Watch: Michael Phelps retires

RIO DE JANEIRO, Aug. 14 (UPI) -- Phelps out.

The most decorated Olympian in history is retiring after claiming five gold medals in Rio de Janeiro.

"We're not going four more years, this is it," Phelps said on Facebook Saturday. "Tonight's the last time that I'll be suiting up and racing at this level. I'm not swimming Masters, either, no offense to Masters."

Phelps later helped the United States set an Olympic record for a gold medal in the men's 4x100-meter medley relay final.

He finished his Olympic career with 23 gold medals.

"Going for 30 medals in Tokyo, I don't think so, boys and girls," Phelps said. "This is over, this is it. It's a lot to think about, 24 years in the sport and we're finishing up tonight."

But Phelps' Olympic teammates aren't too quick to believe the swimming legend.

"Last time was his last, this time was his last, and I get to say I was on the same team twice when he retired," Ledecky told the Washington Post. "Maybe there will be a third time. All records are made to be broken."

Ryan Lochte even "guaranteed" Phelps would participate in the 2020 Summer Games in Tokyo. "He said he was going to retire after 2012, and I was the only person who said he was going to come back again," Lochte told NBC.

The video has more than three million views.