Lying Dumbbell Tricep Extension

By: Jeremy Fox, CNC, CPT – Published: February 8, 2023

Lying dumbbell tricep extensions are a great exercise for building your upper arms. And this basic movement only requires a bench and some dumbbells.

But the dumbbell variation can be tricky to master at first. So I’ll give you some pointers on properly doing dumbbell lying tricep extensions with good form and technique.

What Is a Lying Dumbbell Tricep Extension?

The lying dumbbell tricep extension is a resistance training exercise where you lay on a bench and lower dumbbells toward your head. Then you extend your arms and contract your triceps to push the weight back up.

Another name for the lying dumbbell tricep extension is skull crushers. As you probably guessed, this nickname comes from the fact that you’re lowering heavy weights close to your head.

However, the lying dumbbell tricep extension is a perfectly safe exercise when executed properly.

Lying Dumbbell Tricep Extension Muscles Worked

As the name suggests, lying dumbbell tricep extensions mainly work the triceps. That’s because this exercise involves extending the forearm about the elbow joint, which is a primary function of the tricep muscle.

But it’s also important to know that the tricep has three different muscle heads, hence the prefix “tri”. The three segments are called the lateral, medial, and long heads of the tricep.

Lying dumbbell tricep extensions work all three tricep heads quite well. However, the body mechanics of this exercise are best suited for working the lateral and medial heads.

Lying Dumbbell Tricep Extension Benefits

Dumbbell lying tricep extensions have some advantages over the traditional barbell or EZ bar variations.

First, the dumbbell lying tricep extension is a good option for home gyms because you don’t need specialized barbells, plates, or clips. All you need is a pair of dumbbells.

Second, holding two separate dumbbells forces each arm to work separately. So you build more balance, coordination, and stability.

Finally, dumbbells give you more freedom in the range of motion because there is no barbell to smack you in the forehead! That means you can adjust the movement to your individual needs and preferences.

Benefits of Dumbbell Lying Tricep Extension:

• Minimal equipment needed
• Better for coordination/stability
• More flexible movement path

Of course, there are disadvantages too. For example, you may not have the right size dumbbells at your disposal. And barbells make it easier to overload the triceps with heavy loads.

How to Do a Lying Dumbbell Tricep Extension

Start by grabbing a dumbbell in each hand. Then sit on a bench and place the dumbbells on your thighs.

At this point, I recommend sliding your hands down, so the edge of your palm rests against the inside head of the dumbbell. This way, the dumbbell won’t slide down as you perform the exercise.

Next, lean back on the bench with your upper body lying horizontal. It’s also a good idea to scootch up, so your head is at the top of the bench. Now extend the dumbbells to arm’s length straight over your chest.

Before you begin, tilt your extended arms a few degrees toward your shoulders. This slight adjustment helps keep tension on your triceps through the whole range of motion.

Next, lower the weight by bending your elbows without moving your upper arms. Once the dumbbells reach the top of your head, extend your forearms to the starting position.

Step-by-Step Directions:

• Grab a dumbbell in each hand
• Sit down on the bench with dumbbells on your thighs
• Position your hands against the inside end of the dumbbells
• Lay back on the bench
• Press the dumbbells to arm’s length in front of the chest
• Tilt extended arms a few degrees toward shoulders
• Lower the weight by bending at the elbows
• Extend arms back to the starting position

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Form

Lying Dumbbell Tricep Extension Variations

There are also several different ways to do lying tricep extensions with dumbbells, barbells, or cables.

Incline Lying Dumbbell Tricep Extension

Incline dumbbell skull crushers are performed with an upward angle on the bench. The slope creates more tension on the triceps at the bottom of the movement.

You can also do this on a decline angle, reducing the stretch at the bottom. Some people report this is easier on their elbows.

Lying Dumbbell Tricep Extension Alternatives

Lying dumbbell tricep extensions (aka skull crushers) are an awesome exercise for overall tricep development. However, there are times when you may need to rotate this exercise out of your arm workouts.

For me, this happens periodically when I have elbow pain from overuse or other injuries. Or you might just feel like trying another tricep exercise for targeting the medial and lateral heads.

Whatever the reason, I’ve compiled a complete list of the 13 best skull crusher alternative exercises. Click the link to check them out!

More Tricep Exercises

Now that you know how to properly do dumbbell lying tricep extensions, you can safely add them to your workouts and start building bigger triceps. But for maximum results, make sure you’re targeting all three tricep heads.

Check out these other super informative articles for building bigger triceps and arms.

Top Lateral Head Tricep Exercises

13 Medial Head Tricep Exercises

Best Long Head Tricep Exercises

21 Cable Arm Exercises

How to Do Weighted Dips for Triceps

3 Cable Tricep Pressdown Mistakes & How to Fix Them

With this information, you’re well on your way to building thicker triceps and stronger arms. Now feel free to browse some of my other fitness and nutrition-related articles.