Tricep pushdown vs skull crusher vs overhead extension

Tricep pushdown, skull crusher and overhead extension all work the triceps and — in the Zyra Workouts catalog — nothing else: three isolation rows with an empty secondary list. The fourth triceps-primary lift, the close-grip bench press, is the compound of the group and brings chest and shoulders along. This guide compares the three isolations — the tricep pushdown, the skull crusher and the overhead tricep extension — on what actually differs, then places the close-grip bench beside them.

Muscles worked

Every one of these is elbow extension: the triceps straighten the arm against a load. Mechanically the variable is where the upper arm points, because the long head of the triceps also crosses the shoulder and is longer when the arm is overhead than when it hangs by the side. Pushdown: upper arm down, long head short. Skull crusher: upper arm roughly vertical or tilted back, long head longer. Overhead extension: upper arm straight up, long head longest. That is a description of anatomy and position — the catalog credits one triceps group on all three, and this page cites no EMG study to rank them.

Three isolations and the compound, side by side

Setup and execution

• Tricep pushdown: high pulley, straight bar or rope. Elbows pinned to the sides, forearms rising to about horizontal at the start; push down until the arms are straight, return under control without letting the elbows drift forward.
• Skull crusher: lie on a bench with a barbell or EZ bar held over the face at arm's length, upper arms tilted slightly back toward the head. Bend only at the elbows to lower the bar to just above the forehead (or behind it), then extend.
• Overhead tricep extension: seated or standing, one dumbbell held in both hands overhead. Lower it behind the head by bending the elbows, keeping the upper arms pointing up, then extend.
• Close-grip bench press: the bench press with the hands about shoulder-width and the elbows tracking closer to the body; the bar travels a little further and touches a little lower.

Rep and RIR targets by goal

The three isolations use the isolation table; the close-grip bench uses the compound one.

Close-grip bench press (compound):

RIR is reps in reserve — how many more reps were left when the set stopped. @RIR 2 means the set ended two reps short of failure. The rep ceiling is the engine's "expected max": the midpoint of the range plus the RIR target, round((repMin + repMax) / 2) + rir. Beat the ceiling and the load steps up next time.

How progression steps on this exercise

Cable and dumbbell rows step 2 kg; the two barbell rows step 2 × 1.25 = 2.5 kg and carry the plate check. On the isolation hypertrophy target (10–15 @RIR 1, ceiling 14) and the compound one (6–10 @RIR 2, ceiling 10):

In plain terms: same rule everywhere; the step and the ceiling come from the row. The close-grip bench 1RM page is the one in this group where an estimated max is genuinely useful.

Alternatives

Only five rows in the catalog are triceps-primary (these four plus the tricep dip), so every list here is the remainder, ordered by the rule (+4 loadable, +2 same category, +1 same equipment, then name):

Swapping an isolation for the close-grip bench keeps the triceps set and adds 0.5 to chest and shoulders; swapping the other way removes that half-credit. The tricep dip is last on the isolation lists only because it is bodyweight in a gym that has plates — feasibility is scored, not difficulty.

The short version

Pushdown, skull crusher and overhead extension: triceps only, isolation targets, one triceps set each — differing in where the upper arm points, in the step (2 kg cable and dumbbell, 2.5 kg barbell) and in rest (60 / 90 / 60 s). The close-grip bench press is the compound cousin: triceps first, chest and shoulders at 0.5, compound targets, 150 s. Zyra Workouts is a training log, and this page is a guide to one movement in its catalog. Educational overview only — not medical advice.