(Reuters) - American swimmer Missy Franklin announced her retirement on Wednesday at the age of 23, ending a successful career in which she won five Olympic gold medals.
She was one of the stars of the 2012 London Games, where as a 17-year-old she won the 100 and 200 metres backstroke events, the latter in a world-record time.
Franklin was also part of two victorious U.S. relay teams.
She never improved her personal best times from London, but made the U.S. team for the 2016 Rio Olympics, where she picked up another relay gold after swimming in the heats.
"This was perhaps the hardest letter I’ve ever had to write ... Today, I announce my retirement from competitive swimming," Franklin wrote on Twitter.
(Reporting by Andrew Both in Cary, North Carolina, editing by Ed Osmond)