Doping...
 

NASCAR effectively has no testing plan. Drivers sign contracts pledging not to use unspecified drugs the organization states "may affect adversely" the safety of competitors and fans, and NASCAR will test drivers and/or pit crews if it deems there is "reasonable suspicion."

hmmm... faster reaction time? or something to keep you from getting exhausted heat and other elements.

everyone loves the drugs!!

Seems to me they are more likely talking about the recreational kind that may decrease reaction time.

Like that one guy who was using heroin while driving