Ruth Bader Ginsburg is an Associate Justice of the Supreme Court of the United States.

She does an incredibly intense workout with a personal trainer twice a week.

She’s also 83 years old.

Despite Ginsburg’s age, she is seemingly fighting fit - not just with her Liberal stance, but physically too.

When asked recently who the most important person in her life is, Ginsburg responded: “My personal trainer.”

How much she was joking is unclear, as she must be pretty serious about her fitness.

The personal trainer in question is a man called Bryant Johnson, who has been training Ginsburg since 1999.

The exercise it takes to burn off high-calorie foods Show all 10 1 /10 The exercise it takes to burn off high-calorie foods The exercise it takes to burn off high-calorie foods Sugary soft drink - 330ml - 138 calories Walk off: 26 minutes. Run off: 13 minutes. JOEL SAGET/AFP/Getty Images The exercise it takes to burn off high-calorie foods Standard chocolate bar - 229 calories Walk off: 42 minutes. Run off: 22 minutes. Koichi Kamoshida/Getty Images The exercise it takes to burn off high-calorie foods Chicken and bacon sandwich - 445 calories Walk off: 1 hour 22 minutes. Run off: 42 minutes. Justin Sullivan/Getty Images The exercise it takes to burn off high-calorie foods One quarter of a large pizza (449kcal) Walk off: 1 hour 23 minutes. Run off: 43 minutes. Getty Images The exercise it takes to burn off high-calorie foods Medium mocha coffee - 290kcal calories Walk off: 53 minutes. Run off: 28 minutes. Getty Images The exercise it takes to burn off high-calorie foods Packet of crisps - 171 calories Walk off: 31 minutes. Run off: 16 minutes. Evan-Amos/Creative Commons The exercise it takes to burn off high-calorie foods Dry roasted peanuts - 50g - 296kcal Walk off: 54 minutes. Run off: 28 minutes. Getty Images The exercise it takes to burn off high-calorie foods Iced cinnamon roll - 420 calories Walk off: 31 minutes. Run off: 16 minutes. Justin Sullivan/Getty Images The exercise it takes to burn off high-calorie foods One bowl of cereal - 172 calories Walk off: 31 minutes. Run off: 16 minutes. Getty Images The exercise it takes to burn off high-calorie foods Blueberry muffin - 265 calories Walk off: 48 minutes. Run off: 25 minutes. Isabelle Hurbain-Palatin/Creative Commons

And this is what her workout involves:

Bench-pressing 70 pounds, machine leg curls and leg presses, chest flies and lat pull-downs, one-legged squats, full push-ups, planks and squats with 12-pound dumbbell curls, amongst other cardio and exercises.

It’s an insane-sounding workout that would be challenging for a lot of people a quarter of Ginsburg’s age, and apparently she barely rests between exercises too.

When asked by Politico whether he thought US President Trump - who famously does little more exercise than golf - could complete Ginsburg’s workout, Johnson perhaps wisely declined to comment.