The workout that keeps Ruth Bader Ginsburg fit at 84 is so intense you might not be able to keep up

Justice Ruth Ginsburg
Joanne Rathe | The Boston Globe | Getty Images

In February, Supreme Court Justice Ruth Bader Ginsburg was asked who she thinks is the most important person in her life. She jokingly replied, "My personal trainer," according to Mercury News. And it shows.

At 84, Ginsburg is the oldest sitting Supreme Court justice. In one month, her fitness routine will be revealed in the upcoming book, "The RBG Workout...How She Stays Strong ... and You Can Too!"

The book was written by Ginsburg's personal trainer, Bryant Johnson, who has trained her since 1999 and works with her twice a week, according to the Chicago Tribune.

The "simple but challenging" exercises include squats, planks and full push-ups (no knees on the ground), the Associated Press notes.

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Ginsburg told the 7th U.S. Circuit Court of Appeals Judge Ann Claire Williams that her trainer was solicited by numerous publishers who wanted to know what she's been up to and how she stays fit, according to the Tribune. "This book tells it all," she said.

The justice began exercising almost two decades ago after battling colorectal cancer, says the Associated Press. Ginsburg said her husband told her she needed to do something to get her strength back because she "looked like a survivor of a concentration camp."

Ginsburg, who has battled cancer twice, attributes her lengthy career as a liberal legal legend to her hour-long workouts. But she's not the only leader who has touted the benefits of a sweat sesh.

Self-made billionaires Mark Zuckerberg, Richard Branson and Oprah Winfrey all agree that exercise has been essential to their success.

Zuckerberg believes that to do anything well, you must have energy, which he derives from staying active. "I make sure I work out at least three times a week — usually first thing when I wake up," said the Facebook founder in a Q&A on his social site.

Oprah Winfrey
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Winfrey tries to work out daily, which for her means yoga and walking 10,000 steps a day. "I try to do something every day that allows me to feel active," the media mogul told People.

Branson explained on his blog that he enjoys physical activities such as running, playing tennis and biking.

"I seriously doubt that I would have been as successful in my career and happy in my personal life," said the serial entrepreneur, "if I hadn't always placed importance on my health and fitness."

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