Crunch with Legs on Stability Ball — how to, muscles worked, alternatives

How to do the Crunch with Legs on Stability Ball

Lie on your back, lower legs resting on the ball.
Hands behind your head, elbows out to the sides.
Curl your shoulder blades off the floor, legs still.
Lower your shoulders slowly back to the floor.

Full technique — 6 steps

Lie on your back with your hips and knees bent to about 90 degrees.
Rest the backs of your lower legs on top of a stability ball.
Place your hands lightly behind your head with elbows pointing out to the sides.
Exhale and curl your head, neck, and shoulder blades up off the floor.
Keep your legs and the ball still as your ribs move toward your pelvis.
Lower your shoulders back to the floor under control, then repeat.

Common mistakes

Pulling the head with hands
Swinging the torso with momentum
Letting the ball roll away
Dropping into the next rep

Form cues

Curl ribs toward pelvis
Hands stay by head
Keep chin neutral
Exhale on the curl
Keep the ball still

Substitutes by equipment

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

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 Crunch with Legs on Stability Ball 15% of bodyweight
Harder Reverse Crunch 25% of bodyweight
Harder Ab Wheel Pass Crunch 30% of bodyweight

Quick answers

What muscles does the Crunch with Legs on Stability Ball work?

Primary: Abs 9/10. Also works: Obliques 5/10.

When should I do the Crunch with Legs on Stability Ball in a workout?

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

How many sets and reps of the Crunch with Legs on Stability Ball?

Strength: 2–3 sets of 10–15 reps, rest 1 min, 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 Crunch with Legs on Stability Ball?

Dumbbells: Dumbbell Decline Sit-Up, Dumbbell Straight Arm Crunch. Resistance bands: Lying Resistance Band Crunch, Lying Resistance Band Knee Tuck. Medicine ball: Medicine Ball Toe Touch Crunch, Medicine Ball Straight Arm Crunch. Suspension trainer: Suspension Trainer Hanging Knee Raise, Suspension Trainer Hanging Leg Raise.