How long should you hold and rock in the arch-body rock when you are new to the exercise?

Start with 3 sets of 5 to 6 small rocks, holding the arch shape for roughly 15 to 20 seconds total per set. Keep the rocking motion small until it feels smooth and continuous, then let the rocks get slightly bigger before adding more of them per set.

How do you make the arch-body rock easier or harder?

To make it easier, keep the arms down at your sides instead of overhead, which shortens the lever your back has to lift. To make it harder, hold the overhead position and add a longer static hold before you start rocking, or extend the total rocking time per set.

What is the arch-body rock good for, and when should you skip it?

It builds spinal extension strength and posterior-chain tension that balance out hollow-heavy core training, useful for anyone doing a lot of anti-extension work elsewhere. Skip it, or keep the range very small, with any current low-back pain, since it's a sustained extension hold and can aggravate an already irritated spine.

Intermediate

Arch-Body Rock

The arch-body rock is the extension counterpart to the hollow rock and a must-have for balanced core training. Face down in a tight arch with the chest, arms, and legs lifted, you rock along the front of your body while the erectors, glutes, and hamstrings hold the shape. It builds the spinal extension strength and posterior tension that keep hollow-heavy programs from becoming lopsided.

Equipment: Body Weight
Body part: Back, Glutes
Type: Functional, Strength
Browse by muscle: Erector Spinae, Gluteus Maximus
Browse by movement: Hinge

How to do it

1
Lie face down with arms reaching overhead and legs straight.
2
Lift the chest, arms, and legs off the floor into a tight arch.
3
Squeeze the glutes and pinch the shoulder blades to hold the shape.
4
Rock forward and backward along your torso and thighs in small waves.
5
Keep the arch rigid so the whole body rocks as one piece.
6
Lower under control once you finish the set.

Tips

Drive the lift from the glutes and mid-back, not by cranking the neck.
Keep a small rock at first; the tighter the arch, the smoother it rolls.
Keep the arms and legs long and lifted the whole time rather than dropping them.

Variations

Common mistakes

The neck cranks back to lift the head higher, straining the cervical spine instead of letting the glutes and back drive the arch.
Letting the arms or legs drop toward the floor between rocks turns a continuous hold into a series of separate lifts.
The rock gets driven from bending at the hips instead of the whole rigid body moving as one piece, which is the entire point of the drill.
Making the rock too big before the small version feels smooth trades control for a bigger, sloppier swing.
The glutes relax between rocks once the initial squeeze is set, letting the low back take over an extension it wasn't meant to hold alone.

Frequently asked

How long should you hold and rock in the arch-body rock when you are new to the exercise?: Start with 3 sets of 5 to 6 small rocks, holding the arch shape for roughly 15 to 20 seconds total per set. Keep the rocking motion small until it feels smooth and continuous, then let the rocks get slightly bigger before adding more of them per set.
How do you make the arch-body rock easier or harder?: To make it easier, keep the arms down at your sides instead of overhead, which shortens the lever your back has to lift. To make it harder, hold the overhead position and add a longer static hold before you start rocking, or extend the total rocking time per set.
What is the arch-body rock good for, and when should you skip it?: It builds spinal extension strength and posterior-chain tension that balance out hollow-heavy core training, useful for anyone doing a lot of anti-extension work elsewhere. Skip it, or keep the range very small, with any current low-back pain, since it's a sustained extension hold and can aggravate an already irritated spine.

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