Barbell Skull Crushers: A Complete Guide | How to Build Big Triceps!

Barbell Skull Crushers

Also known as the lying triceps extension, the skull crusher is an effective exercise for developing the triceps. If you want to build bigger, stronger triceps, the barbell skull crusher is for you!

Muscles Worked By Barbell Skull Crushers

Primary Muscle Groups:

The skull crusher’s name basically describes the worst case outcome of the exercise. While this may sound daunting, the triceps are here to ensure that your skull remains intact during the barbell skull crusher.

The triceps muscle is comprised of three “heads:” the long, medial, and lateral head. While the lying triceps extension works all three heads of the muscle, it especially targets the long and lateral heads of the triceps.


Secondary Muscle Groups:

Although the tricep barbell skull crusher is an isolation exercise, several other muscle groups are secondarily worked. Your anterior and posterior deltoids in your shoulders contract to stabilize your arms. In addition, the latissimus dorsi, the largest muscle of your back, plays a role in stabilization as well. 

Barbell Skull Crusher Benefits

1. Stronger Triceps

The barbell skull crusher is one of the premier exercises proven to strengthen your triceps muscle. Stronger triceps are crucial for completing so many other upper body exercises. Without strong triceps muscles, it will be difficult to properly train your chest and shoulders.

While the exercise motion of the skull crusher is less functional than other exercises such as the overhead tricep extension and the tricep dip, the barbell skull crusher will still improve your performance in a variety of exercises at the gym. 

2. Triceps Isolation

The lying triceps extension is an isolation exercise. This means that unlike other exercises such as the push-up or bench press, the barbell skull crusher specifically targets the tricep muscle. This is especially important for bodybuilders, athletes, or anyone else seeking to focus on increasing the size of the triceps.

Considering the triceps makes up more than half of the mass of your arm, there is room for major gains with targeted training. 

3. Minimal Stress On The Joints

Throughout the tricep barbell skull crusher, the weight remains over your head and your wrists stay in a relatively neutral position. Some people find heavier straining exercises like push-ups or weighted dips uncomfortable for their wrists and shoulders.

If this sounds like you, try out the barbell skull crusher and take the tension off of your joints!

How To Do Barbell Skull Crushers 


For this exercise, you will need a barbell and some weights. There is also an option to use a flat bench. 


a) Lie down on the ground or a flat bench with your feet planted firmly on the ground.

b) Hold the barbell above your chest with an overhand grip and engage your core.


a) With your elbows in a fixed position, hinge your elbows to slowly bring the barbell down just over the top of your forehead. 

b) Contract your triceps to extend your arms back into the straight position at the top. 

c) Repeat this motion for your desired number of reps. 


If you are new to the lying triceps extension, choose a light weight to begin and complete 3-4 sets of 15-18 reps. If you are more comfortable with the form, add some more weight and stick to the 8-12 rep range for 3-4 sets. 

Barbell Skull Crusher Mistakes

1. Flaring The Elbows 

Many weightlifters tend to flare out their elbows when learning how to do barbell skull crushers. Due to the fixed position of the wrists, some flaring of the elbows is inevitable when completing this exercise.

However, excessive flaring risks injury to the shoulders and removes tension from the triceps. Make sure to keep your elbows slightly in to practice proper form.

2. Excessive Movement Of The Elbows/Shoulders

During the lying triceps extension, you want to make sure your elbows are in a fixed position. Often times, people tend to rock their shoulders back as the weight comes down. This forces the elbows to shift backwards as well.

While some movement is natural, too much movement will force your lats to activate to bring the barbell upwards. If you want to solely train your triceps, keep those elbows and shoulders in a stationary position. 

3. Arching Your Back

Arching your back during the lying triceps extension compromises the stability of your body positioning while completing this exercise. Instead of arching your back, place your feet firmly against the ground, engage your core, and keep your back flat against the bench or ground. 

Barbell Skull Crusher Variations

1. Bodyweight Skull Crushers

No equipment? No problem! You can do a skull crusher with just your body weight. First, set up in a plank position with your hands together. Then contract your triceps and push your body off the ground and slightly backward.

Return to the plank position and repeat!


2. Dumbbell Skull Crushers

The dumbbell skull crusher is another fantastic variation of the barbell skull crusher. Instead of setting up a barbell and adding on weights, some people opt for dumbbells for the sake of convenience.

Others find that holding dumbbells with a neutral grip is more comfortable than holding a barbell with an overhand grip.

For whatever reason you choose, the dumbbell skull crusher can help you make major tricep gains as well!

3. 1-Arm Skull Crushers

You can also use the skull crusher to train your arms individually to fix any muscle imbalances in your arms. Keep your core engaged for stability during this variation!


Barbell Skull Crusher Alternatives

If you enjoyed the barbell skull crusher, check out these triceps exercises to improve your triceps training:

1. Tricep Dumbbell Kickbacks

The tricep dumbbell kickback is a mass building tricep isolation exercise. To begin, grab a pair of dumbbells with your palms facing each other. Assume a standing position with your feet roughly hip width apart.

Keeping your back straight, hinge at the waist until your back is roughly parallel to the floor. Bring the dumbbells close to your chest. Bend your arms so that your elbow forms a 90 degree angle with your forearm. 

With your elbows in a fixed position, contract your triceps to bring the dumbbells behind you until your arms are fully extended. Squeeze your triceps at the top of the rep, pause for a moment, then slowly return to the starting position. Repeat this motion for your desired number of reps!


2. Tricep Pushdown 

The triceps pushdown is another powerful triceps isolation exercise for people of all fitness levels. To begin, face a pulley machine with your feet shoulder width apart and make sure the attachment hangs at chest height.

Hold your chest high, bring your shoulder blades together, and bend slightly forward to initiate the exercise.

With your elbows tucked in tight to your sides, bring the attachment down until your arms are fully extended. Pause at the bottom of the repetition and flex your triceps for maximum contraction. Make sure you maintain a neutral wrist position the entire time.

Slowly release the weight and return to the starting position. Repeat!

3. Overhead Triceps Extension (With Rope)

The overhead triceps extension strengthens the long head of your triceps. Set up a pulley machine with the rope attachment at roughly hip level. Facing away from the machine, grab the rope with both hands and bring the bottom of the rope behind your head with your arms bent.

As you extend upwards, pull the rope apart and straighten your arms. Squeeze your triceps hard at the top of the rep and slowly return to the starting position. Repeat!



Looking For A Complete Triceps Workout?

Follow along to this intense barbell triceps workout! 

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.mike kenlerExercises & fitness tips