perineal muscles and roots of the penis and clitoris, and the steal, there is a perfect storm for sexual dysfunction.5 Moreover, many cyclists are lean and their paucity of body fat does not provide much padding and insulation that could potentially offer some relief from saddle pressure. Over time, with repeated perineal stress to the pudendal nerve and artery, perineal muscles, and penile/clitoral roots, permanent damage may lead to sexual dysfunction.
Cycling-induced sexual dysfunction is a complex issue with multiple factors involved including the specifics of the geometry and hardness of the saddle, the anatomical variations of the individual, the amount of time spent in the saddle, the weight of the cyclist, the intensity of the cycling effort, and the particular style of sitting, which is nuanced and variable. Greater saddle width and the absence of a saddle nose have been demonstrated to be the most important factors in preventing arterial compression.6 If the saddle is not wide enough to support the ischial tuberosities (sit bones), then body weight is borne by the perineum. The wider saddles provide greater surface area that may allow the ischial tuberosities to bear more of the body weight.7,8 To reduce perineal compression, the back part of the saddle should be at least as wide as the distance between the two ischial tuberosities.9 However, too wide is no good because it may chafe the inner thighs. It is important for a saddle to be flat enough because if there is too much curvature, the center of the saddle can push up on the perineum and cause compression.
In addition to wide enough and flat enough, it is important that a saddle is firm enough. Gel saddles actually cause more trauma than unpadded saddles by virtue of the body sinking into the soft padding and the saddle thus squishing up into the perineum.10 The reduced surface area of saddles with a narrow cutout can actually increase the extent of the perineal pressure11 (on the edges of the cutout); however, for those cyclists who find that if they have a saddle that is sufficiently wide, flat and firm yet remains uncomfortable, they may need a cutout to help relieve some of the perineal discomfort.4
A horizontal or even downward-pointing saddle position has been associated with reduced perineal pressure.12 Heavier riders exert more pressure on their saddles than lighter riders.13 Lower handlebars may exacerbate perineal stress by forcing the rider to lean forward, putting more body weight on the perineum.14 Schrader15 did a study of male police officers recruited from several U.S. metropolitan areas who spent many hours a week in the saddle, testing the effectiveness of no-nose ergonomic saddles. After 6 months in a no-nose saddle, there was a significant reduction in saddle contact pressure with the perineum, improvement in penile sensation and better erectile functioning.
As a cyclist goes from sitting upright to the bent over aerodynamic position, the torso and pelvis rotate forward and the ischial tuberosities are lifted off the saddle surface, shifting more weight onto the perineum.4 This is clearly a superior position for time trials and triathlons, but inferior for one’s genital health. On the other extreme, when standing on the pedals, there is no perineal pressure and studies have shown that genital oxygenation is significantly increased.16,17 Interestingly, professional cyclists place less pressure on the saddle and appear to “float” over it.6 Mountain bikes have been associated with a greater degree of sexual dysfunction than road bikes,18 likely because of the additional perineal hammering and vibrational trauma from cycling over rough terrain; however, this is balanced to some extent by the use of suspension mechanisms, the increased time spent out of the saddle and more frequent dismounts.
The sexual dysfunction that may occur after a prolonged bike ride is often temporary, but can potentially become permanent if the perineum is subjected to chronic, sustained and repeated pressure trauma. It is much less likely to occur with recreational weekend cyclists and commuter cyclists who do not log in significant miles and more likely to occur in serious road cyclists and mountain bikers. It is estimated that 5% of men who cycle intensively have moderate to severe erectile dysfunction, and the number may be higher because many men are too embarrassed to discuss the issue or fail to make the connection between cycling and the resultant ED.13 Female cyclists have not been studied as closely as have male cyclists, but clearly cycling is potentially hazardous to a woman’s sexual health. Studies have shown that women cyclists as opposed to runners had significantly higher genital vibratory thresholds (reduced sensation) of the clitoris, perineum, vagina and labia.19
The first clue that trouble may be lurking is unusual sensations including genital numbness and tingling, symptoms commonly experienced by cyclists, correlating with time spent in the saddle.20 These are signs to shift position and perhaps assume a standing posture on the pedals to allow the symptoms to subside. Frequent subtle adjustments by shifting and shimmying and making an effort to sit on the ischial tuberositiesare helpful. Other measures one can take are wearing well padded cycling shorts and investing in a well-fitted seat tailored to the specifics of one’s anatomy. The saddle needs to be carefully adjusted and fine-tuned in terms of height and angulation to minimize perineal pressure
Dr. Arnold Kegel popularized pelvic floor muscle exercises in order to improve female sexual and urinary health after childbirth; his legacy lives on in these exercises that bear his name—Kegel exercises. Men have essentially the same pelvic floor muscles that women do and an equivalent capacity for exercising them, with a parallel benefit to urinary and sexual health. Cyclists can tap into their pelvic floor muscles to pump some “life” back into their compromised genitals after a long ride.5 Similar to using a bike pump to inflate tires so that they are well pressurized, with each contraction of the pelvic floor muscles, blood pumps into the genital tissuesto help “resuscitate” them. Performing Kegel exercises on a regular basis can help prevent perineal compression trauma by building bulbocavernosus and ischiocavernosus muscle strength and tone. Pelvic floor muscle exercises performed before, during and after cycling can help mitigate compression trauma. Most cyclists will periodically take a break from sitting in the saddle by standing up—this provides a perfect opportunity to take the pressure off the perineum and to do a few pelvic floor muscle contractions to restore genital blood flow.
Long distance cyclists may benefit from using oral medications for ED—including Viagra, Levitra, Cialis, and Stendra—to help maintain genital blood flow and oxygenation.21 These medications increase genital blood flow in both genders, and although research has only been reported in male cyclists, on a physiological basis there is no reason to believe why they would be any less effective in females.
Keys To Reducing Risk For Sexual Dysfunction
- Wear well padded cycling shorts.
- Be proactive—shift from sitting to standing every 10 minutes or so.
- When numbness and tingling occur, shift into an alternative position on the saddle and/or stand on the pedals.
- Sit back firmly on your ischial tuberosities and not on your perineum—as you shimmy from the saddle nose (which can really dig into your perineum) towards the back of the saddle (where you sit on your ischial tuberosities), you can feel your body engage properly.
- Invest in an ergonomic bicycle saddle tailored to the nuances of your anatomy—make sure it is wide enough to support your sit bones, firm enough so that your perineum doesn’t sink and flat enough so that you don’t slide and that it doesn’t wedge up under the perineum.
- Adjust seat and handlebar height and angle to minimize perineal compression.
- Do pelvic floor muscle contractions periodically while cycling and pelvic floor exercises when not cycling.
- If you start having sexual issues, seek help pronto…help is available!
Final word: Cycling is an awesome sport that occasionally may contribute to male and female sexual dysfunction, especially for serious cyclists who spend prolonged time periods in the saddle. Pay careful attention to your perineum, very valuable human real estate that contains structures that are vital to sexual health.
About the author: Andrew Siegel (www.AndrewSiegelMD) is a physician in practice at Hackensack University Medical Center who is board-certified in urology and female pelvic medicine/reconstructive surgery. He is a recreational cyclist who is a member of Bicycle Touring Club of North Jersey and is the author of three books, the most recent being Male Pelvic Fitness: Optimizing Sexual and Urinary Health. (www.MalePelvicFitness.com)
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