Michael Phelps Shares Photo of His Insane Abs in Last Swim Practice Before Rio

Michael Phelps (and his abs) are off to Rio!

The 2016 Summer Olympics in Rio are just days away and, with that, 31-year-old Phelps has wrapped up his final practice in the United States.

"Last practice on American soil complete !! Nothing like a little fun afterwards with the crew!! #number5 #letsdothis #mp #mpswim," Phelps captioned an Instagram photo of himself with some friends – as he showed off his athletic body in a pair of Speedos.

Phelps is no stranger to the famous Games, though. This year marks Phelps' fifth time competing in the Olympics – he is the only male swimmer to make five Olympic teams.



In addition, he is the most decorated Olympian of all time.

WATCH: Does Michael Phelps Already Have a Future Olympic Swimmer on His Hands?!

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The road to becoming Olympic royalty wasn't easy for Phelps, though. The athlete has made a remarkable turn-around since entering rehab for substance abuse in 2014.

Phelps' sister, Hilary, previously told PEOPLE that his time in rehab has made him more approachable to his teammates.

"There was a feeling that people wanted to give him space. Now that he's more grounded, he's warmed up and people have warmed up to him," she said.

"He's let people know, 'I've made mistakes, like everyone else. I'm human.' And people respond to that."

Heading in to this year's Olympics, Phelps will serve, alongside five of his veteran teammates, as captain of the Rio-bound U.S. swim team.

Phelps will compete in three individual categories when swimming events kick off on Saturday.

To learn more about all Olympic hopefuls, visit teamusa.org. The Rio Olympics begin August 5 on NBC.