The most common mistake to make when doing the side lunge

Nailing a move like the lunge can make you feel like a rockstar. By simply stepping forwards or backwards, you can work your quads, hamstrings, calves, and glutes all at once—the perfect addition to a leg day workout, with endless variations. You can even do it with weights, incorporating bicep or hammer curls as you lunge back. And then there are Swan Lake-style ballerina lunges, that whole lunge-around-the-clock sequence from Ariana Grande’s trainer, and—a basic but highly beneficial upgrade—side lunge.

Side lunges are ideal because they take the typical forward-and-back movement to a lateral level, which then works your butt even more. (Yes, please.) The thing is, while they look simple—you just side-step and bend, right?—there are easy mistakes to make.

Take it from Obé fitness trainer Megan Roup, who happens to be leading our Well+Good Retreat in Miami later this month. “I see this a lot in class—it’s a simple mistake, but you’ll see a lot of people not shifting their weight onto that working leg,” she says. “There’s a little bit of a hip swivel.”

Essentially, you’re supposed to keep your weight balanced, take your butt back—and lean into the leg that’s lunging out. “What I want to see is you tracking that working leg and shifting that weight back into the working heel as you come back up,” Roup explains. “Hinge forward with a neutral spine. It’s like your butt is being pulled back to that back wall. But most importantly, I’m tracking that working knee as you pick it back up.” And now you can work that peach like a pro.

For other killer workout moves, try the modified plank seal walk or these push-up variations.