# Seated Ab Machine

A machine-based trunk flexion exercise targeting the abdominals. Useful for lifters who want direct abdominal loading with stable positioning.

- Beginner · Isolation
- Equipment: Ab machine
- HD video: https://media.seto.fit/exercises/abdominal-crunches-machine/video/male.mp4
- HTML: https://seto.fit/exercises/seated-ab-machine/

## Muscles worked

- Abs: 10/10

## How to do the Seated Ab Machine

1. Adjust the seat so the back pad comfortably touches your upper back.
2. Hook your ankles under the foot rollers and hold the chest pads.
3. Sit upright, keeping your chest facing forward and hips still.
4. Flex your trunk to curl your ribcage toward your pelvis.
5. Slowly return to the starting position, controlling the movement.

### Full technique — 7 steps

1. Adjust the seat and pads so the back pad contacts your upper torso comfortably.
2. Hook your ankles under the foot rollers and hold the chest pads with both arms.
3. Sit tall against the pad with hips fixed and your chest facing forward.
4. Lightly tighten your stomach, then flex your trunk to curl your ribcage toward your pelvis.
5. Continue until you reach your strongest shortened abdominal position without yanking on the chest pads.
6. Squeeze the abs briefly at the end range of the crunch.
7. Reverse the motion under control until your torso returns to the machine's start position.

## Common mistakes

- Pulling the chest pads with your arms
- Using momentum to start reps
- Stopping short of trunk flexion
- Letting hips shift on seat

## Form cues

- Curl ribcage toward pelvis
- Keep hips pinned down
- Move through your trunk
- Exhale into the crunch

## How much to do

- **Muscle growth** (best fit): 3–4 sets of 8–12 reps · rest 1 min 15 s · 2–3 reps in reserve · lower 2 s, pause 1 s, lift 2 s
- **Endurance** (good fit): 2–3 sets of 15–20 reps · rest 45 s · 3–4 reps in reserve · lower 2 s, lift 2 s

Reps in reserve: how many more you could still do when you end the set.

## Substitutes by equipment

Same muscles, same movement — pick the version you have the gear for.

- **No equipment**: [Reverse Crunch](https://seto.fit/exercises/reverse-crunch/), [Ab Wheel Pass Crunch](https://seto.fit/exercises/ab-wheel-crunch/)
- **Medicine ball**: [Medicine Ball Straight Arm Crunch](https://seto.fit/exercises/medicine-ball-straight-arm-crunch/), [Medicine Ball Toe Touch Crunch](https://seto.fit/exercises/medicine-ball-toe-touch-crunch/)
- **Dumbbells**: [Dumbbell Decline Sit-Up](https://seto.fit/exercises/dumbbell-decline-sit-up/), [Dumbbell Straight Arm Crunch](https://seto.fit/exercises/dumbbell-straight-arm-crunch/)
- **Resistance bands**: [Lying Resistance Band Crunch](https://seto.fit/exercises/lying-resistance-band-crunch/), [Lying Resistance Band Knee Tuck](https://seto.fit/exercises/lying-resistance-band-knee-tuck/)

## Where to start and where to go next

Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.

- **This exercise: Seated Ab Machine — Beginner**
- Harder: [Cable Crunch](https://seto.fit/exercises/cable-crunch/) — Beginner
- Harder: [Ab Wheel Rollout](https://seto.fit/exercises/ab-wheel-rollout/) — 80% of bodyweight

## Quick answers

### What muscles does the Seated Ab Machine work?

Primary: Abs 10/10.

### When should I do the Seated Ab Machine in a workout?

Finisher. Goes last, once the heavy work is done. ≈ 6 min with rest.

### How many sets and reps of the Seated Ab Machine?

Muscle growth: 3–4 sets of 8–12 reps, rest 1 min 15 s, 2–3 reps in reserve. Endurance: 2–3 sets of 15–20 reps, rest 45 s, 3–4 reps in reserve.

### What can I do instead of the Seated Ab Machine?

No equipment: Reverse Crunch, Ab Wheel Pass Crunch. Medicine ball: Medicine Ball Straight Arm Crunch, Medicine Ball Toe Touch Crunch. Dumbbells: Dumbbell Decline Sit-Up, Dumbbell Straight Arm Crunch. Resistance bands: Lying Resistance Band Crunch, Lying Resistance Band Knee Tuck.

### What is a harder version of the Seated Ab Machine?

Cable Crunch (Beginner), Ab Wheel Rollout (80% of bodyweight).

How we rate exercises: https://seto.fit/guides/methodology/

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