What Does ‘Activate Your Core’ Even Mean?

If you’ve spent any time in fitness classes, personal training, or even browsing workouts online, you know that sometimes fitness lingo can sound like just a string of random, meaningless words or syllables. Like AMRAP (“as many reps/rounds as possible” in a set amount of time), or EMOM (starting a new move “every minute on the minute”), or “engage your [insert body part that you’re not quite sure how to engage here].” It’s a lot. While some people are fluent in fitness-speak, there are just as many if not more who are wondering WTF is going on.

Even as a fitness writer and certified trainer, I can see how a lot of the acronyms and cues that trainers use over and over again can sound a little confusing—especially when you hear it in a crowded class or workout video where you can’t exactly ask for clarification.

One of the best examples of this is the direction to “activate your core.” I’d make a bet that you’ve heard an instructor say it in a group fitness class, or read it in an online workout description. Trainers are always asking—begging, really—for us to activate and engage our core. But unless you’ve worked with a trainer one-on-one or are a very experienced exerciser, it’s likely you’re still trying to figure out what “activating” truly means, what it should feel like, and why it’s such a vital part of any move.

For all its vague terminology, activating your core is actually an important cue for anyone working out to understand. So here’s what you need to know to master it—and make the most out of any exercise.

What does it really mean to “activate” your core?

Before you can learn how to activate your core, you first need to understand what your core actually is. Spoiler: It’s way more than just your abdominal muscles.

There’s not one ultimate agreed-upon anatomical definition, but most contemporary researchers consider the core the lumbopelvic hip complex, says Susan F. Saliba, Ph.D., P.T., director of the undergraduate kinesiology major at the University of Virginia and codirector of the Exercise and Sports Injury Laboratory (EaSIL) for musculoskeletal injury research. So, by that definition, it includes everything from your lower back to your abs to your deep abdominal wall, hips, glutes, and pelvic floor.

Now, onto the directive. The word “activate” really just means engage, or use. Essentially, you want to squeeze all of the muscles in your torso that you can, and hold them in that tightened position, all while still breathing normally. (That means not clenching them for dear life so that you can’t move or breathe.)

Not surprisingly, it’s a really difficult concept for many people to grasp at first. “When you say ‘pull your belly button in toward your spine,’ some people really suck in,” Kira Stokes, certified personal trainer and creator of the Kira Stokes Fit app, tells SELF. “It should be more of a sensation of tightening the muscles in your abdomen and your glutes.”

It also may help to think about it this way: Your core is what keeps your body stable as you do any sort of movement or exercise. Activating it, or engaging it, means having the muscles contracted enough so that if someone were to come over and try to push you over, your core would resist them and help you stay upright. (Maybe you’ve even had an instructor walk around and give you a little nudge during a group fitness class to check if your body is stabilized.)

Activating your core actually makes your workout safer and more effective.

Simply put, the core is the center of all your movement, says Stokes. “Planks, crunches, and other abs exercises make it obvious you’re working on core strength—you feel the burn. But in any movement that you do, bodyweight or weighted, your core is used in terms of strength but also stabilization,” she explains. Your core muscles are what allow you to rotate, resist rotation, stabilize your torso, maintain good posture, and keep your balance.

By activating and using your core so it does all of these movements properly, you’ll be able to move more efficiently and effectively, Femi Betiku, D.P.T., C.S.C.S., Club Pilates instructor in New York, tells SELF. That also ultimately means a lower risk of injury.

One reason? It’ll help keep your lower back in a safe position. Squeezing your glutes in particular will give you a slight posterior pelvic tilt, which just means your pelvis is tucked under a tad, so that your lower back is in a neutral position, says Stokes. (If you don’t engage your core, you can revert to a more anterior pelvic tilt, where your butt’s popped out and your back is arched, which ultimately puts a lot of pressure on the lower back.)

Engaging your core also helps you cut down on over-relying on other muscles to get the power you need to crush each exercise.

“When you’re using your core along with arms or legs or both, you’re able to use the least amount of force for maximum impact,” Betiku says.

It’s a lesson Betiku recently taught one of his clients, a soccer player recovering from a hip strain. Because she was not activating her core when she kicked, her hip flexors were taking on all that work, leading to overuse. Once he taught her to fire her core, she was able to cut her reliance on her hip flexors, reduce the strain to them, and kick a soccer ball with more power.

But you don’t have to play sports to reap that benefit: The concept applies to pretty much any movement. When you’re doing a lunge, if you engage your core, you’ll take some of the work off your legs, helping you move more efficiently, do more reps, and maybe even lift heavier too. During bent-over rows, an engaged core will keep your torso from rotating in a way that tweaks your back. Same thing for deadlifts, squats—you get the picture. You’ll still primarily work the muscle you’re targeting, but your core will do the other work that needs to be done so that other muscles don’t end up overcompensating.

Here’s how to know if you’re activating your core properly.

Okay, so you know why firing your core is important, but that doesn’t mean a whole lot unless you can recognize what it should feel like so you can determine whether you’re doing it right. To do that, you can try a few different drills.

Stokes suggests lying on your back with your knees above your hips in tabletop position. In this position, squeeze your glutes and your core muscles so that your lower back presses into the floor. Aim to be as flush with the floor as possible, though your back’s natural arch may prevent it from pressing down completely. (It’s easiest to feel core “activation” when lying on your back, Saliba notes, because you can use the floor for feedback.)

From here, place your palms on your quads and try to push them forward and toward your feet as you simultaneously resist the tension using your entire core. If neither your legs nor arms move at all despite your pushing, your core is activated.

Another option is to get into tabletop position, but instead of pressing against your legs, simply extend one leg out straight, Betiku says. As you do it, use your glutes and abs to keep your lower back from lifting off the ground—the goal is for your torso to stay completely still.

Doing one of these drills first will help you better transfer the concept to standing and sitting positions. Then, once you know what “activating your core” feels like, you should make it a point to fire it up before you do any exercise, whether it’s an abs move or not. When you do any other exercise, you should feel some muscle activity in your midsection—meaning, you should feel all of those muscles contracting and working, even if they’re not working to the same extent of the muscle you’re targeting, Betiku says.

And remember that putting your brain into your movement can go a long way. The more you think about engaging your core, and really focus on how it feels, the more muscle awareness you’ll develop and the easier it will become, Betiku says.

It’s something you’ll always have to keep in the back of your mind, but with practice, it’ll become second nature for you to do. “Eventually, once you understand the feeling, you’ll be able to feel yourself drifting out of it because you’re so in tune with your body,” says Stokes. “But you always want to think of minding your muscle, not just passing through movement.” That one simple thought can truly make a total-body difference.