Dumbbell Skull Crusher

The dumbbell skull crusher is a movement that poses an incredible strength requirement. 

Two impactful ways to push a muscle are with resistance and range of motion, and the skull crusher aggressively blends the two nicely. 

Whether you have strength, aesthetics, or performance goals, the dumbbell skull crusher is great to have in your training repertoire.

How To Do

  1. To set up, sit on one end of a bench with your legs on either side. Hold a pair of dumbbells on your thighs with a neutral grip (Palms facing each other).
  2. Lie back with your head near the edge of the bench. Press the dumbbells above your chest and face your palms toward each other. 
  3. Bend your elbows and slowly lower the dumbbells past the top of your head. 
  4. Straighten your arm toward the sky and squeeze your triceps.
  5. Repeat steps 3 and 4 until you’ve completed the optimal number of repetitions.

Tips From Expert

  • Warm up with non-overhead extension exercises (e.g., push-ups, press-downs, dips) to avoid elbow discomfort.
  • If you feel elbow pain, the weight may be too heavy or you may need a longer warmup. 
  • Beginners should choose weights that feel easy to moderately challenging at first.
  • Avoid lifting too fast; control the weights to ensure each side receives an even stimulus. 
  • Be careful not to hold or lift the weights over your face as it’s dangerous. 
  • Angle your arms back and lower the weights behind your head for a better triceps stretch. 
  • You can also perform this exercise by holding one dumbbell in both hands.

Optimal Sets and Reps

The dumbbell skull crusher is an instant impact movement, but volume and reps vary depending on what result you are aiming for.

Training Type Sets Reps
Strength Training 3–5 6–8
Hypertrophy 3–6 8–12
Endurance Training 2–3 15–20
Power Training 1–3 1–5
Optimal Sets & Reps of Dumbbell Skull Crusher

How to Put in Your Workout Split

The dumbbell skull crusher is a serious advantage to any strength program. For strength, endurance, and muscle building, several different workout splits can be used:

  • Push/Pull — Include dumbbell skull crushers on your push days. Be sure to do them after your big compound lifts like the bench press, as the tricep fatigue can hamper your high-loaded exercises.  
  • Total Body — If your program is designed to work your full body every day, these should be programmed no more than two to three times per week. Make sure that on other days you emphasize muscle recovery and utilize less intense methods for your arms. 
  • Single Muscle Group — If your routine features just one muscle group per day, you will likely be limited in rear arm weekly frequency. The dumbbell skull crusher should be programmed on those days for high volume in terms of set and number. 

Light loads and lower volumes should be considered for splits with three or more weekly arm days such as the total body. Those with just a couple of weekly upper body days may feature higher loads and volumes.   

Primary Muscle Groups

Triceps Long Heads

Large muscles located at the back of your arms between your shoulder and elbow. Most outside portion of the tricep.

Triceps Long Head 

The long head of the triceps is the one you see along the inner back half of the upper arm. 

It is the medial side of the common horseshoe look that is used to describe the rear arm musculature. 

This muscle produces the greatest extension force when the elbow is closer to the body. Tricep pushdowns are a great example of this.

Secondary Muscle Groups

Triceps Lateral Heads

Muscles located on the back of your arm between your shoulder and elbow.

Triceps Medial Heads

Small muscles located at the back of your arms. Deep to the triceps long heads between the shoulder and elbow.

Triceps Lateral Heads 

The lateral head of the triceps is featured on the outer half of the rear upper arm and aids most strongly in elbow extension when the arm is at or above 90 degrees away from the body.

Exercises with this arm position are those such as chest and overhead shoulder presses.

Triceps Medial Heads 

The medial head of the triceps tends to mimic the elbow extension activity level of the lateral head in all arm positions.

With that said, it also produces its highest extension force when the elbow is below 90 degrees and closer to the body.  

Equipment

Dumbbells

Flat Bench Without Rack

Dumbbells

You can use these for a wide range of unilateral and bilateral exercises. Avoid using momentum to lift. Ensure a secure grip to prevent drops.

Flat Bench Without Rack

This is great for pressing and pulling movements. Ensure the safety catch is firmly locked in. If you can't find this bench, use one with a rack for barbell exercises.

Variations

Exercises that target the same primary muscle groups and require the same equipment.

Ez Bar Lying Triceps Extension

Barbell Lying Triceps Extension

Dumbbell Standing Overhead Tricep Extension

Dumbbell Standing Single-Arm Tricep Kickback

Tricep Dumbbell Kickback

Cable Tricep Kickbacks

Kneeling Overhead Tricep Extension

Dumbbell Tate Press

Alternatives

Exercises that target the same primary muscle groups and require the different equipment.

Triceps Dip

Diamond Push-Up

Overhead Triceps Stretch

Chair Tricep Dips

Narrow Push-Ups

Crab Walk

Kneeled Diamond Push-Ups

Ring Dip

Cable Tricep Pushdown

Overhead Cable Tricep Extension

Who Should Do?

People Who Want Bigger Triceps

The intensity and high resistance feel of the dumbbell skull crusher lends perfectly to what’s required to stimulate muscle growth. 

This type of challenge combined with a great range of motion is sure to promote muscle. 

Athletes

A variety of sports involve athletic movements where upper body push and elbow extension are crucial. 

Many of these movements are also required to have speed and power for maximum force. The strength improvements afforded by the skull crusher can be instrumental.  

Those Needing A Bench Press Boost  

Incorporating the dumbbell skull crusher into your training can have a positive effect on other exercises in your routine. 

Any pushing movements, like the barbell bench press, stand to largely improve from the gains seen through doing this movement.  

Who Should Not Do?

People With Elbow Issues

Those with weakness or pain in the elbow should avoid the dumbbell skull crusher exercise. 

The elbow angles and ranges of motion that best suit this movement produce forces that are problematic for unhealthy elbow joints. 

Those Not Training For Hypertrophy 

The dumbbell skull crusher is most suitable for building strength and muscle due to the heavy workload it places on your triceps.

The joint pressure associated with this exercise is not worth the effort if hypertrophy is not a training objective. 

Individuals With Shoulder Dysfunction 

Positioning for the skull crusher exercise requires flexion of the shoulder that approaches an overhead position. 

Individuals with forward rounded posture and shoulder impingement may find this position irritating despite the fact it is not an upright exercise.  

Benefits Of The Dumbbell Skull Crusher

Builds Triceps Mass

Movements that extend the elbow against gravity, such as dumbbell skull crushers, cause significantly more muscle gain compared to neutral arm exercises like triceps pushdowns.

Enhances Lockout Strength

This refers to the second half phase of a chest press repetition. 

Finishing the repetition or locking out, uses your triceps much more than other arm muscles. 

So, a tricep-isolating move like the dumbbell skull crusher can undoubtedly get you to lock out more easily.

Improves Elbow Health

Anything that does well for strengthening can surely improve a weakened muscle, or one in a post-injury state. 

The stretch-loaded quality of the skull crusher provides impactful strengthening effects for an elbow needing to restore function. 

Frequently Asked Questions

Are dumbbell skull crushers effective?

Yes. Dumbbell skull crushers provide a unique combination of loaded muscle stretching and complete triceps muscle activation.

What angle should dumbbell skull crushers be?

Skull crushers should be performed lying down on a flat surface (e.g. gym bench, floor). This allows gravity to help push your triceps into a deeper stretch compared to other training angles.

Should skull crushers be heavy or light?

It depends on your training experience, goals, and joint health. We recommend choosing weights that challenge you in the 8-15 rep range for optimal muscle gains and joint health.

Why does my elbow hurt when I do these?

If you feel pain in your elbow doing the dumbbell skull crushers, it’s likely for two reasons: Either the weight needs to decrease, or you are stretching the movement too deeply which should shorten the range of motion.

Resources

Endomondo.com refrains from utilizing tertiary references. We uphold stringent sourcing criteria and depend on peer-reviewed studies and academic research conducted by medical associations and institutions. For more detailed insights, you can explore further by reading our editorial process.

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  2. Sumiaki Maeo, Wu, Y., Huang, M., Sakurai, H., Kusagawa, Y., Sugiyama, T., Hiroaki Kanehisa and Tadao Isaka (2022). Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position. EJSS/European journal of sport science, [online] 23(7), pp.1240–1250. doi:https://doi.org/10.1080/17461391.2022.2100279.
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