Whether you’re a competitive athlete or not, you’re probably not training primarily to boost your triceps size and strength. It’s not like max effort triceps extensions are going to be the next big competition lift. But that doesn’t mean your triceps aren’t crucial to your training. Whether you’re a competitive strength athlete or just enjoy the occasional bench pressing session on your lunch break, you need strong, well-developed triceps if you ever want to press heavy weight.
Why? The triceps assist you in all of the upper body lifts you see in powerlifting, strongman, weightlifting, and your average Tuesday in the gym. Strong triceps increase bench press strength, arm size, and overhead pressing abilities.
While you are technically training your triceps directly through pressing movements, adding more triceps isolation training will help improve your lockout on a wide variety of presses. You’ll also give your arms some serious sleeve-busting status. The dumbbell skull crusher is one of those triceps isolation moves that’s going to beef up your arms and your presses all at once.
- How to Do the Dumbbell Skull Crusher
- Benefits of the Dumbbell Skull Crusher
- Muscles Worked by the Dumbbell Skull Crusher
- Who Should Do the Dumbbell Skull Crusher
- Dumbbell Skull Crusher Sets and Reps
- Dumbbell Skull Crusher Variations
- Dumbbell Skull Crusher Alternatives
- Frequently Asked Questions
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How to Do the Dumbbell Skull Crusher
To perform the dumbbell skull crusher, you need a pair of dumbbells. You perform this exercise on a training bench or on the floor Using a bench helps to increase the movement’s range of motion, so that’s the version this guide will discuss.
Step 1 — Get Into Position
Grab a pair of dumbbells, one in each hand. Lie down on your back on a bench. Press the weights above you so that they are over your face rather than directly above your shoulders.
Coach’s Tip: By starting with your arms slightly back (closer to your face rather than at a perfect 90 degree angle with the ground), you place tension on your triceps, even in the top position.
Step 2 — Lower the Weights
Without letting your elbows flare outwards, bend them to lower your dumbbells to the sides of your face or to the outer edges of your forehead. The only joint that should move is your elbows. Lower the weights as low as you can go. The lower you go, the more stretch you give your triceps.
Coach’s Tip: Keep your elbows back as you bend them. Do not let them move more forward towards your chest.
Step 3 — Extend the Weights Upwards
Extend your elbows. Push your hands upwards to the start position. Avoid dropping your elbows so you don’t turn it into a chest press.
Coach’s Tip: Make sure to not bring the dumbbells back over your shoulders. Instead, extend your elbows fully with your hands over your face. That will keep tension on your triceps at all times.
Benefits of the Dumbbell Skull Crusher
You can use the dumbbell skull crusher to build triceps strength, add size to your arms, and assist in overall triceps development for pressing movements. No matter what your goals, you’ll likely find a good reason to work on your tris.
Build More Triceps Muscle
Your triceps accumulate a fair amount of training volume from overhead presses and benching. But because they’re smaller and less directly targeted by these bigger compound moves, your triceps are likely to become a limiting factor in those lifts. Moreover, it means that with presses alone, your tris — and your pressing numbers — are unlikely to reach their maximum growth potential.
By adding more triceps isolation exercises, you can boost your triceps training while saving your shoulders the stress of heavy pressing. You’ll be rewarded when your shirt sleeves start stretching because you’ve added quality, direct triceps training volume that won’t stress your shoulders.
Improve Lockout Strength
If you’ve hit a plateau with your bench or overhead presses, poor lockout strength might be why. You need strong triceps to lock out pretty much any pressing move. Without them, you won’t be able to get that last bit of power you need to bring your arms to full extension.
But the skull crusher directly strengthens your triceps without adding undue stress to your shoulders and chest. That means you can use it to build some serious lockout strength. This will reinforce heavy pressing movements like the bench press and overhead lifts.
Promote Elbow Health
Your elbows tend to get beat up with life and lifting. If you already tend to experience elbow pain, you might find the skull crusher uncomfortable. Using the dumbbell variation — instead of a curl bar or barbell — might help reduce that discomfort because you’ll have more freedom to adjust your arms according to your own limb length and needs. (That said, if it hurts in any configuration, it might not be the move for you.)
However, for folks who don’t experience discomfort or pain from the movement, dumbbell skull crushers can actually help make your elbow joints healthier. You’ll strengthen your connective tissues to better prepare them for heavier loading and overuse. Higher-rep training — like you might do with this isolation move — can help increase blood flow to muscles and connective tissues.
Muscles Worked by the Dumbbell Skull Crusher
The dumbbell skull crusher is a triceps isolation exercise. You’re really targeting your triceps in a big way with this one. If you’re feeling it anywhere else, this could be a sign that you are not performing this single-joint movement correctly.
Your triceps are composed of three different heads — lateral, medial, and inner. The skull crusher does a great job of developing your medial (long) and lateral heads. Your triceps are responsible for elbow extension, and the skull crusher attacks this exact joint action. Further, you’ll target your triceps long head, which is particularly crucial for building triceps size.
Who Should Do the Dumbbell Skull Crusher
Like other triceps movements — think triceps kickbacks, pushdowns, and overhead extensions — the skull crusher has a prime place at the triceps training table. Below, we will discuss how the dumbbell skull crushers could benefit various groups of trainees.
Pressing strength is a key must for all manner of competitive athletes. Powerlifters, strongman and strongwoman competitors, and weightlifters alike all need strong triceps and healthy shoulders to execute heavy lifts (and safely).
Adding triceps isolation exercises, in addition to already doing compound pressing moves, can help increase triceps muscle mass, elbow extension strength, and improve joint stability. All of these factors are a powerful recipe for creating stronger overhead lifts — and much bigger maxes.
It’s not just competitive lifters that can benefit from dumbbell skull crushers. Regular gymgoers can also use this move to increase arm size, triceps strength, and muscle mass. Although many beginners only train a few times per week, it is important to focus on compound movements to build muscle as efficiently as possible. Once you get stronger at these moves, adding in single-joint movements like skull crushers can provide an extra training stimulus to bring up weaker muscles or emphasize areas of growth.
Dumbbell Skull Crusher Sets and Reps
The triceps themselves are often trained with heavy loads indirectly. So if you’re looking for specific training adaptations from skull crushers, adjusting your load and volume will be key.
To Build Strength
If you are looking to build strength with the dumbbell skull crusher, you can do so by training with heavier loads in the five to 10 rep range for three to six sets.
Always use caution when training single-joint movements for strength, because you don’t want to overtax muscles (and the surrounding tendons, ligaments, and the joints) you’re already loading intensely with compound exercises. Still, when done properly, you can build triceps extension strength and mass with relatively heavy reps done with controlled speeds.
To Build Muscle
You can build muscle by training the dumbbell skull crusher in the eight to 15 rep range for three to six sets. Use moderately heavy weights and try to approach failure with your sets.
However, if you’re already performing a lot of heavy pressing in your program, you can opt to lighten the load and perform even more reps (think 15 to 25) to build both muscle and endurance.
Dumbbell Skull Crusher Variations
Changing your exercise angles or equipment can offer additional benefits to an already great movement. Varying your dumbbell skull crusher game can take your triceps training to the next level.
Incline Bench Dumbbell Skull Crushers
As the name suggests, you’ll perform the incline bench dumbbell skull crusher on an incline rather than a flat bench.
The incline increases your range of motion. Because this adds extra tension and loaded stretching to your triceps, you’ll stand to build even more muscle.
Dumbbell Floor Skull Crushers
You can perform the dumbbell skull crusher without a bench by lying on the floor. While increasing the range of motion is usually associated with increased muscle mass, partial range of motion moves can also make you stronger.
Reducing your range of motion can help you move more weight and improve your control at the bottom of the exercise. Plus, the smaller range of motion may help you out if your elbows don’t love skull crushers to begin with.
To make this move even more user-friendly, you might consider using one dumbbell (as in the accompanying video). Grasp either end of the dumbbell in each hand with your palms facing each other. That way, it’ll serve as a mini-barbell with a neutral grip so your elbows will automatically stay more tucked into your body.
Dumbbell Skull Crushers with Bands
To perform the dumbbell skull crusher with resistance bands, you take a single band and hold it in your hand (one hand has each end). Then you’ll grasp the dumbbell handles.
The middle of the band should be under the bench or anchor point so that when your hands extend upwards, you’re putting tension on the band. This adjustment will add accommodating resistance to the move.
The band will provide added resistance to the top of the movement, where it would get easier without a band. So, the tension on your triceps will remain more constant throughout the entire rep (instead of increasing toward the bottom and petering out at the top of the lift). With this extra resistance throughout the range of motion, you’ll seriously increase your time under tension and muscle-building capacity.
Dumbbell Skullcrusher Alternatives
If skull crushers hurt your elbows, there’s no need to force your way through them. Instead, try some of these alternatives.
Dumbbell JM Press
The dumbbell JM press is a skull crusher-like movement that allows your elbows to drop down towards your body as you perform the movement. By allowing your elbows to be next to your ribs, instead of pointed in the air, you decrease the amount of stress on your elbow joints while still training your triceps.
This can be helpful for lifters who struggle with elbow pain and discomfort during the skull crusher. You won’t be showing as much love to the long head of your triceps, but you’ll still be targeting the muscle in a big way.
Dumbbell French Press
The dumbbell French press is another single-joint movement that isolates your triceps. To do this, you start with the dumbbells in the top of the bench press position. Then, you’ll flare your elbows out to the sides of your body as you lower the end of the dumbbell to your chest.
At the bottom of the French press, your elbows should be flared out 90 degrees to the sides, with your thumbs pointing towards your chest. Extend your elbows and return the weights back to the starting position, and repeat. This move offers a different angle through which to train your triceps, and can add some nice variety to your routine.
Neutral-Grip Dumbbell Bench Press
The neutral-grip dumbbell bench press is a bench press variation that targets your triceps and chest. While this is a compound move rather than a triceps isolation exercise, it does help to develop stronger triceps and increase elbow extensor strength.
With your hands in a neutral grip — with your palms facing each other — you’ll take tension off of your shoulders so that you can dial in more focus onto your triceps.
The dumbbell skull crusher is a triceps isolation exercise that helps build stronger triceps, increases muscle mass, and reinforces the elbow extension necessary for pressing movements. While your triceps get a fair amount of training volume indirectly through compound pressing movements like bench presses, dips, and overhead lifts, adding direct triceps isolation exercises — like the dumbbell skull crusher — into your training can further enhance muscle growth and lockout performance.
The dumbbell skull crusher is a fairly straight-forward movement. That said, they can cause some discomfort and pain when done improperly — or if the elbows themselves are a little beat up. So, it’s worthwhile running through some common questions about the dumbbell skull crusher.
Is the skull crusher bad for your shoulders?
You should not feel your shoulders in this movement, as it is an isolation movement specifically for the triceps. If you are feeling your shoulders, it’s likely that you’ve got an incorrect set-up. Try bringing your elbows more perpendicular to the ground and keeping them there. If that doesn’t work, lower the load.
What can I do if the dumbbell skull crusher hurts my elbows?
If you experience elbow pain or discomfort, try performing the JM press or other alternatives. If this is an issue with elbow tendonitis or chronic nagging joint pain, you will want to back off from loading and train the movement very lightly, if at all. It’s advisable to have any joint pain looked at by a trained professional.
Are dumbbell skull crushers better than barbell skull crushers?
No. The dumbbell version of this lift is neither better nor worse, just different. However, using dumbbells might go easier on your elbows because it frees up a more unique range of motion depending on your body type and limb lengths.
Featured Image: MDV Edwards / Shutterstock