Arms · Elbow extension

Seated Dumbbell Triceps Extension

The seated dumbbell triceps extension is an overhead movement where you sit with back support, hold one dumbbell with both hands above your head and lower it behind your head by bending your elbows. It stretches the long head of the triceps under load and the seat removes balance and lower-back strain.

Also known as: Seated overhead dumbbell extension, Seated French press, Two-hand seated triceps extension

Muscle group: Arms
Movement pattern: Elbow extension
Type: Isolation
Equipment: Dumbbell, Bench with back support
Difficulty: Beginner

What muscles does the seated dumbbell triceps extension work?

Primary movers

Triceps brachii (long head)

Assisting muscles

Triceps brachii (lateral and medial heads)
Anterior deltoid
Forearm flexors

Holding the dumbbell overhead stretches the long head of the triceps at the bottom of each rep, which is a strong stimulus for growth.

The seat back supports your spine, so you do not arch your lower back as you press. That is a common problem with the standing version.

Holding one dumbbell with two hands lets you use a heavier load than a single-arm version and keeps both arms moving symmetrically.

The elbows should stay pointing forward and close to your head. Letting them flare takes tension away from the triceps and strains the shoulders.

How to do the seated dumbbell triceps extension

Setup

1
Sit on a bench with back support and your feet flat.
2
Hold one dumbbell by the inside of the top plate with both hands.
3
Raise it overhead with your arms extended.
4
Keep your elbows close to your head.

Execution

1
Lower the dumbbell behind your head by bending your elbows.
2
Lower until you feel a deep stretch.
3
Straighten your elbows to press the dumbbell back up.
4
Squeeze your triceps at the top.
5
Keep your upper arms still.
6
Keep your back against the pad.

Common seated dumbbell triceps extension mistakes

Flaring the elbows

Wide elbows reduce triceps work.

The fix: Keep your elbows pointing forward.

Arching the back

Leaning back to push the weight up loads the spine.

The fix: Keep your back against the seat and brace your abs.

Too heavy

Heavy weights are hard to control behind the head.

The fix: Choose a weight you can control for 10 to 12 reps.

Short range

Not lowering enough misses the stretch.

The fix: Lower until your elbows are fully bent.

How many sets and reps?

Goal	Sets	Reps	Load	Rest
Hypertrophy	3	10–12	Moderate, 1–2 RIR	60–90 s
Stretch focus	3	12–15	Light to moderate	60 s
Beginner	2	10	Light	60 s

A simple long-head exercise that needs only one dumbbell. Use a back-supported seat and a slow lowering phase. Add weight when you can complete the top of the rep range.

Running the seated dumbbell triceps extension in your next block? Hercules logs every set, shows last session's numbers before you lift, and suggests when to add weight.

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