The following is true for long-distance bicycle riding on a wide seat;
"The wide seat
distributes the body weight to the ischium or lower portion of
the hip bone, whereas the narrow seat puts undue pressure on
the penile arteries causing trauma to the sensory nerve that
governs erection. The resultant ischemia, due to obstruction of
the circulation, can cause permanent changes in the penile arteries
in direct relationship to the perineal trauma.
Narrow bicycle seats should be used for short sprints only, and
the wide bicycle seat should be adapted for all other uses."