The triple Olympic gold medal winning sprinter Usain Bolt has dismissed speculation his sudden success is aided by doping.
Prior to his efforts in Beijing Bolt had previously run only a handful of 100s and his world record performance raised eyebrows among some observers.
In a recent interview nine time Olympic champ Carl Lewis said he was trying to come to grips with Bolt dropping 10 flat to 9.6 seconds in one year.
Bolt says doping speculation comes with the territory but his 100 breakthrough was earned by hard training.
