Most men can tolerate a bit of discomfort and even pain when they're cycling, but numb testicles are likely to raise concern. This concern is well-founded. Although the short-term effects are not serious, cycling can cause damage to the male reproductive organs over time. But that doesn't mean you should stop cycling. Using proper equipment can prevent numb testicles, and cycling can actually improve the health of your reproductive organs.
Testicular numbness is a common side effect of cycling for men, particularly after a long ride. According to the Dr. Irwin Goldstein of the Boston University School of Medicine, this is because of compression changes during cycling that cause a reduction in penile blood flow. Goldstein explains that the blood flow is reduced when a cyclist is seated, but returns to normal when he lifts himself off the seat. The numbness, however, may remain well after the end of a bike ride.
Testicular numbness is usually temporary and only mildly annoying, according to the website of the urology department at the Stanford Medical School. But it can cause long-term problems. Dr. Robert Kessler, a professor of urology at Stanford, explains that cycling can cause long-term damage to the genital area of male riders. Over time, male cyclists who ride frequently may develop erectile difficulties because of the restricted blood flow. This is caused by localized atherosclerosis, a blockage of the penile artery.
According to Kessler, cyclists can achieve temporary relief from numb testicles by shifting their position on the seat and by standing up. But for permanent relief, he recommends using a specialized bike seat. Heart-shaped cycling seats with a depression in the center take the pressure off the perineum, allowing blood to flow to the penis and testicles. Kessler cautions men not to wait for the symptoms to develop but to use one of these seats as a preventative measure.
Don't let the fear of erectile difficulties scare you away from cycling. It's a safe activity if you use a proper seat, and it can actually reduce your chances of developing erectile problems. According to Goldstein, cycling reduces your chances of developing hypertension -- a condition that can cause erectile dysfunction. He notes that sedentary men have a greater risk of developing erectile difficulties than cyclists.