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  5. Shoulders
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  7. Dumbbell Seated Single Arm Overhead Triceps Extension

Exercise guide

Dumbbell Seated Single Arm Overhead Triceps Extension

  • Intermediate
  • Isolation
  • Rep-based
  • Shoulders
  • Upper arms

This isolation exercise specifically targets the long head of the triceps by placing the muscle in a fully stretched position. Performing it unilaterally allows for a greater range of motion and helps identify and correct strength imbalances between arms.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Dumbbell Seated Single Arm Overhead Triceps Extension demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Triceps

Secondary

  • Abs
  • Deltoids

Equipment

  • Dumbbell

Setup

  1. Sit upright on a flat bench with your feet planted firmly on the floor for stability.
  2. Hold a dumbbell in one hand and extend your arm straight up toward the ceiling.
  3. Place your non-working hand on your opposite shoulder or use it to lightly support the working arm's elbow to keep it stationary.
  4. Engage your core and maintain a neutral spine to prevent your lower back from arching.

How to do it

  1. Inhale as you slowly lower the dumbbell behind your head by bending only at the elbow, keeping your upper arm vertical and close to your ear.
  2. Lower the weight until your forearm is at least parallel to the floor or you feel a deep stretch in the triceps.
  3. Exhale as you contract your triceps to extend the arm back to the starting position, following a controlled 2-1-2 tempo (2 seconds down, 1 second pause, 2 seconds up).
  4. Complete all repetitions on one side before switching to the other arm.

Form checklist

  • Keep the upper arm stationary and vertical throughout the entire set.
  • Avoid flaring the elbow out to the side; keep it tucked in toward your head.
  • Ensure the movement occurs exclusively at the elbow joint, not the shoulder.
  • Maintain an upright torso without leaning or arching the back to compensate for the weight.

Pro tips

  • Focus on the 'deep stretch' at the bottom of the movement to maximize recruitment of the triceps long head.
  • Squeeze the triceps hard at the top of the rep, but avoid a hard lockout to keep constant tension on the muscle.

Make it harder

  • Add a 2-second pause at the bottom (the stretch position) to eliminate momentum and increase time under tension.
  • Perform '1.5 reps' by lowering the weight fully, coming halfway up, lowering again, and then extending to the top.

Frequently asked

What muscles does the dumbbell seated single arm overhead triceps extension work?
The dumbbell seated single arm overhead triceps extension primarily targets the triceps, and also works the abs and deltoids as secondary muscles.
What equipment do you need for the dumbbell seated single arm overhead triceps extension?
The dumbbell seated single arm overhead triceps extension uses dumbbell.
Is the dumbbell seated single arm overhead triceps extension good for beginners?
The dumbbell seated single arm overhead triceps extension is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Arm Double CrossoverIntermediate · biceps, deltoids, and triceps
  • Aztec Push UpIntermediate · pectorals, serratus anterior, and triceps
  • Band Bent Over One Arm Neutral Grip KickbackBeginner · triceps
  • Band High Pulley Overhead Triceps ExtensionIntermediate · triceps

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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