Dumbbell Lying Triceps Extension
What Is the Dumbbell Lying Triceps Extension?
Dumbbell Lying Triceps Extension is an isolation exercise that primarily targets the triceps, with the long, lateral and medial heads working together to straighten the elbow. It is an intermediate-level movement typically performed on a flat bench using two dumbbells simultaneously.
The exercise builds triceps size and elbow-extension strength, the joint action that finishes a bench or overhead press. Lifters usually program it as an accessory after their main pressing work, such as the Barbell Bench Press (Close Grip), rather than as the first lift of a session.
Held with a neutral grip, the two dumbbells pass on either side of the head, so the elbows can bend further than in a Barbell Skull Crusher, where the bar stops at the forehead. The independent movement of each arm also helps address muscle imbalances, promoting symmetry and stability. Lying flat on a bench gives you more control, while the dumbbells let your wrists move naturally, reducing joint strain.
The long head is the only part of the triceps that crosses the shoulder, so the angle of the upper arm changes how much it is stretched. Here the upper arms stay close to vertical, which lengthens the long head more than a pushdown with the arms at your sides but less than a Dumbbell Overhead Triceps Extension, where the arms are raised beside the head.
The lift suits anyone who already trains the triceps and wants a free-weight extension that is easy to set up on a bench. If controlling dumbbells beside your head feels unsteady, build up with a Cable Triceps Pushdown (Rope) first to learn to straighten the elbow while the upper arm stays still.
Muscles Worked
- Triceps Brachii (Long Head)
- Primary
- Deltoid
- Low
- Teres Major
- Minimal
Instructions
- Sit on the end of a flat bench with a dumbbell in each hand resting on your thighs, then lie back and bring the dumbbells to your chest.
- Keep your head, upper back and hips on the bench and plant your feet flat on the floor.
- Press the dumbbells straight up above your shoulders with a neutral grip, palms facing each other, and the dumbbells a few inches apart.
- Keeping your elbows pointing up and your upper arms almost still, bend your elbows to lower the dumbbells slowly to either side of your head.
- Stop when the dumbbells reach about ear level and you feel a stretch in the back of your upper arms.
- Keep your elbows about shoulder-width apart instead of letting them flare out.
- Straighten your elbows to press the dumbbells back up until your arms are straight above your shoulders.
- Repeat for the desired number of reps, then lower the dumbbells to your chest before you sit up.
Common Mistakes
Letting elbows flare out
Flaring elbows reduces triceps isolation and increases shoulder involvement.
Moving the upper arms
Swinging the upper arms back on the way down and forward on the way up turns the lift into a partial pullover and takes work off the triceps.
Using excessive weight
Heavy dumbbells can compromise form and increase risk of elbow strain.
Lowering dumbbells too far
Overstretching can place stress on the shoulder joint and connective tissue.
Rushing the movement
Performing the exercise too quickly reduces muscle control and increases injury risk.
Injuries
Dumbbell Lying Triceps Extension is a medium risk exercise when performed with proper technique.
The most common issues are elbow discomfort or strain, especially if too much weight is used or the descent is uncontrolled. The load peaks at the bottom, where the elbow is most bent and the triceps tendon pulls hardest on the point of the elbow. Shoulder tension may also arise if the dumbbells drift too far backward. Because the dumbbells travel close to your head, a rep you cannot finish is a real hazard when you train alone.
To prevent injuries, start with lighter weights to learn the motion. Keep your elbows steady and avoid rapid or jerky movements. Warming up the elbows with light sets or mobility drills is also beneficial. Keep the dumbbells a few inches apart so they clear your head, and finish each set by bringing them down to your chest before you sit up rather than dropping them beside your head.
If your elbows are sensitive, the Cable Triceps Pushdown (Rope) trains the same muscle with the weight nowhere near your head. Progress by adding load in small steps, or move to the EZ Bar Lying Triceps Extension once the dumbbell version feels solid. Stop if you feel sharp or pinching pain at the back of the elbow or the front of the shoulder, or pain that lingers after the set, and see a clinician if it comes with swelling or weakness.
Frequently Asked Questions
- Q: Should I lower the dumbbells to the sides of my head or behind it?
Lowering them beside your head at about ear level, with the upper arms close to vertical, is the standard version. Letting the upper arms tilt further back so the dumbbells travel behind your head adds shoulder flexion and stretches the long head more, but it also asks more of the shoulder, so go there only if it stays comfortable and your elbows stay still.
- Q: How is this different from an overhead triceps extension?
Both bend and straighten the elbow, but here the upper arms point at the ceiling, while a Dumbbell Overhead Triceps Extension raises them beside your head. Because the long head of the triceps crosses the shoulder, the overhead version holds it at a longer length, while the lying version is easier to set up and control on a supported bench.
- Q: Is the dumbbell version easier on the elbows than a barbell skull crusher?
Many lifters find it is, because each hand can settle into a neutral grip instead of being locked to a bar. If a straight bar bothers your elbows, the angled grip of the EZ Bar Lying Triceps Extension sits between the two.
- Q: Can I do this exercise on the floor instead of a bench?
It’s possible but limits range of motion, making a bench the better choice for full effectiveness.
- Q: How many sets and reps should I do for triceps growth?
3 to 4 sets of 8 to 12 reps is effective for hypertrophy in most training programs.