Dumbbell Straight Arm Crunch — how to, muscles worked, alternatives

How to do the Dumbbell Straight Arm Crunch

Lie on your back, knees bent, holding one dumbbell above your chest.
Curl your head and shoulders up, pushing the dumbbell toward the ceiling.
Keep your arms straight and your lower back on the floor.
Slowly lower back down until your upper back touches the floor again.

Full technique — 7 steps

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

Common mistakes

Bending the elbows to move the dumbbell
Letting the dumbbell 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

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 Dumbbell Straight Arm Crunch Beginner
Harder Dumbbell Toe Touch Crunch Beginner
Harder Dumbbell Decline Sit-Up 40% of bodyweight

Quick answers

What muscles does the Dumbbell Straight Arm Crunch work?

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

When should I do the Dumbbell 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 Dumbbell Straight Arm Crunch?

Strength: 3–4 sets of 8–10 reps, rest 1 min 30 s, 2 reps in reserve. Muscle growth: 3–4 sets of 10–15 reps, rest 1 min, 2–3 reps in reserve. Endurance: 2–3 sets of 20–25 reps, rest 45 s, 3–4 reps in reserve.

What can I do instead of the Dumbbell Straight Arm Crunch?

No equipment: Ab Wheel Straight Arm Crunch, Alternating Tuck-Up. 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.