Primary
Triceps
Secondary
Shoulders
Equipment
Ez Bar
Difficulty
Intermediate
Type
Push
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Skull crushers—also called lying tricep extensions—are a free weight mass builder for the triceps long head. The lying position allows heavier loading than standing overhead variations while still placing the long head under stretch. The exercise gets its name from the bar path, which travels toward your forehead or just behind your head.
When to use it
Use as a primary tricep mass builder in arm workouts.
Who it's for
Intermediate lifters wanting tricep mass.
Keep your elbows pointed at the ceiling throughout—do not let them flare outward. Lower the bar toward your forehead or slightly behind your head for a better stretch. Control the eccentric carefully; this is not an exercise to rush.
Also targets: Shoulders
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Lie on bench holding EZ bar with narrow grip.
Extend arms straight up over chest.
Lower bar toward forehead by bending elbows.
Keep upper arms stationary throughout.
Extend elbows to push bar back up.
Squeeze triceps at the top.
Also known as lying tricep extension.
Keep elbows pointed at ceiling.
Can lower behind head for more stretch.
Program skull crushers as your primary tricep isolation movement on arm days, or after compound pressing on push days. The free weight loading makes them ideal for progressive overload in the 8-12 rep range. Follow with pushdowns for complete tricep coverage.
Letting elbows flare out.
Letting your elbows drift wide during the Skull Crusher shifts load onto your shoulder joint instead of your Triceps (long head emphasis). Keep them tucked at about 45 degrees to protect your rotator cuff and keep tension where it belongs.
Lowering to nose instead of forehead/behind head.
Craning your neck during the Skull Crusher compresses your cervical spine and can cause nerve impingement. Keep your head in a neutral position — pick a spot to look at and hold it through the set.
Using too much weight.
Loading more weight than you can control on the Skull Crusher forces compensatory movement patterns that bypass your Triceps (long head emphasis). Drop the weight until you can perform every rep with clean form — your results will actually improve.
Intermediate lifters wanting tricep mass.
Lower reps with heavier weight builds raw strength. Your muscles and nervous system adapt to handle more load over time. This range is best for strength-focused goals.
This rep range keeps your muscles under tension long enough to trigger growth. Most people see the best muscle-building results in this zone. It balances strength and muscle size.
Higher reps with lighter weight builds muscular endurance and improves conditioning. This range is good for joint health and building work capacity.
General guideline: 3 sets of 10-12 reps. Rest 60-90 seconds.
MySetPlan places Skull Crusher inside a complete workout — with the right sets, reps, rest periods, and a progression you can follow week to week.
Sample workout
MySetPlan guides you set by set, times your rest, lets you swap if equipment is busy, and tells you what to do next.
Try Gym Mode FreeSkull crushers and the overhead cable extension both target the long head, but through different tension profiles. Skull crushers use free-weight resistance that peaks at the bottom and disappears at the top. The overhead cable version keeps tension constant through the full range. Rotate between them across training blocks to hit the long head from two angles.
MySetPlan picks the right exercises for your goals — like the Skull Crusher — and builds them into a monthly program. Every set, every rep, planned out.
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Skull crushers stretch the long head for more growth potential, while pushdowns are easier to perform and excellent for volume. Use both for complete tricep development.
Skull crushers allow heavier loading with a horizontal pressing angle, while overhead extensions maximize long head stretch. Both effectively build the triceps long head.
Skull Crusher
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Frequently Asked Questions About the Skull Crusher
The Skull Crusher primarily targets the Triceps (long head emphasis), making it an effective exercise for triceps development. Secondary muscles worked during the Skull Crusher include Anconeus, providing additional training stimulus. Stabilizer muscles engaged include Shoulders, Core.
The Skull Crusher is rated as intermediate difficulty, meaning it requires some training experience. Intermediate lifters wanting tricep mass. Focus on proper technique and consider starting with easier variations.
For the Skull Crusher, the recommended approach depends on your goals. 3 sets of 10-12 reps. Rest 60-90 seconds. For strength, use 6-8 reps. For muscle growth, perform 8-12 reps. For endurance, complete 12-15 reps.
The Skull Crusher typically requires a ez bar, which most home gyms don't have. For a home-friendly alternative targeting the same muscles, check the variations section above.
Good alternatives to the Skull Crusher include: Overhead Tricep Extension, Close-Grip Bench Press, Tricep Pushdown, Overhead Cable Extension. These exercises target similar muscle groups as the Skull Crusher and can be used as substitutes based on your equipment availability, gym setup, or training preferences.