We Tried It: Working Out With Ruth Bader Ginsburg’s Trainer (and Barely Survived)

What It Is: A workout class with Ruth Bader Ginsburg‘s trainer, Bryant Johnson

Who Tried It: Diana Pearl, PEOPLE.com writer/reporter

Level of Difficulty: 8/10. This was definitely an intense workout that had me sweating and longing for a break, but it didn’t actually kill me

I don’t pretend to be a fitness junkie or even a fitness fan. I’ve pushed myself to work out once a week, occasionally twice, if I’m feeling especially motivated. And when I’m at the gym, I’m always looking at the clock to see how much longer I have to sit through a class or self-imposed time limit before I can peace out.

Supreme Court Justice Ruth Bader Ginsburg, on the other hand, is a fitness junkie. Since 1999, she’s worked out two times a week (Wednesday and Friday) with her personal trainer, Bryant Johnson, who has penned a book — The RBG Workout: How She Stays Strong…and You Can Too! — to give fans of the justice a chance to try out her grueling regime at home. The pair started working out together after she beat cancer for the first time and her husband wanted her to build up her physical strength.

I got to test it out for myself during a class with Johnson in N.Y.C., where he lead us through an abbreviated version of Ginsburg’s strength-training workout. (Our class was about 35 minutes, while she usually goes for about an hour.) We also took the class in N.Y.C., rather than Ginsburg’s preferred workout location of one of the two Supreme Court gyms. And instead of her preferred soundtrack of NPR or classical music, we had ’70s hits playing in the background.

I can’t lie, I was nervous going into it. Ginsburg may be 84, but everyone knows that she’s in great shape (and loves a good pushup.) Meanwhile, I can’t tell you the last time I did a pushup that wasn’t state-mandated for physical fitness testing in high school. I never use resistance bands — which were promptly handed out upon our arrival. And god help me if I have to hold a plank for longer than five seconds.

And hearing Johnson’s credentials only upped the butterflies: A military veteran and federal court clerk, he picked up training influential figures in the judicial branch (like Ginsburg) in the late ’90s as a “side hustle.” Now, he’s been working with RBG for almost 20 years and says she’s like family. (He also works with her fellow Supreme Court Justice, Elena Kagan.)

We started the workout with a warmup of jumping jacks and stretches, which were easy enough, before moving onto the tougher stuff: side planks, held for 15 seconds each, and then a 30-second plank, which, I won’t lie, I couldn’t hold the entire time. I’m not alone — Ginsburg doesn’t like planks, either.

We then broke out the resistance bands, first doing several rounds of chest flies. We later placed one end of the band beneath a foot, holding the other end with a hand and lifting it above your head, and then the middle of the band went underneath the foot while we squatted and pulled the band up.

All the while, I kept thinking to myself “Diana, an 84-year-old does this twice a week. YOU CAN DO IT.” But Ginsburg is no normal 84-year-old, and the workout was tough. When new moves were met with groans, Johnson just yelled out “This is what she does!” as if to serve as a reminder to the room of 20 and 30-somethings that if someone in their mid-80s can do it, we truly have no excuse.

And it was only getting harder: We then moved onto pushups, a Ginsburg signature. She’s known for her prowess at pushups, and doesn’t do them on her knees, but Johnson cut us some slack. We did a few traditional pushups, and then 5 more on our knees. Or at least, that’s what we were told to do. Looking around the room (and at myself), more than a few people cheated a bit.

When we made our way into a cool down, I realized that if this was Ginsburg’s workout, she’d only be just over halfway there. And with that, I truly gained a new level of respect for the longtime justice.

Verdict: Ginsburg and Johnson don’t mess around. To put it simply, the workout was really, really hard. Evidence? The next day, my stomach muscles hit a level of soreness I don’t know if I’d ever experienced before. (It honestly felt like someone had ripped apart my abdomen.) The RBG Workout: How She Stays Strong…and You Can Too! is definitely worth consulting if you want the stamina of “the justice,” as Johnson calls her.

And if I’m convinced of anything, it’s this: Ginsburg is likely rocking a six-pack underneath that robe.