No one was faster than Johnson. The Jamaican-born Canadian sprinter set the world record for the 100-m dash at the 1987 World Championships and then broke it at the 1988 Summer Olympics, winning the gold. But then he was brought down by you guessed it steroids. Johnson tested positive for Stanozolol, a testosterone-based steroid often used in bodybuilding. He was stripped of his medal as well as his two world records. Johnson made a brief comeback but was found guilty of doping in 1993 and again in 1999 this time, for a banned diuretic used to mask other drugs. That same year, Libyan leader Muammar Gaddafi hired Johnson to teach his son soccer.