Core · Abs
Machine crunch
How to do the ab crunch machine: setup, flexing your spine without pulling with your arms, common mistakes and how to progress the load.
| Focus | Abs · obliques |
| Movement | Crunch |
| Equipment | Machine |
| Suggested sets | 3 × 20 |
| Estimated time | ≈ 5 min |
| Joints loaded |
Technique video
The machine crunch lets you train your abs with progressive load, just like any other muscle. Seated, with your chest or shoulders against pads, you curl your trunk against the weight stack. Unlike the floor crunch, you do not lift your head, so it does not strain your neck.
Muscles worked
The rectus abdominis, which flexes the spine by bringing the ribs toward the pelvis. The obliques assist.
How to do it
- Adjust the seat so the pads rest on your upper chest or shoulders, depending on the model.
- Hook your feet under the rollers if the machine has them.
- Hold the handles without pulling with your arms: they are only for support.
- Breathing out, curl your trunk down, as if bringing your ribs toward your hips.
- Hold for a second and return slowly to the start.
Common mistakes
- Pulling with your arms or pushing with your legs.
- Bending at the hips instead of the spine: the movement is a "curl".
- Too much weight with a short range.
- Snapping back to the start.
Progression
Like any muscle, your abs respond to progressive overload. Start with 15–20 reps and, once they feel easy, add a plate. The standing cable crunch is an alternative if you do not have a dedicated machine.
Precautions
It does not load any joint significantly. You do it seated without weight on your feet, so it suits an ankle injury or neck discomfort.
Log your sets for this exercise and see your progress month by month.
Start for freeIf you have an injury, pain or a medical condition, check with a professional before doing this exercise.