Overhead press: muscles worked (barbell, dumbbell, Arnold)

The overhead press works the shoulders first, with the triceps and the core as secondary muscles — and the Zyra Workouts catalog says the same thing for all three of its overhead rows: the barbell overhead press, the dumbbell overhead press and the Arnold press. This guide covers what is shared (muscles, targets, the step rule) and the three things that differ (equipment, rest, the Arnold rotation).

Muscles worked

Mechanically, pressing a load straight up is shoulder flexion and abduction (the deltoid lifts the upper arm overhead) finished by elbow extension (triceps). Standing, the trunk has to hold a load that is trying to fold it backward, which is why the catalog credits the core — and why a seated press changes the feel but not the row. The chest is not on the list: with the pressing line vertical rather than horizontal, the app does not count an overhead press toward chest volume at all. All of this is a description of the movement, not an EMG measurement.

Three rows compared

The Arnold press is the dumbbell press with a rotation: the palms start facing you and turn forward as the dumbbells rise, so the elbows travel from the front to the sides. Same muscles in the catalog, shorter default rest.

Setup and execution

1. Barbell: grip just outside the shoulders, bar resting on the front of the shoulders, elbows slightly ahead of the bar. Brace the trunk, press straight up, move the head back out of the path and then forward under the bar as it passes the forehead. Lock out with the bar over the middle of the foot.
2. Dumbbell: start with the dumbbells at shoulder height, press up and slightly in until the arms are straight, lower under control to the start.
3. Arnold: start palms in, elbows forward; rotate the palms out as you press; reverse on the way down.
4. Standing or seated is your choice — keep it constant so the progression engine compares like with like.
5. Log barbell loads as the bar total (bar included) and dumbbell loads per hand.

Rep and RIR targets by goal

All three rows are 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

The barbell row steps by 2 × 1.25 = 2.5 kg with the default plate set; both dumbbell rows step 2 kg per hand. On a strength target (3–5 @RIR 2, ceiling 6) the barbell rule plays out like this:

Note the middle row: hitting the ceiling exactly is a hold, not a progress. The rule is strictly "more than", so the load moves on 7 reps, not 6. In plain terms: the ceiling is the number to beat, not to reach. The barbell 1RM page estimates a single-rep max from any of these sets.

Alternatives

Ranked for the barbell overhead press (same primary muscle, +4 loadable, +2 same category, +1 same equipment, then name):

Only three shoulder-primary compounds exist in the catalog, so the list drops to isolation moves at rank 3. A swap to an isolation keeps the shoulder count but loses the 0.5 credited to triceps and core.

The short version

Shoulders primary, triceps and core secondary, no chest credit — for the barbell, dumbbell and Arnold press alike. Compound targets, 2.5 kg steps on the bar and 2 kg per hand on dumbbells, rest 180 / 150 / 120 s. Beat the ceiling — not merely reach it — and the load moves. Zyra Workouts is a training log, and this page is a guide to one movement in its catalog. Educational overview only — not medical advice.