Michael Duane Johnson (born September 13, 1967) is a retired American sprinter. He won four Olympic gold medals and eight World Championships gold medals. He formerly held the world and Olympic records in the 200 m and 400 m as well as the world record in the indoor 400 m. He also once held the world's best time at 300 m. Johnson is generally considered one of the greatest and most consistent sprinters in the history of track and field. He is the only male athlete in history to win both the 200 meters and 400 meters events at the same Olympic…