U.S. sprinter Marion Jones competes in the women's 100 metre dash at the FBK Games in Hengelo, in the Netherlands in this May 29, 2005 file photo. At the 1988 Seoul Games muscular Ben Johnson exploded from the blocks to cross the line in 9.79 seconds, four hundredths of a second faster than his own world mark. This race resulted in the biggest drugs scandal to hit the summer Games when Johnson tested positive for the steroid stanozolol. The sport of track and field, and in particular the 100 metres, has struggled for credibility since. Jones confessed to being on a drugs regime in Sydney and was stripped of all her subsequent marks and times. Picture taken May 29, 2005. To match feature ATHLETICS-DOPING/JOHNSON REUTERS/Jerry Lampen/Files