Ruth Bader Ginsburg's trainer: 3 bodyweight exercises that 'cover it all,' for your home workout - CNBC

U.S. Supreme Court Justice Ruth Bader Ginsburg is serious about her workouts. Since 1999, she's worked out with the same personal trainer, Bryant Johnson.

One habit that Johnson says is key to the 87-year-old's health? Strength training.

Ginsburg's hour-long workouts with Johnson include a mix of cardio and bodyweight only strength-training exercises, Johnson told CNBC Make It in 2018. Some of her go-to exercises include planks, push-ups, chest and shoulder presses, bicep and leg curls, one-legged squats and knee raises, he said.

"You can do weight-bearing exercises at home," Johnson told a blog for skincare company Pause, which is good news for anyone whose gym is closed during the pandemic. And you can use household items in place of weights: a gallon of water weighs about eight pounds, for example, while a 16-ounce bottle of water weighs around 2.5 pounds.

But any weight-bearing exercises (think: squats, lunges and push ups) count as strength-training, Johnson said. "Be creative. There are many exercises you can find online that use just your bodyweight."

Research suggests that strength-training has lots of health benefits, including increasing muscle mass, strengthening bones, boosting heart health and burning body fat.

Beyond muscle strength and physical fitness, lifting weights can also impact your longevity. A 2015 study found that people who lift weights live longer; those who lifted twice a week had a 46% less risk of early death than those who didn't.

"My report card for Justice Ginsburg came back when she visited her doctor in her 70s and her bone density had gone up," Johnson said. "The doctor said he had never seen that happen to a person of that age. Whatever you're doing, the doctor said, keep it up."

There are three strength-training exercises that "cover it all" in your workout, Johnson said. Here's how to do this RBG-approved workout at home:

Squat

How to: "Many will say, 'I can't do a squat,'" Johnson told Pause. "Sit on a chair or bench and hold three-pound weights. Sit down and stand up. That's a squat."

Work your way up to doing a squat without a chair or bench; lower down until your thighs are parallel with the floor. Keep your chest lifted throughout the movement, and engage your abdominal muscles.

If you don't have weights, you can use water bottles or cans.

Push-up

How to: Lie face-down with your legs extended behind you. Place your hands flat on the floor beside your shoulders. Push your body up off of the floor until your arms are fully extended and you're in a plank. Slowly lower to the starting position.

"If you're a beginner, you start with things like wall pushups, and then build to doing pushups on your knees, then to doing pushups off your knees," Johnson told Pause.