Whether you’re walking, running, climbing stairs, or picking something up off the floor, your butt muscles are firing. And this Pilates glute workout will zero in on that all-important area—including the tiny muscles that often get overlooked in traditional strength training.

The third installment of Sweat With SELF’s new Pilates series is all about glute strengthening and stabilization. Sina Riemann, a certified personal trainer and Pilates instructor based in New York City, will take you through a 20-minute workout designed to challenge not only the biggest muscle in your butt—your gluteus max—but also the smaller ones along the sides of your seat, your gluteus minimus and medius. These tiny side-butt muscles keep you steady while you move and help prevent other parts of your body (say, your lower back) from swooping in to get the job done.

You’ll begin with a dynamic warm-up, which is packed with exercises you’ll probably recognize (like the bodyweight squat) and some that may be new to you (like the standing knee-opener); this series is designed to get the blood flowing in your quads, hamstrings, and butt, as well as your core, to help prep those areas for the work ahead.

You’ll be doing a lot of single-leg work in the actual routine—that’s key because your side-butt muscles have to really fire to keep you from wobbling. You’ll cycle through moves like the static curtsy lunge (there will be pulses here, because, well, Pilates), donkey kick (again, you’ll be pulsing), side-lying leg sweep, and clamshell. These exercises have you moving in both the sagittal plane of motion (up and down, like with the donkey kick) as well as the frontal plane (side-to-side, like with the curtsy lunge). A lot of folks often neglect lateral movement with strength training, so their side-butt muscles don’t get the challenge they need to get stronger and more stable.

While you’ll be using just your bodyweight, the programming—lots of time under tension without much rest—is pretty intense. So don’t hesitate to take a breather if you need it. This routine is all about finding your challenge.

With that, if you’re ready to hit your entire butt, fire up this Pilates glute workout and get ready to work! (Already looking to your next routine? Give this Pilates hip mobility workout a try next.)

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