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Barbell Lying Extension animation

How to do the Barbell Lying Extension

TricepsBarbellIntermediate

The barbell lying extension, often called the skull crusher, is one of the most direct and effective tools for building thick, powerful triceps mass. Master the mechanics and you will feel every rep exactly where it counts.

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Muscles worked

Primary
Triceps
Secondary
Front deltsChest

Step-by-step

  1. Lie flat on a bench and grip the barbell with an overhand grip slightly narrower than shoulder-width, arms locked out directly over your chest.
  2. Keeping your upper arms stationary and vertical, hinge only at the elbows to lower the bar in a controlled arc toward your forehead or just behind it.
  3. Pause briefly at the bottom without letting your elbows flare outward, then drive the bar back up by forcefully extending through the triceps.
  4. Lock out completely at the top of each rep to maximize triceps contraction before beginning the next controlled descent.

Common mistakes

  • Letting the elbows flare wide as the weight gets heavy — consciously keep them tracking straight forward throughout the entire movement to protect the joint and keep tension on the triceps.
  • Using the shoulders to push the weight up instead of isolating the elbow extension — if your upper arms are drifting toward your face on the way up, reduce the load and reset your position.
  • Rushing the eccentric and dropping the bar fast — slow the lowering phase to at least two seconds to build real strength and reduce injury risk at the elbow.

Pro tip — Angle your upper arms very slightly back toward your head rather than perfectly perpendicular to the floor — this keeps constant tension on the long head of the triceps throughout the full range of motion instead of giving it a slack point at the top.

Sets & reps by goal

Build muscle3–4 sets × 10–15 reps
Get stronger3–4 sets × 6–8 reps
Lose fat / tone3 sets × 12–20 reps

Rest: 60–90 sec between sets.

More Triceps exercises

Barbell Close Grip Bench PressBarbell Close Grip Bench PressBarbell Decline Close Grip To Skull PressBarbell Decline Close Grip To Skull PressBarbell Incline Reverse Grip PressBarbell Incline Reverse Grip PressBarbell Lying Close Grip PressBarbell Lying Close Grip PressBarbell Lying Close Grip Triceps ExtensionBarbell Lying Close Grip Triceps ExtensionBarbell Seated Overhead Triceps ExtensionBarbell Seated Overhead Triceps Extension
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