Sport is dangerous. Today’s athletes decide to endanger their lives by participating in sports all the time. They decide to participate in sports with the informed decision that they might get hurt as it is part of the sport. Performance enhancing drugs are no different.  In the USA every year there are nearly 300,000 sports-related traumatic brain injuries (TBIs). Athletes involved in sports such as football, hockey and boxing are at significant risk of TBI due to the high level of contact inherent in these sports. Head injuries are also extremely common in sports such as cycling, baseball, basketball and skateboarding. Many head injuries acquired, playing these sports, lead to permanent brain damage or worse. Yet we do not impose a law to ban athletes from participating in those sports. We trust their assessment of risk (1).  All about Traumatic Brain Injuries:  , accessed 05/15/2011