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  3. Exercises
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  5. Core & Abs
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  7. Crunch On A Bench

Exercise guide

Crunch On A Bench

  • Beginner
  • Isolation
  • Rep-based
  • Waist

The bench crunch isolates the rectus abdominis by providing a stable, elevated surface that helps minimize hip flexor involvement and maximize abdominal tension.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Crunch On A Bench demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Abs
  • Obliques

Secondary

  • Erector spinae

Equipment

  • Body weight

Setup

  1. Lie face-up on a flat bench with your feet flat on the bench and knees bent at a 90-degree angle.
  2. Position your head near the end of the bench and place your hands lightly behind your ears or crossed over your chest.
  3. Press your lower back firmly into the surface of the bench to eliminate any arch.

How to do it

  1. Exhale as you contract your abdominals to lift your head and shoulder blades 3-4 inches off the bench.
  2. Curl your torso forward, focusing on bringing your ribcage toward your pelvis while keeping the lower back grounded.
  3. Inhale as you slowly lower your shoulders back to the starting position using a controlled 2-second tempo.

Form checklist

  • Keep your lower back in constant contact with the bench throughout the entire rep.
  • Avoid pulling on your neck with your hands; your core should do all the lifting.
  • Maintain a small gap (about the size of an orange) between your chin and your chest.
  • Keep your feet planted firmly on the bench to stabilize your hips and pelvis.

Pro tips

  • Visualize your abdominal muscles shortening and 'peeling' your upper spine off the bench one vertebra at a time.
  • Pause and squeeze your abs at the top of the movement for a full second to maximize muscle fiber recruitment.

Make it harder

  • Hold a weight plate or dumbbell securely against your chest to add resistance.
  • Extend your arms straight overhead to increase the lever arm, making the bodyweight lift significantly more difficult.

Frequently asked

What muscles does the crunch on a bench work?
The crunch on a bench primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
What equipment do you need for the crunch on a bench?
The crunch on a bench requires no equipment — just your body weight.
Is the crunch on a bench good for beginners?
Yes. The crunch on a bench 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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