Hollow Rock

Muscles worked

Setup

1. Lie flat on your back on a mat with your legs straight and arms extended fully overhead.
2. Press your lower back firmly into the floor, ensuring there is no space between your spine and the mat.
3. Lift your legs 6-12 inches off the ground and raise your shoulder blades, keeping your chin tucked and arms glued to your ears.

How to do it

1. Maintain the rigid 'hollow' position and initiate a small rocking motion by shifting your weight slightly toward your legs and then back toward your shoulders.
2. Rock forward until your heels nearly touch the floor, then rock back until your shoulder blades nearly touch, keeping the angle of your body constant.
3. Maintain a steady tempo and use short, sharp exhales to keep your core braced throughout the movement.
4. Ensure the movement comes from your center of gravity, not by swinging your arms or legs independently.

Form checklist

• Lower back must remain in constant contact with the floor during the transition.
• Keep your legs squeezed together and toes pointed to engage the quadriceps.
• Arms must stay locked out behind your head, not reaching forward.
• The body should move as a single, solid piece like the base of a rocking chair.

Pro tips

• Focus on 'shortening' the distance between your ribcage and your pelvis to maximize the contraction of the rectus abdominis.
• Squeeze your glutes and quads as hard as possible; full-body tension makes the rocking motion more stable and effective.

Make it harder

• Hold a light weight plate or medicine ball overhead to increase the lever length and resistance.
• Slow the rocking tempo down significantly to increase the time under tension for the deep core muscles.

Frequently asked

What muscles does the hollow rock work?

The hollow rock primarily targets the abs and obliques, and also works the hip flexors as secondary muscles.

What equipment do you need for the hollow rock?

The hollow rock requires no equipment — just your body weight.

Is the hollow rock good for beginners?

The hollow rock is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

• 3/4 Sit-UpBeginner · abs and obliques
• 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
• 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
• 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals