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Michael Phelps is a former holder of world junior records for the 50 meter backstroke, 50 meter butterfly, 100 meter breaststroke, and 200 meter individual medley. He set these records in 2001 and 2002, when he was 15 and 16 years old, respectively. Phelps has since broken all of these records, as well as many others. He is considered to be one of the greatest swimmers of all time.