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Core ยท Trunk flexion

Machine Crunch

An isolation trunk flexion exercise for the abs, done with a machine.

Machine Isolation Reps and weight Also called: ab crunch machine, ab machine

Muscles worked

Primary

Abs

Do most of the work.

Secondary

None to speak of

This one is focused.

  • AbsFront of the trunkPrimary

How to do it

  1. Set the machine. Adjust the seat and pads so the joint that moves lines up with the machine pivot, then pick the weight.
  2. Curl the ribs towards the pelvis, round the spine.
  3. Exhale as you crunch, pause at the bottom.
  4. Do not pull with the arms or the neck.
  5. Control every rep. Breathe out through the hardest part and stop the set when your form changes.

Common mistakes

  • Pulling on the neck. Hands stay light; the abs do the work.
  • Swinging. Move slowly and pause at the end of each rep.

Machine busy? Try one of these

General guidance, not medical advice. If a movement hurts, stop and ask a qualified coach or physio.