Watchout biking. It may cause impotence. Not joking. http://healthlink.mcw.edu/article/1023994375.html http://healthlink.mcw.edu/article/1023994375.html That

Watchout biking. It may cause impotence. Not joking. http://healthlink.mcw.edu/article/1023994375.html http://healthlink.mcw.edu/article/1023994375.html That was the first link from google. There are others more informative. Make a few searches if interested.