Over the years, 86-year-old Supreme Court Justice Ruth Bader Ginsburg has become somewhat of a fitness icon.Working out with a personal trainer is a key part of her health routine and has allowed her to stay energized in her 26th year serving on the United States Supreme Court.In a recent interview on Bloomberg’s “The David Rubenstein Show: Peer to Peer Conversations,” Ginsburg explained that her commitment to her workouts also helps her maintain work-life balance.”Sometimes I get so absorbed in my work I just don’t want to let go,” Ginsburg said. “But when it comes time to meet my trainer I drop everything.”Occasionally Ginsburg said she’ll feel tired at the start of a workout, but afterwards “I always feel much better,” she added.Exercise wasn’t always such an integral part of RBG’s daily routine. She told Rubenstein that her late husband Martin Ginsburg initially suggested she take up exercise after she completed chemotherapy for colon cancer in 1999.”He said, ‘We must do something to purge yourself of [the cancer],'” she recalled.That’s when Ginsburg met her long-time trainer, Bryant Johnson, who published the book “The RBG Workout” in 2017, and is still her trainer to this day.Johnson told CNBC Make It in 2018 that exercise seems to be a welcome respite from the rest of Ginsburg’s day, which is why she feels re-energized afterwards. “She’s just working out,” he said. “It gives her brain time to rest and recharge.”Although their sessions are a mental break, they’re physically quite demanding.Ginsburg typically does a combination of cardio and strength training exercises, such as planks and push-ups, and they will plan the hour-long routines months ahead of time, Johnson told CNBC Make It.Given Ginsburg’s demanding schedule and night owl tendencies, their sessions usually take place at night. “She can come in there with only one hour of sleep, or two hours of sleep, and she is still committed to doing the work out,” Johnson said.Another thing Ginsburg is committed to? Her job. In late August, Ginsburg was treated for a tumor on her pancreas, but she reiterated to Rubenstein that she intends to stay on the court “as long as I’m healthy and mentally agile.”Like this story? Subscribe to CNBC Make It on YouTube!