Arms · Isolation
Skullcrusher
The skullcrusher is a triceps isolation exercise where you lie on a bench and lower a barbell or EZ bar towards your forehead by bending the elbows, then extend back to lockout. Keeping the upper arms angled back loads the long head of the triceps in a stretched position, which pushdowns do not.
Also known as: Lying triceps extension, French press, EZ bar skullcrusher, Nose breaker
- Muscle group
- Arms
- Movement pattern
- Isolation
- Type
- Isolation
- Equipment
- EZ bar, Barbell, Flat bench
- Difficulty
- Intermediate
What muscles does the skullcrusher work?
Primary movers
- Triceps brachii (long head)
Assisting muscles
- Triceps brachii (lateral head)
- Triceps brachii (medial head)
- Anconeus
- Forearm extensors
The long head of the triceps is the reason to do this exercise. Unlike the other two heads, it crosses the shoulder as well as the elbow, so its length depends on where the upper arm is. Lying with the arms angled slightly back over the head puts it on stretch before each rep begins.
That matters because the long head is the largest of the three heads and the one most responsible for the mass on the back of the upper arm. A pushdown, with the elbows locked at the sides, trains it in a shortened position and therefore trains it least.
Training a muscle in a lengthened position is one of the better-supported drivers of hypertrophy, which is why lying and overhead extensions consistently outperform pushdowns for long head development in the research that has looked at it.
The lateral and medial heads still work in full, since both cross the elbow and elbow extension is what the exercise asks for. The whole triceps is trained here; the difference is one of emphasis rather than exclusion.
The elbow takes real stress in the stretched position, which is why the exercise earned a name suggesting things can go wrong. Using an EZ bar, keeping the load moderate and controlling the descent addresses nearly all of that.
How to do the skullcrusher
Setup
- 1
Load an EZ bar and sit on the end of a flat bench with it resting on your thighs.
- 2
Lie back while bringing the bar up to arm's length above your chest.
- 3
Take a grip roughly shoulder-width, using the angled portion of the bar.
- 4
Angle your upper arms back slightly so the bar sits above your forehead rather than your chest.
- 5
Plant your feet flat and brace your abs so your back stays in a natural position.
Execution
- 1
Bend at the elbows to lower the bar towards your forehead or just behind your head.
- 2
Keep your upper arms fixed at their angle, only the forearms should move.
- 3
Lower until you feel a stretch in the triceps, without letting the elbows flare outward.
- 4
Extend the elbows to press the bar back to the start position.
- 5
Stop just short of a hard lockout to keep tension on the triceps.
- 6
Control the descent over two to three seconds on every repetition.
Common skullcrusher mistakes
Flaring the elbows outward
Letting the elbows spread wide as the bar comes down. It converts the movement into a partial press, brings the chest and shoulders in, and reduces the load on the triceps.
The fix: Keep the elbows pointing forward and roughly shoulder-width apart. If they spread on the last few reps, the set has ended.
Moving the upper arms
Letting the elbows swing back and forth so the shoulders help lift the bar. The triceps is no longer isolated and the range that actually loads it is skipped.
The fix: Fix your upper arm angle before the first rep and hold it. Only the forearm should move. Think of your elbow as a hinge bolted in place.
Going too heavy for the elbow
The stretched bottom position places real stress across the elbow joint, and heavy loading there is where this exercise causes problems.
The fix: Keep the load moderate and the reps in the 8–15 range. This is not a lift to test maximum strength on.
Using a straight bar with sore wrists
A straight bar forces a fixed hand position that many people find aggravates the wrist and elbow, particularly at the bottom of the movement.
The fix: Use an EZ bar. The angled grip removes most of the strain for most lifters with no meaningful loss of triceps involvement.
How many sets and reps?
| Goal | Sets | Reps | Load | Rest |
|---|---|---|---|---|
| Hypertrophy | 3–4 | 8–12 | Moderate, 1–2 RIR | 90 s |
| Stretch-emphasis work | 3 | 10–15 | Light to moderate, slow eccentric | 60–90 s |
| Strength-biased | 3–4 | 6–8 | Heavy, strict | 2 min |
Skullcrushers pair naturally with pushdowns rather than competing with them: one trains the long head in a stretched position, the other trains the lateral and medial heads with constant tension and no elbow stress. Two to four sets once or twice a week is sufficient. Lower the bar behind your head rather than directly to your forehead if you want more long head stretch. It keeps constant tension and, for most people, feels better on the elbows.
Running the skullcrusher in your next block? Hercules logs every set, shows last session's numbers before you lift, and suggests when to add weight.
Get it on Google PlaySkullcrusher variations and alternatives
EZ Bar Skullcrusher
EasierThe angled grip reduces wrist and elbow strain substantially. This is the default version for most lifters rather than a regression.
Dumbbell Skullcrusher
AlternativeIndependent arms let each side follow its own path and permit a neutral grip, which many people find far easier on the elbows.
Incline Skullcrusher
HarderPerforming the movement on an incline bench increases the shoulder flexion angle, stretching the long head further.
Cable Triceps Pushdown
EasierConstant tension with minimal elbow stress, though it trains the long head poorly. The natural companion movement.
Dips
HarderA compound movement that loads the triceps under bodyweight alongside the chest and shoulders, with far more total stimulus.
Frequently asked questions
Should I lower the bar to my forehead or behind my head?
Behind your head is generally the better option. It keeps tension on the triceps at the top rather than letting the bar reach a resting position over your face, increases the stretch on the long head, and most people find it more comfortable on the elbows. Lowering to the forehead is not wrong, just slightly less effective.
Are skullcrushers bad for your elbows?
They place more stress on the elbow than most triceps exercises, because the joint is loaded in a stretched position. That is manageable rather than dangerous: use an EZ bar, keep the load moderate, control the descent and stay in the 8–15 rep range. If your elbows still object, dumbbell or cable versions are usually well tolerated.
Why are skullcrushers called that?
Because the bar travels towards your head, and losing control of it has an obvious and unpleasant consequence. The name is a warning about load selection rather than a reason to avoid the exercise, with moderate weight and a controlled descent, it is no more hazardous than any other free-weight movement.
Are skullcrushers better than triceps pushdowns?
For the long head of the triceps, yes, the stretched position loads it far better than a pushdown, where the elbows are fixed at the sides and the long head is already shortened. Pushdowns remain better for constant tension, high volume and elbow comfort. They are complements, and most programmes should include both.
How much weight should I use for skullcrushers?
Moderate, enough for 8–15 controlled reps with your upper arms fixed and your elbows tracking forward. This is not a lift to load heavily. Because the elbow is stressed in the bottom position, the risk-to-reward ratio turns unfavourable quickly as the weight increases.
Hercules tracks every skullcrusher you log, shows you last session's numbers before you lift, and flags when your progress stalls.
Get it on Google Play