The three-time gold medalist Usain Bolt is considering a run at Michael Johnson?s 400-meter world record. Bolt cruised to world-record victories in the 100 and 200 at the Beijing Olympics. Johnson set the 400 record of 43.18 seconds in 1999. ?There are no major championships in 2010, so I could go for the 400-meter record that year,? Bolt said in a BBC interview. ?The training for 400 meters is so much harder, but I?m thinking about it.?.