What Trainers Really Mean When They Tell You to 'Engage Your Core'

Picture it: You're in the middle of a plank during a HIIT workout, or holding chair pose in yoga class, or doing just about any other fitness move you can imagine when an instructor yells out those three powerful words—''Engage your core!'

You hear the phrase, sure; and you may even try to flex your abs—but do you really know what it means when a trainer tells you to engage your core, and how to do it the right way to get the most out of your workout?

Here, three fitness experts weigh in on the ubiquitous-yet-confusing topic of core engagement: What it really means, how to do it properly, and what benefits you get from bracing your midsection during a workout.

You can think of core engagement as contracting the appropriate muscles in your midsection so that you create enough stiffness to adequately support your spine and pelvis, Laura Miranda, PT, DPT, CSCS, a physical therapist and certified strength and conditioning specialist, tells Health. The goal of core engagement, Miranda explains, is to prevent excessive motion at the spine and the pelvis when force is placed on your body, which happens when you perform pretty much any activity—from walking, running, and jumping to bending, squatting, and picking up a child.

Core engagement is "really a feeling of being stable," DeAnne Davis Brooks, Ed.D, a certified exercise physiologist, associate professor in the department of kinesiology at the University of North Carolina Greensboro, and USATF Level 1-track coach, tells Health. But this stability doesn't come from just contracting your abs or "sucking in" your stomach (which is what most people think when they hear "core").

In truth, your core encompasses everything on the front and backside of your body from your rib cage down to the bottom of your butt, says Brooks. That includes 29 different muscles; some, like the transverse abdominis (a large muscle that wraps around your spine and sides), are buried deep in your body, while others, like the rectus abdominis (your "six-pack" muscles), lie close to the surface.

Now, you don't have to contract all 29 muscles simultaneously. Which core muscles you use depends on what activity you're doing. The set of core muscles you use to jump rope, for example, is going to be a little different than the set of core muscles you use to perform a deadlift.

As a baseline though, effective core engagement is about specifically contracting the deep stabilizing muscles, which include the transverse abdominis, the diaphragm, the pelvic floor, and the multifidus (a thin muscle that lines your spine). These muscle groups need to be engaging and disengaging at the appropriate times in order for the core to be maximally stabilized, Marissa T. Schaeffer, PT, DPT, CSCS, owner of Marissa T Schaeffer Physical Therapy, tells Health. Good posture is also key to core engagement, adds Schaeffer, as that alignment improves your chances of tapping the correct muscles.

RELATED: What Is an AMRAP Workout? Why Trainers Love This Exercise Format—And 3 Routines to Try at Home

Still, good core engagement can be fatiguing, says Brooks—both because of the coordination as well as the muscular endurance it demands. So if you feel like you're engaging your core correctly and become tired as a result, that's a-ok. True core engagement isn't easy and it will take some time to build up to if you're not used to it.

RELATED: EMOM Workouts Can Really Up Your Training—Here Are 2 Trainer-Approved Routines to Try

What are the benefits of engaging your core?

We've established what core engagement is and what it should feel like, but, um, why does it even matter? For one, good core engagement serves as a stable foundation for really anything you do in life. "No matter what exercise you're doing, the core is a fundamental component," explains Miranda.

The deep stabilization system of the core "is there to support your skeleton," says Schaeffer. And when that deep stabilization system is properly activated, you'll be able to perform both exercises and everyday tasks efficiently and without unnecessary motion. For example, with good core engagement, you'll likely be able to carry a bag of groceries without twisting your spine or perform overhead dumbbell presses without moving your legs. Good core engagement may also reduce your risk of injury; a 2017 review in Physical Therapy in Sport found an association between impaired core stability and lower-body injuries in otherwise healthy athletes.

Core engagement can also increase the strength and coordination with which you're able to perform movements that involve muscle groups outside of the core, says Brooks. For example, proper core engagement can help you jump higher or possibly squat with more weight, says Schaeffer.

RELATED: What Is Tendinitis? Experts Explain This Painful Condition

How to engage your core

These beginner moves all involve engaging your core without actually moving your midsection. As Miranda explains, you need to master engaging your core muscles without any movement so that you can then master engaging your core muscles with movement (as you would in a variety of sports and life activities). These moves also all incorporate diaphragmatic breathing (a technique where your breath fills the abdomen instead of the chest), which Miranda says is an important part of good core engagement.

If you're brand new to core work, you'll want to do these moves pretty regularly so that you can build your core engaging abilities. And if these feel familiar to you? It's still a good idea to incorporate them into your routine, even if just for a few minutes; they work great as a warm-up before strength workouts, says Miranda. "Every athlete, every person—newbie to advanced—needs to do this stuff," she explains.

Anti-extension leg lifts

The goal of this move is to have strong enough core engagement so that you prevent your spine from extending.

• Affix a light resistance band to a stable object, like the leg of a table
• Lay on your back next to the resistance band. Bend your knees and make sure your pelvis is neutral (i.e., not tipped to one side).
• Inhale and allow air to fill your stomach. Purse your lips, exhale forcefully, and drop your ribs down. As you exhale, press your fingers into your stomach and notice if it tightens—it should, if you're doing this correctly. (If you don't feel anything, imagine a child is about to jump on your stomach; that should cue your muscles to tighten.) Keep exhaling until you've blown all the air out of your stomach.
• Repeat for three to five breaths. Try to maintain tension in your core even as you inhale.
• From here, raise your arms straight up over your shoulders and lift your legs up with hips and knees bent to 90-degree angles.
• Grab the resistance band (it should be positioned at about head height) and hold the band with both hands. Position yourself far enough away from the band so that there is no slack, but close enough that you can keep the band positioned directly above your shoulders. From here, continue the above pattern of breathing in through your stomach and then exhaling and contracting your core. Make sure your pelvis isn't tilting side to side and your back isn't arching.
• When you've mastered that, inhale and then exhale as you brace your core and slowly lower your right leg down to the ground over the course of three to four seconds. Tap your heel on the floor and then inhale and slowly reverse the movement over three to four seconds. Make sure your ribcage stays down and your pelvis doesn't rotate side to side.
• Repeat with your left leg. That's one rep.
• Perform 8 to 10 reps (or as many as you can with good form). If you can do more than 10 reps with good form, make the move more challenging by using a heavier resistance band or by straightening your legs in the leg taps.

Anti-Flexion Standing March

The goal of this move is to have strong enough core engagement so that you prevent your body from bending to the side.

• Stand up tall with your ribcage down and your hips, ribcage, and shoulders stacked.
• Exhale, contract your core, and then, over the course of 3 to 4 seconds, drive your right knee up to waist level as you flex your right ankle and swing your left arm.
• Make sure your ribs stay down, your back doesn't arch, and your torso doesn't tip to the side.
• Pause when your knee reaches waist level and then inhale and slowly reverse the movement.
• Repeat with your left side. That's one rep.
• Do 8 to 10 reps or as many as you can do with good form. If 8 to 10 reps feels easy, do the move with a light mini band around your feet. If that feels easy, hold dumbbells or weights.

Anti-rotation Paloff press

The goal of this move is to have strong enough core engagement so that you prevent your body from rotating. (Tip: Most people will incorrectly try to muscle through this with the strengthen their arms, says Miranda. To prevent that, think of your hands as simply being a hook for the band and focus instead on maintaining tension in your core.)

• Affix a resistance band to a stable object so that it is at about shoulder height when you are kneeling on the ground.
• Get into a half-kneeling position and position yourself so that the band is to one side of your body, at shoulder height. Your ribcage is down and your knees, hips, and ribcage are stacked.
• Grab the band with both hands and bring your hands in front of your chest. Exhale and create tension in your core, squeeze the glute on the leg that is back, and slowly press the band away from your body, keeping it at chest level. Continue exhaling and bracing your core so that your body doesn't rotate toward the band.
• When you finish exhaling, pause and then slowly reverse the movement, keeping your elbows close to your rib cage and continuing to brace your core so that your body doesn't rotate toward the band.
• Do 5 to 8 reps (or as many as you can do with good form). Switch your stance so that your other leg is forward and do another 5 to 8 reps.
• Flip around so that the band is now on your other side and repeat.

To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter