Mythbuster
You have to actively 'pull the abs inward' on every exercise (vacuum/bracing confusion).
Summary
Permanently pulling the belly in (hollowing) is not the optimal trunk strategy under load – bracing (tensing outward) provides more stability for the lumbar spine. The evidence from Grenier & McGill (2007) shows that the activation strategy measurably influences stability.
Mythbuster: You have to actively 'pull the abs inward' on every exercise (vacuum/bracing confusion).
The myth
You have to actively 'pull the abs inward' on every exercise (vacuum/bracing confusion).
What the evidence says
Permanently pulling the belly in ("hollowing") weakens the stability of the lumbar spine under load. For optimal stability under heavy load, what is known as "bracing" is required – tensing the entire trunk musculature outward (as when expecting a blow to the belly).
Practice: Concrete implementation
The core message: bracing instead of hollowing – but not the same on every exercise. The belly is not permanently "pulled inward," but stabilized situationally. What matters is the load, the goal, and the exercise.
Example A — Weekly plan: When to use which strategy?
| Training day | Exercise (example) | Trunk strategy | Why |
|---|---|---|---|
| Day 1 – heavy | Squat, deadlift | Bracing (outward, 360°) | High load, spine needs maximum stability |
| Day 1 – heavy | Military press | Bracing, moderate | Upright position, keep ribs down |
| Day 2 – moderate | Rows, lat pulldown | Light bracing | Less axial load, but trunk stays active |
| Day 3 – core | Dead bug, Pallof press | Measured tension, no extreme pulling in | Control and anti-rotation instead of maximal force |
| Day 4 – light/technique | Kettlebell swings, carries | Bracing on every rep, rhythmic breathing | Stability under dynamic load |
Remember: hollowing (pulling the belly in) is not a training standard, but a targeted exercise for specific purposes (e.g., motor control) – not the default posture on every repetition.
Example B — Execution & coaching cues
Building bracing correctly:
- Stand upright, one hand on the belly, one on the side of the trunk wall.
- Breathe in deeply, then exhale lightly against a "closed" throat, as if you were expecting a blow to the belly.
- You feel tension toward the front, sides, and back – the belly stays round, not pulled in.
- Hold the tension, keep breathing normally (small breaths into the ribcage).
Coaching cues:
- "Push the belly outward, don't pull it in."
- "Stack the ribs over the pelvis."
- "As if you were about to take a light jab to the belly."
- "Breathe into the belly, not out of the belly."
Common mistakes:
- Permanently pulling the navel toward the spine → reduces stability under load.
- Holding the breath and pressing without control → blood pressure rises, technique suffers.
- Tensing only the "front," forgetting the sides and back.
Example C — Microcycle (4 weeks)
| Week | Focus | Implementation |
|---|---|---|
| 1 | Awareness | Practice bracing while standing for 2×5 breaths daily, then in the squat without weight |
| 2 | Light integration | Bracing on all compound lifts at 50–60% load, video check |
| 3 | Heavy integration | Bracing at 70–85% load, focus on constant tension across all repetitions |
| 4 | Automation | Bracing without conscious thought, check via video or partner feedback |
Ideal: You automatically build bracing before every heavy repetition, keep breathing in a controlled way, and feel tension around the entire trunk.
Good enough: You use bracing on the squat, deadlift, and press and avoid permanently pulling the belly in.
First step: Try the "blow-to-the-belly" test today on one exercise and compare the feeling with your previous technique.
Continue at the source
Read the original sourceFAQ
Should I pull my belly in on every exercise?
No. Permanently pulling in (hollowing) reduces the stability of the lumbar spine under load. On heavy exercises, bracing – tensing the trunk outward – is the better strategy. Hollowing can be useful as a targeted exercise, but not as the default posture on every repetition.
What is the difference between vacuum and bracing?
With the vacuum (hollowing), you actively pull the navel toward the spine. With bracing, you tense the entire trunk musculature outward, as if you were expecting a blow to the belly. Bracing creates more stability under heavy load.
How do I practice bracing correctly?
Stand upright, place one hand on the belly and one on the side. Breathe in deeply and then exhale lightly against a closed throat, as if you were expecting a jab. You should feel tension toward the front, sides, and back – the belly stays round, not pulled in. Hold the tension and keep breathing in small sips.