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  7. Dumbbell Seated Triceps Extension

Exercise guide

Dumbbell Seated Triceps Extension

  • Intermediate
  • Isolation
  • Rep-based
  • Upper arms

This isolation exercise targets all three heads of the triceps, with a specific emphasis on the long head by placing it in a fully stretched overhead position. It is highly effective for building arm thickness and improving elbow extension strength.

Reviewed by the Crucible team · Updated June 2026

Watch the Dumbbell Seated Triceps Extension demonstrationGuided video and your full workout live in the Crucible app.

Muscles worked

Primary

  • Triceps

Secondary

  • Deltoids
  • Forearms

Equipment

  • Dumbbell

Setup

  1. Sit on a flat bench with your feet planted firmly on the floor for stability.
  2. Hold a single dumbbell with both hands, forming a diamond shape with your palms against the underside of the top weight plate.
  3. Lift the dumbbell directly overhead until your arms are fully extended and your upper arms are tucked close to your ears.

How to do it

  1. Inhale and slowly lower the dumbbell behind your head by bending only at the elbows, keeping your upper arms vertical and stationary.
  2. Lower the weight until your forearms are at least parallel to the floor or you feel a deep stretch in your triceps.
  3. Exhale and press the dumbbell back to the starting position by extending your elbows, following a controlled 2-second up, 3-second down tempo.
  4. Squeeze your triceps at the top of the movement before beginning the next repetition.

Form checklist

  • Keep your elbows tucked in toward your head; do not let them flare out to the sides.
  • Maintain a neutral spine and avoid arching your lower back as you lower the weight.
  • Ensure only your forearms move; your upper arms should remain perpendicular to the floor.
  • Keep your core engaged to prevent the torso from swaying.

Pro tips

  • Focus on the 'stretch' at the bottom of the movement to maximize recruitment of the triceps' long head.
  • Think about pressing the weight toward the ceiling rather than just 'up' to ensure full elbow extension.

Make it harder

  • Perform the movement unilaterally (one arm at a time) to challenge your core stability and fix muscle imbalances.
  • Add a 2-second pause at the bottom of each rep to increase time under tension in the stretched position.

Frequently asked

What muscles does the dumbbell seated triceps extension work?
The dumbbell seated triceps extension primarily targets the triceps, and also works the deltoids and forearms as secondary muscles.
What equipment do you need for the dumbbell seated triceps extension?
The dumbbell seated triceps extension uses dumbbell.
Is the dumbbell seated triceps extension good for beginners?
The dumbbell seated 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 Assisted DipIntermediate · triceps
  • Band Bent Over One Arm Neutral Grip KickbackBeginner · triceps

Train this with a plan, not guesswork

Crucible builds the dumbbell seated triceps extension into a precise program around your body, equipment, location, and time.

Download on the App Store