Core · Dumbbell
Beginner Dumbbell Single Arm Starfish Crunch
How to do the beginner dumbbell single arm starfish crunch, the muscles it works, and the mistakes to avoid. Pulled straight from the Kovo app's exercise library.
- Equipment
- Dumbbell
- Difficulty
- Beginner
- Logged as
- Weighted reps
- Movement
- Rotation
- Mechanic
- Isolation
How to do it
Lie on your back in a spread starfish position, holding a single dumbbell in one hand extended overhead on the floor. Crunch up and bring the dumbbell across toward the opposite raised leg, then lower back to the start. Finish your reps on one side, then switch the dumbbell to the other hand.
- 1Feel your abs and obliques crunch and rotate the weight across
- 2Reach the dumbbell toward the opposite shin
- 3Lower slowly to keep the core under tension
Common mistakes
- Don't swing the weight up with arm momentum
- Avoid pulling on your neck or rounding hard at the top
- Don't let your lower back arch off the floor
Muscles worked
The beginner dumbbell single arm starfish crunch mainly works the obliques and upper abs, with the lower abs and hip flexors assisting.
- ObliquesPrimary
- Upper AbsPrimary
- Lower AbsSupport
- Hip FlexorsSupport
- ForearmsMinor
- LatsMinor
- QuadsMinor
- Front DeltsMinor
Kovo programs the beginner dumbbell single arm starfish crunch for you and tracks it every session.
We build your whole program, drop the right lifts into each workout, and adjust your weights as you get stronger. Free on iOS and Android.
More abs & core exercises
- How to do the ab wheel rollout
- How to do the ankle tap plank
- How to do the ankle taps
- How to do the resistance band dead bugs
- How to do the resistance band pallof press
- How to do the rollout
Last reviewed June 2026.