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  5. Chest
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  7. Kettlebell Lying Triceps Extension Skull Crusher

Exercise guide

Kettlebell Lying Triceps Extension Skull Crusher

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

This isolation exercise targets all three heads of the triceps, using the kettlebell's unique center of gravity to provide constant tension and a deep stretch. It is highly effective for building lockout strength and improving elbow stability.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Kettlebell Lying Triceps Extension Skull Crusher demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Triceps

Secondary

  • Abs
  • Obliques

Equipment

  • Kettlebell

Setup

  1. Lie flat on a bench with your feet planted firmly on the floor for stability.
  2. Hold a kettlebell in each hand using a neutral grip (palms facing each other) with arms extended directly over your shoulders.
  3. Position the kettlebells so the bell portion is resting against the back of your forearms.
  4. Retract your shoulder blades into the bench to create a stable base.

How to do it

  1. Inhale as you slowly bend your elbows to lower the kettlebells toward the sides of your forehead or ears.
  2. Keep your upper arms stationary and perpendicular to the floor throughout the descent.
  3. Exhale as you contract your triceps to extend your arms back to the starting position.
  4. Maintain a controlled tempo, focusing on a 2-second eccentric (lowering) phase and a 1-second squeeze at the top.

Form checklist

  • Keep your elbows tucked in and pointing forward; do not let them flare out.
  • Ensure the movement occurs exclusively at the elbow joint; keep the shoulders still.
  • Maintain a neutral wrist position to avoid strain from the kettlebell's weight.
  • Keep your lower back pressed against the bench to prevent arching.

Pro tips

  • Angle your upper arms slightly back toward your head (about 10-15 degrees) to keep the triceps under tension even at the top of the rep.
  • Focus on the 'stretch' at the bottom of the movement to maximize recruitment of the long head of the triceps.

Make it harder

  • Perform the movement on a slight decline bench to increase the range of motion and stretch.
  • Add a 3-second pause at the bottom of each rep to eliminate momentum and increase time under tension.

Frequently asked

What muscles does the kettlebell lying triceps extension skull crusher work?
The kettlebell lying triceps extension skull crusher primarily targets the triceps, and also works the abs and obliques as secondary muscles.
What equipment do you need for the kettlebell lying triceps extension skull crusher?
The kettlebell lying triceps extension skull crusher uses kettlebell.
Is the kettlebell lying triceps extension skull crusher good for beginners?
The kettlebell lying triceps extension skull crusher 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 Incline 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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