It’s common knowledge that biking can really mess with a man’s sex life. A number of times, during a long bike ride, I would go completely numb from the navel to the knees. When I asked around, a lot of other guys were having the same problem. The problem is that pressure from the seat can cut off circulation to the groin. Less blood flow leads to fewer (and weaker) erections.
Turns out that biking cans cause some problems “down there” for women: