Just read a New Scientist article where they discuss techniques athletes use to decrease the times it takes to heal from injuries. One technique is called "Blood Spinning". It uses your own blood to create more NGF plasma like paste that is either injected into the injuried site or is placed on the injury. This is supposely can actually decrease the times it takes to heal and make the area injured much stronger and resistant to a future injury.
WADA is already considering banning this technique although it isn't proven to give you an competive edge. Incredible. I will post more later once I learn more about it myself.