I read an article years ago about how damaging long distance cycling can be to the testicles. Some of the men had balls hard as rocks. I thought ummm Get off the bikes dudes!...
I had a friend who was serious about bike riding--not to the extent that he raced competitively or anything--but enough that he had a quality bike and the outfits and equipment to match, in the same way that some people are serious about going to the gym and working out. He was riding his bike all the time, frequently challenged himself with long rides. He was also on prescription painkillers because his groin/testicles hurt so much, and having a sex life was pretty much impossible for him; other men have problems with pain, numbness, and erectile dysfunction. As for why he kept riding, I think the only conceivable answer is because he loved it.
Allegedly, ergonomic "no nose" bike seats reduce this problem.