The men's world record has been improved upon twelve times since electronic timing became mandatory in 1977.  The current men's world record of s is held by Usain Bolt of Jamaica, set at the 2009 World Athletics Championships final in Berlin , Germany on 16 August 2009, breaking his own previous world record by s.  The current women's world record of s was set by Florence Griffith-Joyner of the US, at the 1988 United States Olympic Trials in Indianapolis , Indiana, on 16 July 1988  breaking Evelyn Ashford 's four-year-old world record by .27 seconds. The extraordinary nature of this result and those of several other sprinters in this race raised the possibility of a technical malfunction with the wind gauge which read at m/s- a reading which was at complete odds to the windy conditions on the day with high wind speeds being recorded in all other sprints before and after this race as well as the parallel long jump runway at the time of the Griffith-Joyner performance. All scientific studies commissioned by the IAAF and independent organizations since have confirmed there was certainly an illegal tailwind of between 5 m/s - 7 m/s at the time. This should have annulled the legality of this result, although the IAAF has chosen not to take this course of action. The legitimate next best wind legal performance would therefore be Griffith-Joyner's performance in the final the next day. 
Prior to the Olympic competition, several prominent athletes were ruled out of the competition due to failed tests. World indoor medallists Dimitrios Chondrokoukis , Debbie Dunn , and Mariem Alaoui Selsouli were withdrawn from their Olympic teams in July for doping, as was 2004 Olympic medallist Zoltán Kővágó .    At the Olympic competition, Tameka Williams admitted to taking a banned stimulant and was removed from the games.  Ivan Tsikhan did not compete in the hammer throw as a re-test of his sample from the 2004 Athens Olympics , where he won silver, was positive.  Hassan Hirt ,  Amine Laâlou ,  Marina Marghieva ,  Diego Palomeque ,  and defending 50 km walk champion Alex Schwazer were also suspended before taking part in their events.