Dumbbell Seated Single Arm Overhead Triceps Extension (left)
- Target muscle
- —
- Equipment
- Dumbbell
- Body part
- Upper Arms
- Type
- Strength
The dumbbell seated single arm overhead triceps extension (left) is an isolation exercise that targets the triceps of the left arm, with emphasis on the long head thanks to the overhead position. Performed seated with one dumbbell, it lets you train each arm independently to even out strength imbalances and build the size and lockout strength behind the upper arm.
How to do the Dumbbell Seated Single Arm Overhead Triceps Extension (left)
- 1Sit upright on a bench with your feet flat on the floor and your back tall. Hold a dumbbell in your left hand.
- 2Press the dumbbell overhead until your left arm is fully extended, with the weight directly above your shoulder.
- 3Keep your left upper arm vertical and close to your head, pointing your elbow toward the ceiling.
- 4Brace your core and, if it helps, support your left elbow with your right hand to keep the upper arm still.
- 5Lower the dumbbell behind your head by bending only at the left elbow, until you feel a stretch in the triceps.
- 6Pause briefly at the bottom without letting the weight drop or your upper arm drift forward.
- 7Press the dumbbell back up by extending your left elbow until the arm is fully straight, squeezing the triceps at the top.
- 8Complete your reps on the left arm, then lower the dumbbell under control and switch sides if programmed.
Form tips
- Keep your left upper arm vertical and stationary throughout the set so the work stays on the triceps, not the shoulder.
- Move only at the elbow — the dumbbell travels in an arc behind your head while the upper arm stays fixed.
- Use a full range of motion: get a deep stretch at the bottom and a hard lockout at the top for the most growth.
- Brace your core and avoid arching your lower back as the weight passes behind your head.
Common mistakes
- Letting the left elbow flare out and drift forward, which shifts the load onto the shoulder and shortens the triceps' range.
- Using too heavy a dumbbell and swinging the torso to heave it up, which removes tension from the triceps and risks a strain.
- Stopping short of full extension at the top, so you miss the lockout that trains the triceps hardest.
- Dropping the weight quickly behind your head instead of lowering it under control, straining the elbow joint.
Frequently asked questions
What muscles does the dumbbell seated single arm overhead triceps extension work?
It isolates the triceps of the working (left) arm. The overhead position places extra stretch and emphasis on the long head of the triceps, which runs along the back of the upper arm.
Why train one arm at a time instead of both?
Working the left arm on its own lets you correct side-to-side strength imbalances, keep strict form, and fully focus on the triceps without the stronger arm taking over.
How many sets and reps should I do?
For triceps size, 2–4 sets of 10–15 reps per arm with a controlled tempo works well. Use a weight that lets you reach full extension on every rep with strict form.
Is this exercise good for beginners?
Yes. Seated and single-arm, it is easy to control and you can brace the working elbow with your other hand. Start light to learn the path before adding weight.
