If suffering on the bike isn't enough, how about the UNplanned mishaps that are part of racing? I'll start with one of the worst ever, the last stage of the 1994 Tour where a camera-toting policeman took out Laurent Jalabert (around the 2:50 time marker in the video below of Tour crashes).
http://www.youtube.com/watch?v=lOmx9J1jwAo&feature=related
http://www.youtube.com/watch?v=lOmx9J1jwAo&feature=related