Stephen Colbert hit the gym with Supreme Court Justice Ruth Bader Ginsburg to try the workout that keeps her in shape and out of retirement.

“Which is surprising because if I had a lifetime appointment to a job that let me wear a robe, I would definitely let myself go,” Colbert said during Wednesday’s episode of “The Late Show.”

Colbert met up with Ginsburg and her trainer at the gym inside the Watergate Apartments in Washington, D.C.

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She was wearing a “Super Diva” sweatshirt and told Colbert she normally listens to opera music.

“I’m cramping and I’m working out with an 85-year-old woman,” Colbert said during the exercises.

But he was able to crack a few jokes.

“How strong are you on the Second Amendment? Because, welcome to the gun show!” Colbert said, flexing his biceps.

The pair also talked about her role as a feminist icon and her nickname — the Notorious R.B.G — which emulates the famous rapper Notorious B.I.G.

She said people have asked her what she has in common with the rapper.

“We have one thing in common and that is we were both born and bred in Brooklyn, New York,” Ginsburg said.

"You’re always spitting your truth,” Colbert responded.

A documentary about Ginsburg entitled “RBG” is scheduled to be released in early May.

Ginsburg is the oldest sitting justice on the Supreme Court and has said she plans to stay there for as along as she is able to.

“As long as I can do the job full steam, I will be here,” she said in January.

Colbert told her she needs to “just hang in there” for three to seven years — the rest of the Trump presidency.