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FILE - In this Aug. 9, 2016 file photo, U.S. gymnasts, from left, Simone Biles, Gabrielle Douglas, Lauren Hernandez, Madison Kocian and Aly Raisman hold their gold medals during the medal ceremony for the artistic gymnastics women's team at the 2016 Summer Olympics in Rio de Janeiro, Brazil. MTV said Thursday, Aug. 25, that Biles, Raisman, Douglas, Hernandez and Kocian along with swimmer Michael Phelps, will present awards at Sunday’s MTV Video Music Awards in New York. (AP Photo/Julio Cortez, File)

Michael Phelps

Olympic champion Michael Phelps has announced his intention to retire after the London Olympics.