Cycling: Can it make a man infertile?

Dear Alice,

I'm a man and I'm engaged in a lot of sports and outdoor activities, but lately some of my friends said that biking could result in male infertility. Is this true? How? What are the other activities that could lead to male infertility? How can I stay healthy in terms of fertility?

Dear Reader,

Talk about news that can send you flying off the handlebars! What your friends mentioned may have some truth to it, but it's good to keep in mind that fertility depends on a variety of factors related to the quality and quantity of sperm that you produce. Simply biking for sport may not be the sole cause of infertility. Additionally, there are some strategies you can take to help maintain sperm health, both on and off the bike. So, don't bring your wheels to a screeching halt just yet!

Male infertility ultimately comes down to the testes' ability to create an adequate amount of functional sperm. Anything that impacts the ability of the testes to make that sperm could lead to some form of male infertility. One of the more common causes of inadequate sperm production is higher scrotal temperature, which may, in turn, affect sperm count. The scrotum, which is located behind the penis outside of the body, holds the testes (which then produce sperm). Turns out, the testes are quite testy when it comes to ideal temperature. To produce the ideal amount of sperm, the scrotum needs to be slightly lower than body temperature, hence their location on the outside of the body. Scrotal temperature may be affected by a number of circumstances, including sitting on a bicycle seat for over 30 minutes, wearing tight underwear, sitting for a long time, and using laptops directly on your lap.

The ability to have an erection may also affect fertility. It’s been suggested that biking may be related to erectile dysfunction (ED) and other injuries of the groin in those with a penis who ride their bikes more than three hours per week. However, this research remains inconclusive. In fact, head injuries acquired from biking may be a more concrete contributor to ED than biking itself due to injuries to parts of the brain necessary for successful sexual function. Overall, more research needs to be done to understand these relationships.

So what's a biker to do? For starters, you may want to be a little like Goldilocks by looking for a bike seat that's just right: one that’s neither too hard nor too narrow, but one that is ergonomically designed to address this issue. Someone working at a bicycle shop may be able to help you choose a seat. Once you’ve found one that’s right for you, it's a good idea to keep your weight balanced on your "sit bones" (i.e., ischial tuberosites) to avoid putting pressure on the perineum and genital area. After you get on the road, taking breaks from biking is another way of having your bike and riding it, too.

Generally speaking, many of the contributors to male infertility can easily be remedied. To help mitigate any potential risk you may incur from riding your bike, you can try a few strategies. The first is to consider taking antioxidant supplements, such as vitamin C and vitamin E, which could improve the amount and functionality of any sperm you produce. Another way to protect your sperm health is to avoid jumping in the hot tub after a nice bike ride as the heat may affect sperm quality. If you would like more specific information and resources related to your own sperm production, it may be a good idea to talk with your health care provider about options that are best for you.

Happy (bike) trails to you!

Last updated Nov 06, 2020
Originally published May 30, 2003

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