How to upgrade the wall sit: The high school gym staple that’s been firing up your glutes since 9th grade

Remember high school gym? The itchy uniforms that you washed, like, once every three months? The grueling pacer test? The kickball championships that ended in tears? Yeah, I can’t say I’m all that nostalgic for my days of state-mandated physical education either, but there is one #TBT move that does deserve room in your adult workout regimen: the wall sit.

“The wall sit is a great exercise to add towards the end of a lower body focused set of exercises. In other words, it’s a great way to burn out those muscles,”says Bojana Galic, a trainer at New Jersey’s Hoboken Fitness. “Let’s say your set consists of lateral band walks, reverse lunges, and glute bridges—you can add a minute-long wall sit as the last exercise in the set to burn out your glutes, quads, and hamstrings.”

Before we talk about how you can modify the booty-burning, let’s talk form. Start by finding a wall at the gym (or wherever you get sweaty!) and sit down in that imaginary chair. “At all times, keep your back flat against the wall. Your hips and knees form a 90 degree angle, feet are flat on the ground, shoulder-width apart. Keep your core tight and arms at your sides,” says Galic. “Don’t let your hands wander to your knees to make the exercise easier!” (You’ve definitely graduated from that shortcut).

Once you’re comfortable holding the move statically for 60 seconds, you’re ready to step it up a notch. “There are a lot of ways to increase the difficulty of a wall sit,” Galic says. Option one? Add weights. “You can place a plate on your lap, hold dumbells at your sides, [or] place a resistance band above your knees,” she explains. To infuse a little creativity into the old school move, you can also try a single-leg option, with one foot pointing straight in front of you.

“As you make the exercise more difficult, however, it’s key to keep the form correct,” says Galic. After all, you wouldn’t want your gym coach to appear out of the ether to make you run laps.

While we’re talking lower-body moves, here’s the right way to do a squat and why you definitely need a banded jump rope.