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  3. Exercises
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  5. Core & Abs
  6. /
  7. Lying Ab Press

Exercise guide

Lying Ab Press

  • Beginner
  • Isolation
  • Rep-based
  • Waist

The Lying Ab Press is a foundational isometric core exercise that builds deep abdominal stability and oblique strength by creating internal resistance. It is highly effective for teaching pelvic control and bracing while keeping the lower back protected.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Lying Ab Press demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae
  • Hip flexors

Equipment

  • Body weight

Setup

  1. Lie flat on your back on a mat with your legs in a tabletop position (hips and knees bent at 90 degrees).
  2. Lift your feet so your shins are parallel to the floor.
  3. Place your palms firmly against your thighs, just above your knees, with your arms slightly bent.

How to do it

  1. Take a deep breath in to expand your ribcage, then exhale forcefully as you press your hands into your knees.
  2. Simultaneously use your core to pull your knees toward your chest, resisting the push from your hands to create maximum tension.
  3. Hold this peak isometric contraction for 3-5 seconds while maintaining a flat lower back.
  4. Inhale as you slowly release the pressure, keeping your legs in the tabletop position for the next rep.

Form checklist

  • Keep your lower back glued to the floor throughout the entire movement.
  • Maintain a 90-degree angle at the knees; do not let your feet drop toward your glutes.
  • Keep your neck neutral and shoulders relaxed, avoiding shrugging toward your ears.
  • Ensure the resistance comes from your core, not just your arm strength.

Pro tips

  • Imagine you are trying to crush a walnut between your hands and knees to maximize muscle recruitment.
  • Focus on 'knitting' your ribs down toward your hip bones to engage the transverse abdominis and obliques.

Make it harder

  • Perform a unilateral version by pressing one hand into the opposite knee while extending the other leg straight out just above the floor.
  • Increase the duration of the isometric hold to 10-15 seconds per repetition.

Frequently asked

What muscles does the lying ab press work?
The lying ab press primarily targets the abs and obliques, and also works the erector spinae and hip flexors as secondary muscles.
What equipment do you need for the lying ab press?
The lying ab press requires no equipment — just your body weight.
Is the lying ab press good for beginners?
Yes. The lying ab press is a beginner-friendly movement and a strong foundation to build on.

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

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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