MariposasHow to Do the Skull Crusher
By Zachary, builder of Mariposas · Reviewed against published exercise-science sources (references)
· Last updated June 2026
The barbell skull crusher earns its place in serious training programs because it loads the triceps through a long range of motion with the elbows overhead, a position that stretches the long head of the muscle in a way flat pressing and pushdowns simply cannot replicate. That long-head stretch under load is what drives hypertrophy in the thick, meaty portion of the upper arm that makes arms look developed from every angle. Because it isolates the triceps without the shoulders and chest sharing the burden, weaknesses get exposed fast and fixed faster. Track every set and see your progress over time by logging this lift free in the Mariposas app.
How to do it
- Lie flat on a bench and grip a barbell with an overhand grip slightly narrower than shoulder width, so roughly six to ten inches between your index fingers, depending on your wrist comfort.
- Press the bar to full arm extension directly over your chest, then shift it back so it floats over your forehead, not your sternum. This vertical alignment keeps constant tension on the triceps rather than turning the movement into an accidental close-grip press.
- Plant your feet flat on the floor, brace your core lightly, and press your upper back into the bench so your torso stays completely still throughout the set.
- Keeping your upper arms fixed and angled very slightly back toward your head, hinge only at the elbows and lower the bar in a controlled arc toward your forehead or the bridge of your nose. The bar should travel in an arc, not straight down.
- Stop the descent when the bar is roughly an inch above your forehead or skull, which is how the lift got its name. Do not let the bar actually make contact, and do not rush this portion.
- Without flaring the elbows outward or letting the upper arms drift forward, drive the bar back up through the same arc by extending the elbows forcefully until your arms are fully locked out overhead.
- Squeeze the triceps briefly at the top of each rep before beginning the next descent. That brief pause helps confirm that the elbows have fully extended and the triceps are doing the work.
- After the final rep, press the bar toward your chest and rack it conventionally, or lower it to your chest and have a spotter assist. Do not try to re-rack from the overhead position with fatigued arms.
Form cues
- Elbows stay in, not winged out.
- Upper arms don't move. Only the forearms travel.
- Lower slow, press fast.
- Bar floats over the forehead, not the chest.
- Squeeze the lock-out every rep.
Common mistakes
- Letting the upper arms drift forward as the bar descends: this silently converts the movement into a close-grip press hybrid and removes the stretch on the long head. Keep a mental image of your elbows as two fixed hinges bolted to the ceiling.
- Flaring the elbows wide: it dumps load off the triceps and shifts stress onto the elbow joint itself, which becomes painful quickly. Actively think about keeping the elbows pointed toward the ceiling and roughly shoulder-width apart.
- Using too much weight and cutting range of motion short: stopping the descent too early defeats the entire purpose of choosing this exercise over a pushdown. Go lighter, touch the full range, and earn the stretch.
- Bouncing or rushing the eccentric: swinging momentum into the bottom of the movement creates a jarring force on the elbow joint at its most vulnerable angle. Controlled lowering over two to three seconds is the standard most experienced lifters use.
- Starting with the bar over the chest instead of the forehead: this common setup error means the bar ends up traveling past horizontal at the bottom, turning the exercise into something between a pullover and a press. The bar should start directly over your face so the descent stays in a true triceps arc.
Why do the Skull Crusher?
- The overhead elbow position places the long head of the triceps under a meaningful stretch, and research on muscle hypertrophy consistently points to loaded stretching as a strong driver of growth. Few other triceps exercises achieve this as effectively with a free weight.
- Because the shoulders and chest contribute almost nothing here, this movement builds direct triceps strength that tends to carry over to the lockout portion of bench press and overhead press, the phase where those lifts most commonly fail.
- The barbell version allows progressive overload in small increments over a long training career, which makes it a reliable builder for lifters who have exhausted easy gains on machine and cable variations.
- Training the triceps in an isolated fashion like this helps correct the imbalance that develops when someone presses a lot but rarely works the arms directly. Fuller, more evenly developed triceps also provide better passive elbow stability during compound pressing.
Skull Crusher variations
- EZ-Bar Skull Crusher
- The angled grip of an EZ-bar reduces wrist and elbow strain for lifters who find the straight barbell uncomfortable, making it a practical first choice for anyone new to the movement or working around a minor wrist issue.
- Dumbbell Skull Crusher
- Using dumbbells lets each arm move independently, which can correct side-to-side strength imbalances and allows the wrists to rotate to a slightly more natural angle during the arc.
- Close-Grip Bench Press
- A useful regression when someone lacks the elbow stability or mobility to hold the skull crusher position, since the bar travels to the chest and the upper arms stay closer to the body, reducing stress at the elbow.
- Incline Skull Crusher
- Performing the movement on an incline bench increases the overhead stretch on the long head even further and is typically used by intermediate to advanced lifters chasing maximum long-head stimulus.
How to program it
Most lifters program skull crushers in the six to twelve rep range, where the combination of mechanical tension and stretch-mediated hypertrophy tends to produce the best triceps growth. Because the elbow joint is under load in a compromised position, the exercise almost universally appears toward the end of an upper body or push session rather than at the start, after the shoulder and chest compound lifts are done. Sets of eight to twelve are common for hypertrophy-focused training blocks, while powerlifters and strength athletes sometimes use heavier loading in the four to six rep range to build raw triceps lockout strength. Anywhere from two to four working sets per session is the typical range seen in structured programs.
Skull Crusher alternatives
FAQ
- Why do my elbows hurt during skull crushers?
- Elbow pain on this movement usually has two sources. The first is flared elbows, which loads the joint laterally instead of keeping force running through the bone. The second is too much weight with too little control, especially at the bottom of the arc where the joint is at its most vulnerable angle. Try an EZ-bar instead of a straight bar, reduce the load, and focus on actively pulling the elbows inward throughout the set.
- Skull crushers vs. tricep pushdowns: which builds more mass?
- They build the triceps differently. Pushdowns work the triceps in a shortened position, which is good for peak contraction. Skull crushers work the muscle through a stretch, which targets the long head more directly. Most experienced lifters use both rather than choosing one, because the long head makes up the bulk of triceps mass and responds well to the overhead loading that skull crushers provide.
- How close should my grip be on the bar?
- A grip roughly six to ten inches wide between the index fingers is standard. Going narrower than that increases wrist stress without adding triceps stimulus. Going wider starts to recruit the chest and shoulder and defeats the isolation purpose. An EZ-bar naturally places your hands in a comfortable narrow position if the straight bar bothers you.
- Can I do skull crushers without a spotter?
- Yes, but with care. Because the bar is held over your face at a fatigued angle, failure is more dangerous here than on a standard bench press. Use a weight you are confident completing all reps with, and if you are training to failure, do so on a cable or dumbbell variation instead. Some lifters transition into a close-grip press at the very end of a skull crusher set to safely move the bar to the chest if they feel close to failure.
- Should the bar touch my forehead or go behind my head?
- Neither, exactly. The most common target is an inch or so above the forehead or bridge of the nose, without contact. Lowering behind the head is a variation called a French press or overhead triceps extension, which increases the stretch further but also shifts the balance point and increases stress on the shoulder. The standard skull crusher stops in front of the face, controlled, never touching.