# Medicine Ball Straight Arm Crunch

A floor crunch holding a medicine ball in straight arms above your chest, pushing it toward the ceiling as your upper back lifts. Adds load to the crunch to train the abs.

- Beginner · Isolation
- Equipment: Medicine ball
- HD video: https://media.seto.fit/exercises/crunch-with-medicine-ball/video/male.mp4
- HTML: https://seto.fit/exercises/medicine-ball-straight-arm-crunch/

## Muscles worked

- Abs: 10/10
- Obliques: 5/10

## How to do the Medicine Ball Straight Arm Crunch

1. Lie on your back, knees bent, holding a medicine ball above your chest.
2. Curl your head and shoulders up, pushing the ball toward the ceiling.
3. Keep your arms straight and your lower back on the floor.
4. Slowly lower back down until your upper back touches the floor again.

### Full technique — 7 steps

1. Lie on your back with knees bent and feet flat on the floor.
2. Hold a medicine ball with both hands, arms straight above your chest.
3. Press your lower back into the floor and keep your ribs pulled down.
4. Curl your head, shoulders, and upper back off the floor by shortening your abs.
5. Push the ball toward the ceiling as you rise, keeping your arms straight.
6. Lift until your shoulder blades clear the floor without turning it into a sit-up.
7. Lower your upper back down until your shoulder blades return to the floor.

## Common mistakes

- Bending the elbows to move the ball
- Letting the ball drift behind your head
- Turning reps into sit-ups
- Lower back arching off floor
- Swinging up with momentum

## Form cues

- Keep arms straight
- Reach toward the ceiling
- Keep low back down
- Lift shoulder blades only
- Exhale into the crunch

## How much to do

- **Strength**: 3–4 sets of 8–12 reps · rest 1 min 15 s · 2–3 reps in reserve · lower 2 s, pause 1 s, lift 1 s
- **Muscle growth** (good fit): 3–4 sets of 12–20 reps · rest 1 min · 2–3 reps in reserve · lower 2 s, pause 1 s, lift 2 s
- **Endurance** (best fit): 2–3 sets of 20–30 reps · rest 45 s · 3–4 reps in reserve · lower 2 s, lift 1 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**: [Seated Leg Raise](https://seto.fit/exercises/seated-leg-raise/), [Ab Wheel Straight Arm Crunch](https://seto.fit/exercises/ab-wheel-straight-arm-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/)
- **Suspension trainer**: [Suspension Trainer Hanging Knee Raise](https://seto.fit/exercises/suspension-trainer-hanging-knee-raise/), [Suspension Trainer Hanging Leg Raise](https://seto.fit/exercises/suspension-trainer-hanging-leg-raise/)

## 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: Medicine Ball Straight Arm Crunch — Beginner**
- Harder: [Medicine Ball Toe Touch Crunch](https://seto.fit/exercises/medicine-ball-toe-touch-crunch/) — Beginner
- Harder: [Ab Wheel Half Rollout](https://seto.fit/exercises/ab-wheel-half-rollout/) — 40% of bodyweight

## Quick answers

### What muscles does the Medicine Ball Straight Arm Crunch work?

Primary: Abs 10/10. Also works: Obliques 5/10.

### When should I do the Medicine Ball Straight Arm Crunch in a workout?

Finisher. Goes last, once the heavy work is done. ≈ 5 min with rest.

### How many sets and reps of the Medicine Ball Straight Arm Crunch?

Strength: 3–4 sets of 8–12 reps, rest 1 min 15 s, 2–3 reps in reserve. Muscle growth: 3–4 sets of 12–20 reps, rest 1 min, 2–3 reps in reserve. Endurance: 2–3 sets of 20–30 reps, rest 45 s, 3–4 reps in reserve.

### What can I do instead of the Medicine Ball Straight Arm Crunch?

No equipment: Seated Leg Raise, Ab Wheel Straight Arm Crunch. Dumbbells: Dumbbell Decline Sit-Up, Dumbbell Straight Arm Crunch. Resistance bands: Lying Resistance Band Crunch, Lying Resistance Band Knee Tuck. Suspension trainer: Suspension Trainer Hanging Knee Raise, Suspension Trainer Hanging Leg Raise.

### What is a harder version of the Medicine Ball Straight Arm Crunch?

Medicine Ball Toe Touch Crunch (Beginner), Ab Wheel Half Rollout (40% of bodyweight).

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

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