How to do the Dumbbell Skull Crusher
- Lie on your back on a bench, holding a dumbbell in each hand above your shoulders.
- Let your upper arms hang almost straight up, elbows pointing toward the ceiling.
- Bend your elbows to lower the dumbbells slowly beside your head.
- Straighten your arms back up to the starting position, feeling the triceps work.
Full technique — 7 steps
- Lie flat on a bench with feet planted and a dumbbell held above your shoulders in each hand.
- Use a neutral grip and set your upper arms nearly vertical with elbows pointing upward.
- Tighten your stomach and keep your shoulders quiet as the movement comes only from the elbows.
- Bend your elbows to lower the dumbbells beside your forehead or just behind your head.
- Stop when your forearms reach full comfortable flexion and your upper arms have stayed mostly in place.
- Extend your elbows to drive the dumbbells back to the start without letting them drift forward.
- Finish with the dumbbells directly over your shoulders and the triceps fully shortened.
Common mistakes
- Upper arms drifting backward excessively
- Turning it into a press
- Elbows flaring wide apart
- Cutting the bottom range short
Form cues
- Move only at elbows
- Keep upper arms still
- Lower beside the head
- Use a neutral grip
Substitutes by equipment
Same muscles, same movement — pick the version you have the gear for.
Cable machine
- Triceps Pushdown (Rope) Easier
- Triceps Pushdown (Bar) Easier
Barbell
- Barbell Skull Crusher Same level
Resistance bands
Machine
- Ski Erg Triceps Extension Easier
- Ski Erg Triceps Pushdown Easier
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 Bilateral Dumbbell Triceps Kickback
- Easier Dumbbell Overhead Triceps Extension
- This exercise Dumbbell Skull Crusher
- Harder Bodyweight Triceps Extension
Too hard for now? Start with the Dumbbell Overhead Triceps Extension.
Quick answers
What muscles does the Dumbbell Skull Crusher work?
Primary: Triceps 10/10.
When should I do the Dumbbell Skull Crusher in a workout?
Finisher. Goes last, once the heavy work is done. ≈ 6 min with rest.
How many sets and reps of the Dumbbell Skull Crusher?
Strength: 4–5 sets of 6–8 reps, rest 2 min, 2 reps in reserve. Muscle growth: 3–4 sets of 8–12 reps, rest 1 min 15 s, 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 Dumbbell Skull Crusher?
Cable machine: Triceps Pushdown (Rope), Triceps Pushdown (Bar). Barbell: Barbell Skull Crusher. Resistance bands: Resistance Band Overhead Triceps Extension, Single Arm Resistance Band Triceps Pushdown. Machine: Ski Erg Triceps Extension, Ski Erg Triceps Pushdown.
What is an easier version of the Dumbbell Skull Crusher?
Dumbbell Overhead Triceps Extension (Beginner), Bilateral Dumbbell Triceps Kickback (Beginner).
What is a harder version of the Dumbbell Skull Crusher?
Bodyweight Triceps Extension (70% of bodyweight).
