TricepsBarbell or EZ barIntermediate

How to Do Skull Crushers

By Bryan Alger, Co-Founder of Gravitus

· Updated Sep 30, 2026

A skull crusher is a lying triceps extension with a barbell or EZ bar. Lie on a flat bench, keep your upper arms still and bend your elbows to lower the bar to your hairline or just behind your head. It trains all three heads of the triceps. Most lifters do 3 to 4 sets of 8 to 15 reps.

Sets x reps 3-4 x 8-15

Median 10-rep weight 5525 lbkg men 3014 lbkg women

Muscles Triceps, all three heads

Lower to Your hairline or behind your head

Skull Crusher start and bottom positions

1Start. Lie on a flat bench with your head near the end. Hold the bar overhand with straight arms over your shoulders, tilted slightly back toward your head.
2Bottom. Bend your elbows and lower the bar past your forehead to just behind your head, then press it back to the start.

Watch 2 video demonstrations

Video 1 of 2

Technique

How to do a skull crusher

Sit on the end of a flat bench with the bar on your thighs. Hold it overhand on the inner angled grips of an EZ bar, or at shoulder width or a little narrower on a straight bar.
Lie back until the top of your head is at the end of the bench, holding the bar at your chest. Press it up over your shoulders and plant your feet.
Tilt your upper arms back toward your head, about 20 degrees past vertical, so the bar sits over your forehead. Keep your elbows shoulder-width apart.
Keep your upper arms still and bend only at the elbows. Lower the bar over 2 seconds to your hairline, or past the top of your head if it clears the bench.
Straighten your elbows to press the bar back to the start. Finish every rep with straight arms.
After the last rep, bring the bar down to your chest, then sit up with it on your thighs.

Setup

To your forehead or behind your head?

Both work, and behind your head is the longer rep. With the bar lowered to your hairline, your forehead stops it before your elbows are fully bent. Lowered behind your head, the bar clears your face and your elbows bend further, so the triceps ends the rep more stretched.

To make room, lie with the top of your head at the end of the bench and hold your upper arms tilted back toward your head for the whole set. Tilt them a little more if the bar still hits your head. The same tilt keeps the top of the rep loaded; our dumbbell skull crusher guide charts how the arm angle moves the hard part of the rep.

What to do

Go behind your head if your elbows and shoulders are comfortable there, and stop at your hairline if it pinches. No study has compared the two bar paths. In a 12-week study, overhead extensions, which stretch the long head more, grew the triceps 1.4 times more than pushdowns (Maeo 2023).

Gravitus data

How much weight should you use for skull crushers?

On Gravitus, the median man lifts 55 lb (25 kg) for 10 reps on the skull crusher, and the median woman 30 lb (14 kg).

Men, typical 55 lb for 10 reps

Most lift: 45 to 70 lb
Top 10% lift: 90 lb or more
Starting out: under 45 lb

Women, typical 30 lb for 10 reps

Most lift: 22.5 to 35 lb
Top 10% lift: 45 lb or more
Starting out: under 22.5 lb

Men, typical 25 kg for 10 reps

Most lift: 20 to 32.5 kg
Top 10% lift: 40 kg or more
Starting out: under 20 kg

Women, typical 14 kg for 10 reps

Most lift: 10 to 16 kg
Top 10% lift: 20 kg or more
Starting out: under 10 kg

One-rep max / 10-rep weight, rounded to 5 lb (2.5 under 40). From 11,222 men and 1,467 women who log the skull crusher on Gravitus, computed Oct 4, 2026 (Brzycki). Methodology
Percentile	Men	Women
25th	60 / 45 lb	30 / 22.5 lb
Median	75 / 55 lb	40 / 30 lb
75th	95 / 70 lb	45 / 35 lb
90th	120 / 90 lb	60 / 45 lb

One-rep max / 10-rep weight, rounded to 2.5 kg (1 under 20). From 11,222 men and 1,467 women who log the skull crusher on Gravitus, computed Oct 4, 2026 (Brzycki). Methodology
Percentile	Men	Women
25th	27.5 / 20 kg	13 / 10 kg
Median	35 / 25 kg	18 / 14 kg
75th	42.5 / 32.5 kg	20 / 16 kg
90th	52.5 / 40 kg	27.5 / 20 kg

These are total bar weights for a barbell or EZ bar. An empty EZ bar weighs 15 to 25 lb (7 to 11 kg) depending on the make, so count it when you compare. The dumbbell version is logged per hand, at about half the bar weight.

Setup

Which bar and grip to use

Palms angled inEZ bar, inner gripsThe default. The bends turn your palms partly in, which most lifters find easier on the wrists.

Palms downStraight barWorks the triceps the same. Use it if your wrists and elbows are fine with it.

Grip widthShoulder width or a little narrowerYour forearms run parallel. Much closer bends your wrists; much wider flares your elbows.

Palms toward youReverse gripHarder to hold, so most lifters go lighter. It does not shift work to another head.

No study has compared skull crusher grips. The triceps attaches to the ulna, the forearm bone that stays put when you turn your palm, so the grip changes how your wrists and elbows feel, not which head does the work.

Anatomy

Muscles worked

Triceps, all three headsStraighten the elbow. The long head also crosses the shoulder, so tilting your upper arms back stretches it more.

Primary

Forearms and gripHold the bar and keep your wrists straight.

Secondary

Lats, shoulders, coreHold your upper arms in place and keep you still on the bench.

Stabilizer

Research

What the research says

Skull crushers grow the part of the triceps the bench press misses. In Brandão 2020, 43 young men trained for 10 weeks with the bench press, the lying barbell triceps press (a skull crusher), or both. The triceps grew significantly only in the groups that did the skull crusher. The long head grew more in those groups, and the lateral head grew more in the groups that benched.

Three common claims the research does not back:

A close, wide or reverse grip works a different head. The triceps pulls on the ulna, which does not turn with your palm. A wide grip flares your elbows and brings in the chest and shoulders; it does not move work between the heads.
An EZ bar works the triceps better. It is easier on the wrists for most lifters. The triceps does the same job on either bar.
Lowering behind your head hurts your shoulders. No study shows it. Your arms stay well short of overhead, so your shoulders bend less than in an overhead extension. If it pinches, stop at your hairline.

Compare

Skull crusher vs dumbbell skull crusher vs close-grip bench press

Attribute	Skull crusher	Dumbbell skull crusher	Close-grip bench press
Joints moving	Elbows	Elbows	Elbows and shoulders
The weight goes	To your hairline or behind your head	Beside your head	To your lower chest
Each arm	Shares one bar	Works on its own	Shares one bar
Gravitus lifters log	Less than half the close-grip bench	About half the bar in each hand	The most weight of the three

Verdict

Do a press and a skull crusher. In Brandão 2020 the bench press grew the lateral head more and the skull crusher the long head, and the triceps grew significantly only in the groups that included the skull crusher. Swap the bar for dumbbells if a bar bothers your wrists.

Programming

Sets, reps and progression

3-4Sets

8-15Reps

0-2Reps left

Stop each set 0 to 2 reps short of failure. Sets taken close to failure build muscle across a wide range of reps (Schoenfeld 2021), so pick a range you can keep strict. Put skull crushers after your main press, when the triceps is already warm.

A loadable bar goes up 5 lb (2.5 kg) at a time with the smallest plates on each side, and fixed EZ bars usually jump 10 lb (5 kg). Add reps first: when every set reaches the top of your range, add the smallest jump and drop back to the bottom of the range.

Form

Common mistakes

Upper arms drifting toward your feetThe top of the rep goes slack and the lift turns into a close-grip press. Keep your upper arms tilted back toward your head.
Stopping with your elbows at 90 degreesYou skip the stretched part of the rep. Lower to your hairline or past your head every rep.
Elbows flaring wideYour chest and shoulders start to help. Bring your grip to shoulder width, and go lighter if they keep drifting out.
Wrists bent backThe bar rolls toward your fingers and your wrists take the load. Keep the bar low in your palm with your wrists straight.
Head in the middle of the benchThe bench blocks the bar behind your head. Slide up until the top of your head is at the end.
Sitting up with the bar over your faceBring it to your chest first, then to your thighs as you sit up.

Variations

Skull crusher variations

EZ-bar skull crusherThe same lift on an EZ bar. Some lifters log it as its own exercise in Gravitus.

Dumbbell Skull CrusherA dumbbell in each hand, lowered beside your head. Each arm works on its own.

Reverse-grip skull crusherPalms toward your face. Harder to hold, the same triceps work.

Decline skull crusherHead below your hips, which tilts your arms back from vertical and keeps the top of the rep loaded.

JM PressHalf skull crusher, half close-grip press. The bar comes down toward your chin as your elbows travel toward your feet, so you can go heavier.

Cable skull crusherLying with your head toward a low pulley. The cable pulls toward the stack, so the top of the rep stays loaded.

Smith machine skull crusherThe bar runs on rails and you can rack it at any point, which helps when you train alone.

Overhead Dumbbell Tricep ExtensionOne dumbbell behind your head, seated or standing. The most long head stretch.

FAQ

Questions people ask

What muscles do skull crushers work?

All three heads of the triceps. Your forearms hold the bar, and your lats and shoulders keep your upper arms in place.

What is the best grip for skull crushers?

The inner grips of an EZ bar, or a straight bar with your hands at shoulder width or a little narrower, so your forearms run parallel. A closer, wider or reverse grip does not change which head works.

Should skull crushers go to the forehead or behind the head?

Either. Behind the head is the longer rep and stretches the triceps more, if the bar clears the bench and your elbows are comfortable. To the hairline is shorter and easier to control.

EZ bar or straight bar for skull crushers?

An EZ bar for most lifters. The angled grips turn your palms partly in, which is easier on the wrists. A straight bar works the triceps the same if it is pain-free.

Is skull crusher better than close grip bench press?

They do different jobs. In Brandão 2020 the skull crusher grew the long head more and the bench press the lateral head, so doing both trains the whole triceps. The close-grip bench moves more than twice the weight.

Are skull crushers push or pull?

Push. You press the bar away by straightening your elbows, so they fit on a push day or an arm day.

How much should I be able to lift with skull crushers?

For 10 reps, the median on Gravitus is 55 lb (25 kg) for men and 30 lb (14 kg) for women. The strongest quarter lifts 70 lb (32.5 kg) and 35 lb (16 kg) or more.

Gravitus See where your skull crusher ranks

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References