Are you looking for a simple and effective dumbbell exercise to inflate the back of your upper arms?
If so, the dumbbell skull crusher is a great option. The exercise is relatively easy to learn, develops the triceps, and provides decent overload, even for advanced trainees.
Read on to learn more about the exercise, including how to do it, what useful variations you can pick from, and how to combine it with other movements.
Table of Contents
Main Takeaways
What They Are
Despite its unsettling name, the dumbbell skull crusher is a safe and effective exercise. The skull crusher is an isolation exercise that works around a single joint (the elbow) and emphasizes one muscle group (the tricep).
Other muscles with a role in skull crushers include:
- Midsection (abs, obliques, etc.) that provides stability
- Shoulders (deltoids) for stability
The traditional way to perform the exercise is by using a pair of dumbbells on a flat gym bench.
Here are step-by-step instructions:
- Grab a pair of light dumbbells and lie on a flat gym bench.
- Extend your arms and position the dumbbells above your shoulders with your palms facing as you hold the dumbbells.
- Retract your shoulder blades, take a deep breath, and engage your abs.
- Slowly bend your elbows to bring the dumbbells to the sides of your head.
NOTE: Try to imagine your elbows are fixed on a hinge. - Pause for a moment and straighten your arms back to the start position as you exhale.
Skull Crusher Video
Variations
1. Bench
The classic way to perform skull crushers is to lie on a flat gym bench. You can also lie on a slight incline of roughly 30 degrees.
2. Floor
This variation is identical to bench skull crushers. The only difference is that you’re lying on the floor.
3. Single-Arm
Single-arm skull crushers are a variation where you train one arm at a time. The variation makes it easier to focus on one muscle at a time, and it works great if you only have one dumbbell. (1)
Skull Crushers With EZ Bars
Combination Exercises
Dumbbell skull crushers can work great with a variety of other chest exercises, including:
- Bench dips
- Cable tricep extensions
- Seated dumbbell extensions
- Tricep kickbacks
- Close-grip bench press
- Diamond push-up
For example, if you’re at a gym, you can do the following:
- Close-grip bench press
- Cable tricep extensions
- Dumbbell skull crushers
If you’re at home, you can do the following:
- Bench/chair dips
- Diamond push-ups
- Dumbbell skull crushers
Safety And Final Thoughts
Like any other exercise, start with lighter weights and progress from there. It takes time to master proper form, and using heavy dumbbells can cause you to ingrain poor motor patterns. (2)
Additionally, maintain a solid grip on the dumbbells at all times. Doing so is vital for keeping yourself safe. The weights will be directly overhead multiple times per set, and you wouldn’t want to drop one on your face.
Finally, we have a technique tip that promotes safety and better muscle activation. Specifically, you should strive to extend the dumbbells away from your head. Do so by bringing your elbows to the sides of your head at the start of the set. As you extend your arms, the dumbbells won’t be directly over your face.
In addition to keeping the weights away from your face, this technique tweak can make it easier to stretch the long tricep head, leading to better activation and potentially more growth.
Improve flexibility and reduce muscle tension with this tricep stretch—a great addition to your tricep workouts for better performance and recovery.
Build strong, defined arms with this triceps workout at home without equipment, perfect for targeting your triceps using just bodyweight exercises. For a complete upper body routine, this arm workout with dumbbells at home delivers targeted moves to build both strength and size with minimal equipment.
Chest stretches help improve flexibility, reduce muscle tightness, and enhance overall upper-body mobility, making them a great addition to any workout or recovery routine.
Click here to learn how to target your lower chest at home. Click here to learn more about chest and tricep dumbbell workouts. Click for more dumbbell workouts.
Philip Stefanov
Philip is a fitness writer, blogger, certified personal trainer, and the founder of ThinkingLifter.com. He has spent the last nine years writing fitness content and training men and women in the gym, as well as online. His passion is fitness and exercise, and helping others improve their fitness and wellness.
References
- Theunissen, S. (Last Updated: 2024, August 11). Single-Arm Skull Crusher: Target your triceps & more! Fitness Volt. https://fitnessvolt.com/single-arm-skull-crusher/
- Ultimate Performance (2022, September 20). Building muscle and strength: Is lifting heavy weights always better? Ultimate Performance Blog. https://blog.ultimateperformance.com/building-muscle-and-strength-is-lifting-heavy-weights-always-better/