Olympian Katie Ledecky established herself as a breakout star at Rio 2016. She is set to become the next face of US swimming, especially since gold medalist Michael Phelps has retired. Ledecky won five medals at the last summer games, four of them gold. Phelps recently said that Ledecky is "on fire." In an interview with Business Insider, he said, "It's a true treat for me to be able to see her kind of truly coming up in the sport like she is.