How to do the Single Arm Dumbbell Cross Body Crunch
- Lie flat, arms and legs spread, a dumbbell in one hand.
- Lift your torso and reach the dumbbell toward the opposite foot.
- Raise that leg straight up to meet it.
- Lower slowly, then switch sides after all reps.
Full technique — 8 steps
- Lie on your back with legs straight and arms spread wide on the floor, a dumbbell in one hand.
- Keep your free hand flat on the floor for support.
- Press your lower back into the floor and keep your ribs pulled down.
- Exhale and lift your upper back off the floor, reaching the dumbbell across your body toward the opposite foot.
- At the same time, raise the opposite leg straight up until it is close to vertical.
- Keep the other leg long and low on the floor.
- Lower your arm, torso, and leg back to the floor under control.
- Complete all reps on one side, then switch arms.
Common mistakes
- Swinging the leg with momentum
- Swinging arms for momentum
- Bending knees to shorten range
- Dropping into the next rep
Form cues
- Exhale into the crunch
- Reach toward your toes
- Lift with abs first
- Keep knees straight
Substitutes by equipment
Same muscles, same movement — pick the version you have the gear for.
Medicine ball
Barbell
Where to start and where to go next
Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.
- Easier Tall Kneeling Dumbbell Woodchop
- Easier Half Kneeling Dumbbell Low-to-High Woodchop
- This exercise Single Arm Dumbbell Cross Body Crunch
- Harder Side Plank Reach Through
Too hard for now? Start with the Half Kneeling Dumbbell Low-to-High Woodchop.
Quick answers
What muscles does the Single Arm Dumbbell Cross Body Crunch work?
Primary: Obliques 8/10, Abs 8/10.
When should I do the Single Arm Dumbbell Cross Body Crunch in a workout?
Finisher. Goes last, once the heavy work is done. ≈ 7 min with rest.
How many sets and reps of the Single Arm Dumbbell Cross Body Crunch?
Strength: 3–4 sets of 8–10 reps, rest 1 min 15 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 15–20 reps, rest 45 s, 3–4 reps in reserve.
What can I do instead of the Single Arm Dumbbell Cross Body Crunch?
Medicine ball: Half Kneeling Medicine Ball Woodchop. Barbell: Tall Kneeling Landmine Rotation.
What is an easier version of the Single Arm Dumbbell Cross Body Crunch?
Half Kneeling Dumbbell Low-to-High Woodchop (Beginner), Tall Kneeling Dumbbell Woodchop (Beginner).
What is a harder version of the Single Arm Dumbbell Cross Body Crunch?
Side Plank Reach Through (45% of bodyweight).
