How to do Skull Crushers



Want to learn how to do Skull Crushers (sometimes spelled skullcrushers) with perfect form? We’ve created a handy step-by-step guide with everything you need to know to perfect this great triceps workout.


There are many variations to skull crushers, however, we are going to walk through the most common variation and everything you need to do for the best form and benefits when conducting this exercise.

  1. To start you’ll need to use a flat gym bench, lying on your back with legs to either side or resting comfortably on the footrest.

  2. Get into your starting position by holding a dumbbell of your preferred weight in both hands, extended straight up above your chest and with your fists in a vertical position.

  3. Move the dumbbells down towards the back of your head by bending your elbows, trying to keep your upper arms straight and at a right angle to your body.

  4. Continue lowering the dumbbells behind your head until the top lines up with the edge of the bench. You can stay a little higher if this is too difficult.

  5. Now bring it back to the starting position by reversing your movement, ending with the dumbbells once again extended in a straight line up from your chest.

  6. Try to avoid locking your arms at the starting position.

Do's and Don'ts

  • DO keep your elbows tucked in towards the body.

  • DON’T lock out your arms.

Like we said, there are loads of different variants to skull crushers that vary in the type of weights used and exact movements. The steps above will prepare you for the foundation of the exercise. If you’d like to explore more arm toning exercises and upper body workouts please browse our exercise guides.


Skull Crushers are a series of exercises geared towards building upper arm strength, the more technical name is supine or lying triceps extensions. There’s no single way to do a Skull Crusher, but most popular variants focus on weights and elbow extensions, and primarily target the triceps. They’re best summarised as being single-arm, overhead dumbbell extensions, and the scary-sounding name refers to where the weight will land if it falls. But don’t worry – if you follow the instructions above you will be able to perform the skull crusher exercise safely.


Skull crushers are a great way to strengthen your upper arms using easily accessible equipment and a simple technique. But if you need guidance, get in touch with one of our friendly personal trainers at your local Gym to help you perfect your form.

Dumbbell Tricep Exercises
Read more
Dumbbell Bicep Curl
Read more
Chin ups exercise
Read more
Shoulder Exercises
Read more

Other Exercises

How to do a Dip
Read more
How to do Box Jumps
Read more
How to do a Bear Crawl
Read more
How to do Bent Over Row
Read more
* Offer available at selected sites only. See Terms & Conditions for further details. ** 24 hour access not currently available at all Gyms. Please see individual Gym pages for further details. ⨥Applicable terms, conditions and joining fees may apply. © 2024 The Gym Group.