Bicycles were not designed with male genitalia in mind, and they account for more than 4,000 genitourinary injuries each year. A recent comprehensive review looked for conclusive evidence that bicycle seats also cause chronic issues, like erectile dysfunction, by compressing the pudendal nerve and vessels. 

In a paper published in Urology (2015;85:725-730), Mathias Michiels, MD, and Frank Van der Aa, MD, PhD, of KV Leuven in Leuven, Belgium, concluded that bicycle seats may result in transient genital numbness, but that there is no evidence the effects are permanent. Cyclists with occasional numbness should select a seat that fully supports the ischial tuberosities, then tilt the seat’s nose downward, avoid leaning forward for too long, and regularly stand up on the pedals.