Skull crusher: how to do it
Main muscles: Triceps long head, Triceps medial head. Helpers: Triceps lateral head. Below: step-by-step form, common mistakes, a muscle map, reps and rest, and what to swap it for.
Equipment
Barbell
Reps
8–12
Rest
105 s
Muscle group
Arms
How to do it
- Lying or seated: the upper arms stay still and point straight up.
- Bend the arms and lower the bar to the forehead or behind the head; only the elbows work.
- Extend fully, but without a hard snap.
Common mistakes
Moving the upper arm, letting the elbows flare out.
Muscles worked
primary·secondary
- Primary
- Triceps long head, Triceps medial head
- Secondary
- Triceps lateral head
A secondary muscle gets roughly half the stimulus of a set — that is also how the log’s stats count it.
Programs that use it
- Upper/lower, 4 days3 × 8–12
- Lower body focus, 3 days3 × 8–12
Alternatives: similar exercises
Dips
Bodyweight · Lower chest, Triceps lateral head, Triceps medial head
Cable pushdown
Cable · Triceps lateral head, Triceps medial head
Overhead dumbbell extension
Dumbbells · Triceps long head, Triceps medial head
Triceps kickback
Dumbbells · Triceps long head, Triceps lateral head
Bench dips
Bodyweight · Triceps lateral head, Triceps medial head
Close-grip push-ups
Bodyweight · Triceps lateral head, Triceps medial head
Log your sets — the app suggests the next weight
GymAssist tracks the load on each of 40 muscles, paints it on a body map and uses double progression to tell you when to add weight.
Free forever for the first 500