Skull Crusher 1RM Calculator

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Skull Crusher Strength Standards (kg)

Body Weight Beginner Novice Intermediate Advanced Elite
120 kg 0 10 25 45 70
130 kg 0 10 25 45 75
140 kg 0 15 30 50 80
150 kg 0 15 35 55 85
160 kg 0 20 35 55 90
170 kg 0 20 40 60 95
180 kg 0 25 45 65 100
190 kg 0 25 45 70 105
200 kg 0 25 50 70 110
210 kg 0 30 50 75 115
220 kg 0 30 55 80 120

How to Perform the Skull Crusher

Lie on a flat bench holding an EZ-bar or straight barbell with a narrow grip, arms extended straight above your chest. Keeping your upper arms stationary and perpendicular to the floor, bend at the elbows to lower the bar toward your forehead or just behind the top of your head. When your forearms are just past parallel to the floor, reverse the motion and extend your arms back to the starting position by contracting the triceps.

Muscle Activation

The skull crusher is one of the most effective isolation exercises for the triceps because it trains the long head through a stretched position, which is critical for complete tricep development. All three heads of the triceps, the long head, lateral head, and medial head, contribute to elbow extension during this movement. Lowering the bar behind the head rather than to the forehead increases the stretch on the long head.

Common Mistakes

  • Flaring the elbows out wide, which reduces tricep isolation and can stress the elbows.
  • Moving the upper arms during the exercise, which turns it into a close-grip press rather than an isolation movement.
  • Lowering the bar directly to the forehead rather than slightly behind the head, which limits the stretch on the long head.
  • Using too much weight and compensating with momentum or shoulder movement.

Variations

Dumbbell skull crushers allow independent arm movement. Incline skull crushers increase the stretch on the long head. Cable skull crushers provide constant tension. Overhead tricep extensions, while not technically skull crushers, train the triceps in a similar stretched position and are an excellent alternative.

Programming Tips

Perform 3-4 sets of 10-15 reps, 1-2 times per week. Start with lighter weights to protect the elbow joints and gradually increase loading. Skull crushers pair well with bicep exercises in superset fashion. If you experience elbow pain, try using an EZ-bar or dumbbells for a more joint-friendly grip angle.

Frequently Asked Questions

Skull crushers can cause elbow discomfort if performed with excessive weight or poor form. Use a controlled tempo, avoid locking out aggressively, and use an EZ-bar to reduce wrist and elbow stress.
Lowering the bar slightly behind the top of your head provides a greater stretch on the long head of the triceps, which is generally preferred for hypertrophy. The forehead version is also acceptable.
An EZ-bar is the most popular choice as it reduces wrist and elbow strain. A straight barbell also works but may cause more joint discomfort for some lifters. Dumbbells are another option.
Use a weight that allows 10-15 controlled reps. Skull crushers are not a strength exercise; focus on the stretch and contraction rather than maximizing weight.

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