Flat Ab Hacks, and Other Lies

I spend a portion of my time each week reading articles, reviewing educational resources and even taking online trainings with respected fitness professionals. But every so often something leads me down a rabbit hole that gives me a glimpse into how much misinformation still exists in the world of fitness. Most recently, I was sucked into the vortex of lies surrounding flat, chiseled, sculpted, sexy abs.


I could point to an overwhelming number of examples of misleading YouTube Stars and Instagram Influencers selling the lies of a 6 pack in 2 weeks if you follow their 20 minute program everyday. Some even promise you’ll lose belly fat by doing a targeted ab workout despite the scientific evidence that proves otherwise. Don’t feel badly if you’ve believed this sort of thing, by the way. There is so much of this misinformation constantly being thrown at us that it would be hard not to wonder about it, and buy into it if you didn’t know better.

But even I was shocked as my spiral down the sexy abs rabbit hole revealed an apparent “hack” to get a smaller waist line and flatter belly that’s trending now: the “Stomach Vacuum”. Wait… what?! Do they mean my beloved Diaphragm Vacuum?

My students and gym members all know how much I love and promote the Diaphragm Vacuum. This ancient yogic practice known as Uddiyana Bandha in Sanskrit has a host of amazing benefits for those who regularly perform it:

  • It strengthens, stretches and restores proper functioning to the respiratory diaphragm

  • Because the diaphragm is the primary breathing muscle, more strength and suppleness will allow for better respiratory health

  • The diaphragm connects to the ribcage and lumbar spine, and shares fascial connections with the quadratus lumborum, psoas and transversus abdominus, so improved functioning of the diaphragm can help with better posture, reduced back pain and greater core strength

  • Diaphragm vacuums improve circulation in the abdominal viscera and aid in digestion and elimination

  • Better breath mechanics and diaphragm health allow a greater ability to tap into relaxation, and a parasympathetic nervous system response

Honestly, because of the breath’s ability to impact our physical, mental and emotional states, and the location of the diaphragm in the body we could almost argue that just about anything could be improved by having a stronger and more supple respiratory diaphragm. Hold on a second – what about a smaller waist and flatter belly?!


OK, if you picture the “core” as a canister, you have the pelvic floor muscles on the bottom of the canister, the diaphragm on top, and all abdominal and back muscles in between. So, yes, a strong core needs a strong diaphragm, and it should be included in core training. But changing the appearance of any area of your body involves using your entire body in an intelligently designed program, as well as changes in nutrition.

So how did the magical Diaphragm Vacuum get dehydrated, ripped and shredded into the “Stomach Vacuum” anyway? Here’s my best guess from what I’ve been able to piece together: “Golden Era” 1970s Bodybuilders like Arnold Swartzenegger would often make an impressive pose of a spread rib cage, with the abdominal muscles contracted and pulling in to create the appearance of a large chest and small waist called the “Stomach Vacuum”. It appears it was borrowed from the yogic practice of Uddiyana Bandha, as many yoga poses and ideas find their way into the fitness world.

Unfortunately contracting the abdominal muscles during the Vacuum, actually inhibits the Vacuum from happening! Now, I don’t know how Arnold and other bodybuilders of his era actually practiced the Vacuum. It’s possible they practiced it properly, and then used this modified engaged abdominal version for impressive looking posing. In my searching down the rabbit hole, I was more interested in what’s happening now with this trend, and I found a Cosmopolitan article from last month entitled “Vacuuming Your Stomach is a Thing, and Here’s How it Works”.

First I’ll tell you how it actually works, then how they “think” it works. A quick word of caution before you try it- Diaphragm Vacuum should be practiced on an empty stomach (at least 2 hours after eating), should be avoided if you have ulcers or hernias, and should be entered into very gently by those with high blood pressure. The Vacuum can be practiced in a variety of postures, but supine (on your back) with feet planted is a good way to start:

  1. Take an abdominal thoracic breath in. This is a big inhalation that inflates not just the belly, but the chest as well.

  2. Exhale all of your air out. This will likely require some abdominal engagement to exhale fully.

  3. Release tension in your abdominal muscles, as you elevate and expand your ribcage as much as possible WITHOUT TAKING AIR IN. You’ll feel the external intercostals (muscles in between the ribs) activating to allow this action.

  4. If you’ve done this correctly you should feel a suction (vacuum) in your throat and ribcage area as the diaphragm stretches maximally up into the ribcage, pulling along with it the abdominal muscles and organs.

  5. The vacuum occurs in the pause between exhalation and the next inhalation. Over time, you’ll develop your ability to stay in the vacuum for longer durations. When you need to take your next inhale, release the diaphragm and the throat gently first.

It does take some practice to understand the DV, and even longer to get comfortable “vacationing” in the pause between breaths for any length of time. This is why it’s best practiced when you are in a fairly relaxed state to start with, hopefully with a really good understanding of diaphragmatic breathing, and in easy postures like on your back. It can also be tricky to navigate letting go of tension in the abdominal muscles. It would seem like “sucking in” would help hollow out the belly more, but the fiber connection of the transverse abdominus to the diaphragm means tension in the TA will prevent the diaphragm from maximally stretching and being vacuumed up into the ribcage. It’s also a little scary for many of us, whether consciously or unconsciously, to actually let our bellies be soft. Why? Maybe Cosmo has the answer?


The Cosmopolitan article does include a couple of things that are true: they do admit the “Stomach Vacuum” will not actually give you flat abs, and they mention that performing this move could help with posture and back pain… but even that is unlikely when doing the move as they describe it. The article calls the move a breathing exercise which is absolutely true, but do you want to guess how many times they mention the diaphragm? Not once. Nor the word ribcage.

Instead they say the point is to activate the transverse abdominus (which we know actually prevents the vacuum), that the move is a cousin of the plank (absolutely not), and suggests pulling the navel to the spine will strengthen the core (advice long ago replaced with better cueing by PTs and true fitness professionals). They describe how to perform the move, advocating as intense a contraction as possible, and taking small breaths while holding it… So not only would someone practicing this not get any of the real benefits of a Diaphragm Vacuum, they wouldn’t really be getting any real core strengthening either. So once I again, I wonder why?

In all fairness to Cosmo, they weren’t the only source I found presenting the “Stomach Vacuum” with similar instructions, and the disclaimer that while of course this move alone won’t shrink your waist line and give you flat abs, it can help you get there. So why not teach a real diaphragm vacuum? Or real core strengthening that teaches integrating the whole core – working pelvic floor to diaphragm and everything in between? Well, it can be complicated, and confusing, and take some time to develop skill and understanding. I get all that. But I think it goes deeper than that. And honestly deeper than I can expound on in this brief article.

What I will say is this: I’ve worked with people who were so obsessed with flat abs and a “ripped” midsection that they had a hard time retraining their bodies to breathe full breaths. People who have been so trained to “suck in” they’ve had digestive problems, and felt anxiety and difficulty relaxing. I’ve worked with people (usually younger ladies) who have told me they don’t care about what their bodies can do or how they feel, as long as they look a certain way. If those things don’t make you kind of sad, or at least shake your head, they should.

Does that mean you shouldn’t want to have defined and strong abs? Of course not! But “chronically tight” muscles anywhere in the body will cause an imbalance and problems somewhere else in the body, and the abs are no exception. Please remember that what the mainstream fitness industry sells is the fantasy of an unrealistic image, and that if it sounds too good to be true – even with a disclaimer – it probably is. And if they call it a “hack” and promise it in two weeks, use your powerful legs to run far, far away.

Strength & Love,


PS – I'll be posting a video demonstrating how to do the DV, and one of my favorite advanced variations on my Instagram in a few days, so make sure you are following me @katiterray

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