FITBODY Exercise Library · Abs
Stomach Vacuum Exercise
Ditch the waist trainers. The stomach vacuum, also called the ab vacuum, is an isometric exercise for the deep core that teaches you to draw your midsection in rather than push it out, and it can be done anywhere with no equipment at all.
What Is the Stomach Vacuum Exercise?
The stomach vacuum, also known as the ab vacuum, is an isometric contraction exercise of the transversus abdominis, meaning you tense the muscle without moving it. You exhale fully, then draw your abdominal wall up and in toward your spine and hold.
Most women are familiar with sit ups and crunches as the way to work the abs, and they get frustrated when their waist measurement does not change. The stomach vacuum works a completely different muscle in a completely different way. Rather than flexing your spine, it trains the deep muscle that wraps around your midsection like a corset, and learning to engage it deliberately is a skill that carries into every other exercise you do.
How to Do the Stomach Vacuum
There are several ways to do stomach vacuums, and I prefer to start standing.
Do not expect to get this on the first try. This is a coordination skill more than a strength exercise, and almost every woman I teach it to feels ridiculous for the first week or two. The exhale is the part people rush. Get every bit of air out first, and the draw-in becomes much easier to find. Once it clicks, you can do it standing, kneeling, seated, or lying down, which means you can practice it anywhere.
What Muscles Does the Stomach Vacuum Work?
The transversus abdominis is the target, and it is the deepest of the abdominal muscles. It wraps horizontally around your midsection beneath the obliques and the rectus abdominis, which is why tightening it produces a cinching effect rather than a crunching one. Your obliques, diaphragm, and pelvic floor all participate in the hold. For a fuller picture of how these layers sit together, Cleveland Clinic has a good overview of the abdominal muscles.
See the full muscle breakdown
- Transversus abdominis: the deepest abdominal layer, running horizontally across the midsection. It is the muscle doing the drawing-in and the one this exercise exists to train.
- Internal and external obliques: assist with the hold and contribute to compressing the abdominal wall.
- Diaphragm: central to the movement, since the vacuum depends on a complete exhale and the position of the diaphragm afterward.
- Pelvic floor: works alongside the transversus abdominis as part of the deep core system rather than in isolation.
- Multifidus: the deep spinal stabilizers, which co-contract with the transversus abdominis to support the lower back.
Benefits of Stomach Vacuums
- Builds a real mind to muscle connection with the deep core. Properly contracting your core during harder ab work is difficult and takes practice. Isolating the region here teaches you a skill you can then use in every other exercise.
- Supports the lower back and posture. Strengthening the muscles that support your core and lower back, particularly the transversus abdominis, helps take pressure off your spinal column.
- Carries over into injury prevention. Knowing how to brace your deep core translates into everyday movements like twisting side to side or lifting overhead.
- Improves how your midsection holds itself. Because the transversus abdominis wraps your midsection, training it to hold up and in gives a cinching effect and the appearance of a tighter waist.
Do Stomach Vacuums Actually Shrink Your Waist?
To a point, and it is worth understanding the mechanism so your expectations match reality.
Stomach vacuums do not burn fat. Nothing you do with one specific muscle reduces the fat sitting on top of it. What they can do is improve the resting tone and control of the muscle that wraps your midsection, so your abdominal wall holds itself in rather than relaxing outward. That genuinely changes how your waist looks and can change a tape measure reading.
You will see claims about knocking inches off in a couple of weeks. Real change takes consistent practice paired with a solid nutrition plan, and the visible difference comes from the combination rather than from vacuums alone. If a tighter waist is the goal, the vacuum is one useful piece of a body recomposition approach, not a substitute for it. It is still a far better use of your time than a waist trainer.
Stomach Vacuums and Diastasis Recti
This deserves a careful answer, because the internet is confident about something the research does not actually support.
The common claim is that drawing-in exercises like the stomach vacuum close the abdominal separation that occurs after pregnancy, while crunches and sit ups make it worse. The evidence points the other way on both counts. Ultrasound studies measuring the gap between the abdominal muscles have found that drawing-in maneuvers do not reduce that distance, while curl-ups actually narrow it. A 2023 randomised controlled trial concluded that a program of head lifts and curl-ups does not worsen the separation and does increase abdominal muscle strength, and that women should not be discouraged from doing them.
That does not make the stomach vacuum useless for diastasis recti. Research from Lee and Hodges found that pre-activating the transversus abdominis before a curl-up produced a wider gap but a much less distorted linea alba, which may allow better force transfer across the abdominal wall. Deep core training has a legitimate place in rehabilitation. It just is not the gap-closing exercise it is usually sold as.
If you have diastasis recti, see a pelvic health physical therapist. This is a condition that benefits from an individual assessment, and a good pelvic PT will build you a program rather than handing you one exercise and a promise.
How Long to Hold and How Often
Stomach vacuums are programmed by hold time rather than reps, and they respond far better to daily practice than to occasional long sessions. This is a skill you are building.
| Stage | Rounds | Hold |
|---|---|---|
| Learning the movement | 3 to 5 | 5 to 10 seconds |
| Building control | 3 to 5 | 10 to 15 seconds |
| Advanced | 5 | 15 to 20 seconds |
Practice most days rather than a few times a week. Vacuums are easiest on an empty stomach, so first thing in the morning works well for a lot of women. Breathe shallowly through the hold rather than holding your breath, and stop the round when you can no longer maintain the draw rather than pushing to a count.
Variations and Modifications
Lying Stomach Vacuum
Start on your back with your knees bent and feet flat. Gravity assists the draw-in here, which makes it by far the easiest place to learn the movement. If you cannot find the vacuum standing, start here for a week or two.
Kneeling Stomach Vacuum
On all fours or upright on your knees. The quadruped position lets your abdominal wall hang, which gives you very clear feedback on whether you are actually drawing in. A useful middle step between lying and standing.
Seated Stomach Vacuum
Sit tall on a bench or chair with your feet flat. Removing the standing balance element lets you focus entirely on the breath and the draw, and it means you can practice at a desk without anyone noticing.
Standing Stomach Vacuum
The hardest of the four and the one I use most. Without gravity or a support surface helping you, your deep core does all the work. Build to this rather than starting here.
Where Did the Stomach Vacuum Come From?
The exact origins are not known, but the ab vacuum was widely used in the early days of bodybuilding by athletes known for a dramatic V taper and narrow waist. Physique competitors have used it for decades to train and display the midsection, and today athletes and fitness models chasing an hourglass shape have largely moved to vacuums instead of waist trainers.
Common Mistakes to Avoid
- Holding your breath. The vacuum is a hold, not a breath hold. Take shallow breaths throughout, because if you are locking your breath down you are bracing rather than drawing in.
- Not exhaling completely first. A partial exhale leaves air in your lungs and makes the draw-in almost impossible to find. Push everything out before you pull in.
- Pushing out instead of drawing in. Many women brace outward out of habit, which is the opposite movement. Think about pulling your navel up toward your ribs and back toward your spine.
- Hard tucking of the pelvis. Keep your pelvis neutral. Aggressively tucking the tailbone under changes the position of your spine and makes the draw harder rather than easier.
- Practicing occasionally. This is a skill. A few minutes most days will get you there far faster than one long session a week.
Stomach Vacuum FAQs
What is the stomach vacuum exercise?
The stomach vacuum, also called the ab vacuum, is an isometric exercise for the transversus abdominis, the deepest abdominal muscle. You exhale fully, then draw your abdominal wall up and in toward your spine and hold that contraction for several seconds while breathing shallowly. Nothing visibly moves, which is what makes it different from crunches or sit ups. It needs no equipment and can be done standing, kneeling, seated, or lying down.
What muscles do stomach vacuums work?
The transversus abdominis is the primary target. It is the deepest abdominal layer, wrapping horizontally around your midsection beneath the obliques and the rectus abdominis, which is why training it produces a cinching effect rather than a crunching one. Your internal and external obliques assist with the hold, and your diaphragm and pelvic floor are both involved since the exercise depends on a full exhale. The multifidus deep spinal stabilizers co-contract to support the lower back.
Do stomach vacuums shrink your waist?
To a degree, but not by burning fat. Stomach vacuums improve the resting tone and control of the muscle that wraps your midsection, so your abdominal wall holds itself in rather than relaxing outward. That can genuinely change how your waist looks and can change a tape measure reading. What it will not do is reduce body fat, so claims about losing inches in a couple of weeks overstate it. Consistent practice paired with a solid nutrition plan is what produces a visible difference.
Do stomach vacuums heal diastasis recti?
The evidence does not support that claim, despite how often it is repeated. Ultrasound studies measuring the gap between the abdominal muscles have found that drawing-in maneuvers do not reduce that distance, while curl-ups actually narrow it. A 2023 randomised controlled trial found that head lifts and curl-ups do not worsen the separation and do increase abdominal strength, concluding that women should not be discouraged from doing them. Deep core training still has a role in rehabilitation, but if you have diastasis recti, see a pelvic health physical therapist for an individual assessment rather than relying on one exercise.
How long should you hold a stomach vacuum?
Start with 5 to 10 second holds for 3 to 5 rounds while you are learning the movement. As your control improves, build toward 10 to 15 seconds, and advanced practitioners can work up to 15 to 20 seconds for 5 rounds. Practice most days rather than a few times a week, since this is a coordination skill as much as a strength exercise. Vacuums are easiest on an empty stomach, so first thing in the morning suits many women.
Why are stomach vacuums so hard to do at first?
Because it is a coordination skill your body has probably never been asked to perform. Most people are used to bracing outward rather than drawing inward, so the movement feels backwards at first and it takes practice before it clicks. The exhale is usually the sticking point, since a partial exhale makes the draw-in almost impossible to find. Start lying on your back where gravity assists, get every bit of air out first, and give it a week or two of daily practice before you judge whether you can do it.
References
- Lee, Diane, and Paul W. Hodges. “Behavior of the Linea Alba During a Curl-up Task in Diastasis Rectus Abdominis: An Observational Study.” Journal of Orthopaedic and Sports Physical Therapy, vol. 46, no. 7, 2016, doi.org/10.2519/jospt.2016.6536. Found that pre-activating the transversus abdominis before a curl-up produced a wider inter-rectus distance but substantially less distortion of the linea alba.
- Skaug, Kristina L., et al. “Curl-up Exercises Improve Abdominal Muscle Strength Without Worsening Inter-recti Distance in Women with Diastasis Recti Abdominis Postpartum: A Randomised Controlled Trial.” Journal of Physiotherapy, vol. 69, no. 3, 2023, sciencedirect.com/science/article/pii/S1836955323000528. Concluded that head lifts and curl-ups do not worsen inter-recti distance and that parous women should not be discouraged from performing them.
- Cleveland Clinic. “Abdominal Muscles: Anatomy & Function.” my.clevelandclinic.org/health/body/21755-abdominal-muscles.
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