Cycling is a popular mode of aerobic fitness that burns calories while strengthening the leg muscles.

More than one-third of Americans ride a bike. Some people occasionally cycle for fun, and other people are more serious riders who spend hours a day on a bike.

But people who have a penis and who bike can experience erection problems as an unintended consequence of spending too much time on a bike seat.

The link between riding and erection problems isn’t new. In fact, the Greek physician Hippocrates identified sexual issues in male horseback riders when he said, “The constant jolting on their horses unfits them for intercourse.”

Here’s why riding a bike can affect your ability to achieve an erection, and how to prevent cycling from putting the brakes on your sex life.

When you sit on a bike for long periods of time, the seat puts pressure on your perineum, an area that runs between your anus and penis. The perineum is filled with arteries and nerves that supply oxygen-rich blood and sensation to your penis.

For a man to have an erection, nerve impulses from the brain send arousal messages to the penis. These nerve signals allow blood vessels to relax, increasing blood flow through the arteries into the penis.

Any problem with the nerves, blood vessels, or both can make you unable to have an erection. This is called erectile dysfunction (ED).

Over the last few decades, researchers have discovered that some male cyclists develop damage to the pudendal nerve, the main nerve in the perineum, and the pudendal artery, which sends blood to the penis.

Men who spend a lot of hours on a bike have reported numbness and trouble achieving an erection. Experts believe ED starts when arteries and nerves get caught between the narrow bicycle seat and the rider’s pubic bones.

With a few modifications, you can still ride for exercise and enjoyment without sacrificing your love life.

Here are a few modifications you can make to reduce your risk of ED:

  • Change your seat. Switch out your narrow bicycle seat for something wider, with extra padding that supports your perineum. Also, choose a seat without a nose (it’ll have more of a rectangular shape) to reduce pressure.
  • Lower the handlebars. Leaning forward will lift your backside off the seat and relieve pressure on your perineum.
  • Wear padded bike shorts. This will give you get an extra layer of protection.
  • Cut back on your training intensity. Cycle for fewer hours at a time.
  • Take regular breaks during long rides. Walk around or stand on the pedals periodically.
  • Switch to a recumbent bike. If you’re going to spend a lot of time on the bicycle, reclining is gentler on your perineum.
  • Mix up your exercise routine. Instead of cycling exclusively, switch between jogging, swimming, and other forms of aerobic exercise. Make cycling part of a well-rounded workout program.

If you notice any pain or numbness in the area between your rectum and scrotum, stop riding for a while.

Although it usually isn’t permanent, ED and numbness caused by cycling can last for several weeks or months. The easy solution is to cut back on bike rides or stop riding altogether.

If several months go by and you still have trouble achieving an erection, see your primary care doctor or urologist. A medical condition like heart disease, a nerve problem, or the residual effects of surgery might be other potential causes of your ED.

Depending on the cause of your problem, your doctor might prescribe one of the ED drugs you may have seen advertised on TV, including:

These drugs increase blood flow to the penis to produce an erection. But consider them carefully — these medications can have serious side effects.

ED drugs are not recommended for those who take nitrates (nitroglycerin) for chest pain or for people with very low or high blood pressure, liver disease, or kidney disease. Other medications are also available to treat ED, as well as nondrug options like penis pumps and implants.

Learn about five herbs that can be used to help treat ED.

You don’t have to give up cycling if you’re experiencing ED. Simply make a few modifications to your ride.

If you do develop ED, talk with your doctor about what’s causing the problem and find the solution that’ll safely and effectively restore your sex life.