Single-Arm Overhead Dumbbell Extension

What is the Single-Arm Overhead Dumbbell Extension?

The single-arm overhead dumbbell extension isolates one triceps with the arm raised overhead, lowering the dumbbell behind the head and extending back up. Working one arm at a time deepens the long-head stretch, lets the wrist find a comfortable angle, and evens out side-to-side differences a two-handed extension can mask.

Muscles worked

Primary: Triceps

The triceps extends the elbow to press the dumbbell overhead; with the single arm raised, the long head is fully stretched at the bottom and worked through its longest range.

How to perform the Single-Arm Overhead Dumbbell Extension

1. Hold a single dumbbell in one hand and press it overhead until the arm is fully extended, palm facing forward or inward.
2. Working one arm overhead maximizes the long-head stretch and reveals side-to-side triceps differences a two-hand version hides.
3. Keep the working elbow pointing up close to the head, using the free hand to brace the working upper arm if needed.
4. Lower the dumbbell behind the head by bending the elbow, feeling the long head stretch deeply.
5. Keep the upper arm vertical and still so the elbow does not drift forward or out.
6. Extend the elbow to press the dumbbell back overhead, stopping just short of a hard lockout.

Suggested working range: 10–15 reps. Default progression: double progression.

Mechanics

A single-joint isolation performed one arm at a time: elbow extension with the upper arm held vertical, overhead. The overhead position lengthens the long head (which crosses the shoulder), and working one arm lets it travel into a deeper, cleaner stretch than a shared two-handed dumbbell.

Form cues

• •Raise one dumbbell overhead with the upper arm vertical and close to your head.
• •Lower behind the head to a deep stretch without flaring the elbow wide.
• •Extend fully to lock out overhead and squeeze the triceps at the top.
• •Keep the ribs down and core braced so you don’t arch the lower back.

Common mistakes

• •Flaring the working elbow out to the side, which loses the long-head stretch.
• •Letting the upper arm drift forward instead of keeping it vertical beside the head.
• •Snapping into a hard overhead lockout that stresses the elbow tendon.
• •Cutting the range short and never lowering the dumbbell fully behind the head.

Variations & alternatives

• •Two-handed overhead dumbbell extension, both hands on one dumbbell.
• •Overhead cable extension, constant tension on the stretched triceps.
• •Single-arm cable pushdown, the same arm from the shortened position.
• •Skull crusher, a lying long-head loader.

Tricep Pushdown

Triceps · Cable

Overhead Tricep Extension

Triceps · Dumbbell

Skull Crusher

Triceps · Barbell

Tricep Dip

Triceps · Bodyweight

Close-Grip Bench Press

Triceps · Barbell

Programming: sets, reps & when to use it

Program the single-arm overhead extension in the library’s 10–15 rep range as a stretch-focused triceps accessory, one arm at a time, letting the weaker side set the load. Control the lowering into the stretch and keep the elbow from flaring. Pair it with a pushdown to train both ends of the range; run it after pressing.

Frequently asked questions