Protect your perineum!
"Cycling Down Under"
"Rest your crotch for hours at a time on a piece of leather only a few inches wide, and you're bound to have some problems. Repeatedly pump your thighs up and down against the leather while wearing tight Lycra shorts, and the complications multiply. Bounce delicate body parts against the leather as you transverse rough roads, and it's time to seriously reconsider the meaning of life. Cycling can induce a plethora of nether-region injuries that range from annoying to devastating.
The crotch itself doesn't normally bear weight; it's the job of the ischial tuberosities, or sit bones. Ideally this part of your anatomy should contact the saddle. However, with poor bike fit or in an effort to achieve an aerodynamic position, part of your body weight can rest on soft tissues with painful consequences."
Potomac Cycling Club, USA www.bikepptc.org
Medical problems and research associated with cycling...