Core exercises compared: plank, hanging leg raise, ab wheel, cable crunch, Pallof press

There is no single best core exercise, because the seven core movements in the Zyra Workouts catalog do different jobs: some resist the trunk bending, one resists it extending, two bend it under load, one resists rotation and one rotates. This guide lays them side by side on the criteria the app actually stores — equipment, category, rest, what progresses and how the sets are counted — so you can pick by the job rather than by a ranking. It crowns nothing.

Seven core movements side by side

All seven credit 1 set to core per working set against a 10-set weekly landmark. The "trunk job" column is a mechanical description, not a catalog field — the catalog knows only the muscle, the equipment, the category and the rest.

Muscles worked

Every row is filed under core as the primary. The catalog's secondaries are worth knowing because they show up on the dashboard: a plank, ab wheel rollout or Pallof press adds 0.5 set to shoulders (they hold the arms rigid against the floor, the wheel or the cable), and a hanging leg raise adds 0.5 set to forearms (you are hanging from a bar). A week of three sets each of all seven is 21 core sets — twice the landmark — plus 4.5 shoulder sets and 1.5 forearm sets, before any squat or press adds its half-credits. The weekly sets calculator does that sum.

Setup and execution

Mechanical cues; one line each, because the point of a core movement is holding a shape.

• Plank. Forearms down, elbows under shoulders, body one straight line from ears to heels, ribs down, glutes tight. The rep is the hold.
• Hanging leg raise. Hang from a bar, shoulders set, raise the legs (bent or straight) until the hips curl up, lower under control without swinging.
• Ab wheel rollout. From the knees, wheel under the shoulders, roll out as far as you can hold a flat trunk, pull back with the abs rather than the hips.
• Cable crunch. Kneel facing a high pulley, rope at the forehead, curl the trunk down by folding the ribs toward the hips — the hips stay still. Log the stack.
• Pallof press. Stand side-on to a chest-high cable, hands at the sternum, press straight out and hold; the cable tries to turn you and you do not turn. Log the stack; do both sides.
• Russian twist. Seated, trunk leaned back, feet down or up, rotate the shoulders side to side without the hips following. A rep is one side.
• Hollow body hold. On the back, lower back pressed into the floor, arms and legs extended and hovering, ribs down. The rep is the hold.

Logging holds and bodyweight

A logged set in the app carries a weight and a rep count; there is no seconds field. So a plank or hollow hold is logged as a rep count you define — entering seconds in the reps field is the common convention — and the only rule is to keep it the same convention every time, because the progression engine compares last time's reps to a ceiling. For the five bodyweight rows the load step is 0, so the recommendation can only ever move reps: beat the ceiling and it advances your reps within the range; there is no "add 2.5 kg". If you hold a plate on a rollout or a dumbbell on a twist, log it as the weight and the engine treats it as added load.

The catalog also stores a bodyweight fraction for the bodyweight rows (plank 0.6, hanging leg raise 0.5, ab wheel 0.6, Russian twist 0.5, hollow hold 0.5). It is used by the insights screen to normalise volume — scale weight × fraction + added load, × reps — so a bodyweight set is not counted as zero kilograms moved. Those fractions are the app's estimates, not measurements.

Rep and RIR targets by goal

Two of the seven — the hanging leg raise and the ab wheel rollout — are compound rows and get the compound table:

The other five are isolation rows and get the isolation table:

The rep ceiling is the number the app compares your last set against: the midpoint of the rep range plus the RIR target (round((min + max) / 2) + RIR). RIR is reps in reserve — how many more reps you could have done. These targets are the app's defaults, not a law; a program you build yourself can set anything. For a plank logged in seconds, "10–15 @RIR 1" is obviously not fifteen seconds — set your own targets on the row (the generator's table is a default for rep-based rows, not a claim about holds).

How progression steps on this exercise

Bodyweight rows: step 0, reps only. Example on the general target (8–12 @RIR 2, ceiling 12) for the Russian twist: 14 reps last time → the recommendation is 12 reps, the top of the range, with reason "progress"; fewer than 8 → back to 8. Cable rows step 2 kg on the stack like any other cable exercise, but the two cable core rows are deliberately not loadable in the app's page model — there is no estimated-1RM or load-chart page for the cable crunch or the Pallof press, because a crunch single is not a meaningful number. This is arithmetic, not a trial result.

Alternatives

Every core row's swap list is simply the other six, ranked by the usual rule (feasible, same category, same equipment, then name). For the plank that order is hollow body hold, Russian twist, cable crunch, Pallof press, ab wheel rollout, hanging leg raise; for the hanging leg raise it starts with the ab wheel rollout (the only other compound bodyweight row). Because the list ignores what each movement resists, a swap from a Pallof press (anti-rotation) to a plank (anti-bending) is a change of job — the table at the top is the better guide.

The short version

Seven rows, one muscle bar, different jobs. Bodyweight rows progress by reps (step 0); cable rows step 2 kg and have no 1RM pages. Holds are logged as a rep count you define and keep. Pick by what you want the trunk to resist; the app counts them all the same. Educational overview only — training guidance, not medical advice.