Floor Crunch: how to do it right
In short: The floor crunch isolates the rectus abdominis (mostly its upper part) with a tension peak in the shortened position, when your torso is curled.
How to do it, step by step
- 1Lie down, knees bent, feet on the floor, hands at your temples or crossed on your chest without pulling on your neck.
- 2Lift your shoulder blades off the floor by curling the spine, as if you wanted to bring the sternum toward the pubis.
- 3Rise until you feel your abs fully contracted, without trying to sit up.
- 4Squeeze hard for 1 second at the top, in the shortened position, exhaling fully.
- 5Control the return slowly without fully resting your shoulder blades between reps.
The mistake to avoid
Don't yank your neck with your hands. Curl with your abs.
Other common mistakes
- Pulling on the neck with your hands: keep the cervical spine neutral and let the abs do the work.
- Going down toward the floor without owning the top: slow down and squeeze 1 second in the shortened position, that's where the tension is.
- Sitting all the way up using the hips: it stays a curl of the back, pelvis fixed on the floor.
- Going too fast by swinging: control the return and remove momentum to keep tension on the muscle.
Muscles worked
- Main:
- Abs
The rectus abdominis is the prime mover, especially the supra-umbilical portion that brings the sternum toward the pubis. The obliques stabilize the trunk and keep the torso from drifting sideways. The transversus abdominis acts as bracing to keep the midsection tight. No notable secondary muscle works under load.
What to replace it with
Same muscle, same part of the movement: these exercises do the same job.
Frequently asked questions
How do I do this exercise?
On your back, knees bent, hands at your temples without pulling on your neck. Lift your shoulder blades by curling the spine, as if bringing your sternum closer to your pubis. Squeeze for one second at the top while exhaling fully, then come back without fully resting.
How high do I come up?
Just enough to lift the shoulder blades and feel the abs fully tight. Continuing to a seated position works the hip flexors, not the abs. Short range, intense contraction.
I don't feel anything, is that normal?
You should feel the upper abs burn. If you feel your neck, you're pulling with your hands. If you feel the front of your hips, you're coming up too high. Exhale fully at the top, it changes everything for the contraction.
How fast do I do the movement?
Slowly, with a one-second squeeze at the top. On this movement, forget the rep count and think about the quality of the peak: imagine you're crushing a sponge between your sternum and your pubis.