Add a custom exercise to your library

Your gym has a hack-squat-row machine that nobody else has. Or you've got a name for the lift your coach taught you that doesn't match anything in the catalog. You add it to your library once, with the details that matter, and from then on you can queue it in routines and log sets like any other exercise.

What the agent needs to hear

Behind your sentence, the agent works backwards to three pieces: the exercise name — the one you’ll recognise when you search — the primary muscle group (quad, hamstring, chest, biceps, lat), and the equipment (barbell, dumbbell, cable, machine, bodyweight). « Hack-squat-row, quad-primary, machine » lands all three.

Optional pieces — movement pattern, secondary muscles, setup notes for future-you — slot in if you provide them. « Smith-bar RDL, hamstrings, barbell, hinge pattern » fills more of the frame. The agent shows a preview card with the new entry and asks you to confirm before saving.

What auto-fills vs what you provide

Primary muscle is mandatory — it’s what drives substitute suggestions when you ask « what can I swap for this ». Equipment is mandatory too — it’s what powers gym-availability filtering when you train somewhere else and need to know what’s possible.

Movement pattern (squat, hinge, push, pull, carry) auto-infers from name plus muscle when the signal is clear — « Romanian deadlift, hamstrings » resolves to hinge without you naming it. Override when the inference is wrong and the agent corrects in place.

Secondary muscles are auto-suggested from the primary; name them or leave the suggestion. Setup notes are optional — useful for lifts with a cue you’ll forget in three weeks (« stand 6 inches in front of the rack, low-bar position »).

What this library entry enables

A saved custom exercise shows up in your library next to the catalog exercises. From there it flows into everywhere exercises live: routine days (queue it in any day’s template alongside catalog lifts), session logs (working sets, rest-pause, drop sets, every cluster type), substitute suggestions (the agent considers it when you ask for a swap), and PR detection (the lift accumulates its own PR ledger from the first logged set forward).

Custom exercises are private by default — only you see and use them. They behave as first-class lifts in your data: same volume math, same progression curves.

When the agent gets it wrong

The preview card is where things get caught. If the name collides with an existing entry — you said « hack-squat-row » and the catalog already has a similarly-named lift — name the intent: « create a new entry, this is the gym’s machine, not the catalog one ». The agent splits them.

If the muscle group is wrong (the agent attached « hamstring » to a clearly quad-dominant lift), correct it directly: « that’s quad-primary, not hamstring — hamstrings are secondary at most ». And if the inferred movement pattern doesn’t fit (« it’s a horizontal pull, not a squat — that machine is misnamed »), name the correction; the agent re-classifies and the preview updates.

What makes the library entry worth keeping

Three things decide whether this exercise is useful tomorrow: the name is one you’ll recognise when you search (« coach’s curl variant » beats « Custom Exercise 1 » when scrolling a long library), the muscle group is accurate (a quad-primary lift tagged as hamstring corrupts both the PR ledger and every substitute suggestion downstream), and the equipment matches what you actually need (a machine entry that’s secretly a barbell lift breaks gym-availability filtering the moment you travel). Save it carefully once and the lift becomes a first-class movement in your training — queued, logged, and progressed exactly like anything from the catalog.