Kettlebell Lying Triceps Extension Skull Crusher
- Target muscle
- —
- Equipment
- Kettlebell
- Body part
- Upper Arms
- Type
- Strength
The kettlebell lying triceps extension, also known as the skull crusher, targets the triceps of the upper arms by lowering a kettlebell toward your forehead from a locked-out position and pressing it back up. Performed with a kettlebell on a bench or the floor, it isolates the triceps through a long range of motion and is well suited for building upper-arm size and pressing strength.
How to do the Kettlebell Lying Triceps Extension Skull Crusher
- 1Lie on a flat bench or the floor, holding a kettlebell by the horns or the handle with both hands, arms extended directly above your chest.
- 2Plant your feet firmly on the floor and brace your core to keep your lower back stable throughout the movement.
- 3With your upper arms fixed and vertical, slowly bend your elbows to lower the kettlebell toward your forehead, keeping your elbows pointing straight ahead.
- 4Stop when the kettlebell is just above or level with your forehead — do not let it make contact with your head.
- 5Pause briefly at the bottom, maintaining tension in the triceps.
- 6Press the kettlebell back up by straightening your elbows until your arms are fully extended, returning to the starting position.
- 7Keep your upper arms stationary throughout every rep — only your forearms should move.
- 8Complete your reps, then carefully lower the kettlebell to your chest before sitting up.
Form tips
- Keep your upper arms perfectly vertical and still — if they drift forward or backward, you shift stress away from the triceps and onto the shoulders.
- Use a controlled tempo on the way down (2–3 seconds) to maximize triceps tension and reduce the risk of losing control of the kettlebell.
- Grip the kettlebell firmly at all times; because the weight distribution differs from a dumbbell, the bell can shift unpredictably if your grip loosens.
- Start with a lighter kettlebell than you think you need — the movement pattern is awkward at first and balance takes practice.
- Breathe in as you lower the kettlebell and breathe out as you press back up.
Common mistakes
- Letting the elbows flare outward as you lower the weight, which reduces triceps isolation and places unnecessary stress on the elbows and wrists.
- Moving the upper arms back and forth instead of keeping them fixed, which turns the exercise into a partial press and removes tension from the triceps.
- Lowering the kettlebell too fast with no control, which risks hitting your forehead and reduces time under tension.
- Locking out with excessive force at the top, which hyperextends the elbow joint and can cause joint irritation over time.
- Gripping only the handle rather than both horns, which makes the kettlebell harder to balance and increases the chance of it rotating out of control.
Frequently asked questions
What muscles does the kettlebell lying triceps extension skull crusher work?
It primarily targets the triceps of the upper arms. Because it is an isolation movement with a fixed elbow position, the triceps do virtually all of the work with minimal involvement from other muscle groups.
Can I do the skull crusher on the floor instead of a bench?
Yes. The floor limits how far your elbows can drop, which slightly shortens the range of motion but also makes the exercise more stable and beginner-friendly. A bench allows a fuller range of motion.
How do I hold the kettlebell for skull crushers?
The most stable grip is to hold the kettlebell by both horns (the sides of the handle) with both hands, keeping the bell facing upward. This distributes the weight evenly and gives you better control than gripping the handle alone.
How many sets and reps should I do for the kettlebell skull crusher?
For hypertrophy, 3–4 sets of 8–15 reps works well. Because the movement requires balance and control, higher reps with moderate weight are generally more productive — and safer — than going very heavy.
What is a good alternative to the kettlebell skull crusher?
The closest alternative is the dumbbell lying triceps extension, which follows the same movement pattern with more predictable weight distribution. A barbell EZ-bar skull crusher also targets the triceps through the same range of motion and allows heavier loading.
