This article originally appeared in “Chicago Tribune.”

e all do it. It’s our first reaction when someone snaps our photo. It’s how we make peace with our side profile in the mirror, and for some of us, it’s just what we do. All. Day. Long.

I’m guessing most women would be shocked to know that the seemingly innocent act of sucking in your gut has a slew of consequences. I know I was. A little over a year ago, I took a course with renowned women’s health physical therapist Julie Wiebe on training the pelvic floor. Among the wealth of information Wiebe shared was one powerful nugget of truth: Sucking in your stomach can actually contribute to dysfunction in your core instead of build it.

Yep, and by dysfunction, I mean everything from weakened core muscles, to stress urinary incontinence, to diastasis recti (separation of your superficial abs). In fact, a constantly drawn-in tummy can contribute to the very belly pooch you’re trying to hide.

Of course, upon hearing this, I looked down at my own tummy. Was I sucking it in? I took a breath and watched my belly relax to its normal size. The bigger question: Was I ever NOT sucking it in?

Now I’m sure you’re wondering when I’m gonna get to the “how.” How is it that something so simple and common can be so bad? At some point, you may have even been told that sucking it in was a good thing. Bear with me, because you’re about to get a mini anatomy and physiology lesson.

It starts with breathing. Your body functions best when your diaphragm moves freely for each breath. When you inhale, your rib cage and belly expand. When you exhale, your belly recoils back in and pelvic floor (kegel muscles) and transverse abdominus muscles (deepest abdominal muscles) subtly contract. When you breathe like this on a regular basis, your deep core muscles work together in a balanced way to help give you stability for movement, control your continence system and keep your pelvic organs where they belong. It’s a pretty miraculous thing.

When you suck in your stomach, you restrict your diaphragm’s ability to move well for an optimal inhale. Go ahead and try: Inhale, and you’ll notice your belly either doesn’t move or draws in even more, and your chest and shoulders rise. Exhale and your shoulders drop. The entire time, your deep core muscles have not had a chance to relax. Without relaxing, they can’t fully contract, so they are not really engaging, either.

This is no good for your core because your deep core muscles work with our pressure system. Hold your breath, suck in your stomach or constantly squeeze your pelvic floor muscles, and pressure builds up somewhere where it shouldn’t. Enter incontinence, diastasis recti, lower back pain, pelvic pain, pelvic organ prolapse, etc. The only best way to get your internal pressure system back in order, and your core muscles working properly is to relax your belly and breathe!

Other awesome things that happen when you breathe with your diaphragm include improved digestion (freely moving diaphragm massages your organs – win!), increased oxygen to your muscles and a better response to stress.

When Wiebe explained all of this during her course, it made so much sense. But I couldn’t believe it was the first time I was hearing it. I went home and Googled “suck in stomach affects pelvic floor,” and found that this was pretty common knowledge in the world of women’s health physical therapy. But then why had this information never made the cover of Women’s Health?

My guess is it would cancel out every picture of a model sucking in her stomach, every ad for Spanx (which basically force you to suck it in) and every article promising to score you a flat stomach. Because the reality is, unless you’ve just woken up, have pooped and haven’t eaten breakfast yet, your stomach’s probably not going to be totally flat. It shouldn’t be.

You may find that your habit of sucking in your stomach is hard to break. I’m going to share some tips that have helped me personally.

When you have a calm moment (lying in bed at night, sitting at your desk, etc), practice breathing with your diaphragm. Place one hand on the side of your rib cage and inhale through your nose. You should feel your ribs press out against your hand. Your chest should not rise. Exhale through your mouth. You should feel your belly draw inward. Take the opportunity to intentionally connect with your breath whenever you can.

Check your alignment. If your butt is tucked under you or your rib cage is lifted and spread open, you’ll notice it’s hard to breathe well with your diaphragm. Keeping neutral alignment, with your ribs directly over your hips and tailbone untucked, will help you breathe better.

Ditch clothing that makes you so self-conscious that you feel the urge to suck in your gut. I hate wearing super-fitted clothes to parties because I like to eat. When I eat, my tummy happily expands, but subconsciously (and maybe consciously, too), I’m not comfortable enough to just let it hang out. That is, unless nobody can tell. Enter the empire waist dress.

Use your workouts to practice good breathing habits – and also strengthen your deep core muscles. Prepare for a challenging movement – for example, an overhead press – by exhaling right before you start to lift the weights overheard to trigger the recoil or the deep core, continue to exhale through this movement, and then inhaling to ease the system as you lower the weights to the starting position.

And finally, get over it! You’re a real, breathing person – not a mannequin or a model in a magazine. Eat, breathe, take up space and apologize to no one.

Nicole Radziszewski is a freelance columnist. She lives in River Forest and is a certified personal trainer and mother of two. Check Nicole out on Facebook at Facebook.com/mamasgottamove.