How to Do Dumbbell One-Arm Triceps Extension

Dumbbell One-Arm Triceps Extension — start position demonstration photo
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Dumbbell One-Arm Triceps Extension — end position demonstration photo
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Start and end of one clean rep of Dumbbell One-Arm Triceps Extension.

Quick facts

Primary muscleTriceps
Secondary muscles—
EquipmentDumbbell
CategoryStrength

How to perform Dumbbell One-Arm Triceps Extension

  1. Grab a dumbbell and either sit on a military press bench or a utility bench that has a back support on it as you place the dumbbells upright on top of your thighs or stand up straight.
  2. Clean the dumbbell up to bring it to shoulder height and then extend the arm over your head so that the whole arm is perpendicular to the floor and next to your head. The dumbbell should be on top of you. The other hand can be kept fully extended to the side, by the waist, supporting the upper arm that has the dumbbell or grabbing a fixed surface.
  3. Rotate the wrist so that the palm of your hand is facing forward and the pinkie is facing the ceiling. This will be your starting position.
  4. Slowly lower the dumbbell behind your head as you hold the upper arm stationary. Inhale as you perform this movement and pause when your triceps are fully stretched.
  5. Return to the starting position by flexing your triceps as you breathe out. Tip: It is imperative that only the forearm moves. The upper arm should remain at all times stationary next to your head.
  6. Repeat for the recommended amount of repetitions and switch arms.

Muscles worked

  • Triceps (primary): straightens the elbow to lock out every press and pushdown.

Sets & reps by goal

GoalSets × repsLoadRest
Strength3–5 × 3–5Heavy (~85%+)2–3 min
Hypertrophy3–4 × 8–12Moderate (~65–75%)60–90 s
Endurance2–3 × 15–20Lighter (~50–60%)30–45 s

Pick the row that matches your goal. If you're newer, anchor in the hypertrophy range while you groove the form.

Form tips

  • Fix the elbows in place and let only the forearms move, keeping the load on the triceps.
  • Each side works on its own, so match the depth and speed of both arms and don't let the stronger side take over.
  • Treat every rep the same — a repeatable setup and bar path is what lets you add weight safely over time.
  • Control the lowering phase — a 2–3 second descent builds more than dropping the weight.

Common mistakes

  • Letting the elbows flare and drift forward so the shoulders quietly take over.
  • Letting the dumbbells drift apart or clang together at the top instead of controlling the path.
  • Chasing weight jumps before the current load feels solid on every rep.

Frequently asked questions

What muscles does Dumbbell One-Arm Triceps Extension work?

Dumbbell One-Arm Triceps Extension is a focused movement that primarily works the triceps.

What equipment do I need for Dumbbell One-Arm Triceps Extension?

Dumbbell One-Arm Triceps Extension needs a pair of dumbbells.

How many sets and reps should I do for Dumbbell One-Arm Triceps Extension?

It depends on your goal: about 3–5 sets of 3–5 heavy reps for strength, 3–4 sets of 8–12 for muscle growth, or 2–3 sets of 15–20 for endurance. Pick the row that matches your goal. If you're newer, anchor in the hypertrophy range while you groove the form.

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