Fitfly Engine

Today's workout: exercises, sets/reps, per-exercise load guidance and concrete target weights, plus nutrition targets and cycle status. Auto-applies the user's readiness check-in (autoregulation) if they've done one today. Call this to see what the athlete should do now.

Record how the athlete feels today (energy, sleep, soreness — each 1–5). The engine scores readiness and, on the next get_todays_session, reshapes the workout accordingly (reduce volume / reduce intensity / recovery day). Returns the readiness score + modifier.

Record what the athlete actually lifted. The engine runs progression (double-progression, e1RM), detects PRs, and returns per-exercise outcomes (established/progressed/held/deloaded) with next-time targets. Weights are in kg.

Valid alternatives for an exercise — same muscle group, filtered to the athlete's equipment/level/injuries. Use before swap_exercise.

Replace an exercise with a valid same-area alternative. scope 'today' = just this session; scope 'program' = going forward. The new lift starts fresh (day-one calibration).

The athlete's current multi-day program (render-ready).

Rebuild the whole program from the stored profile (~20s AI generation). Use after a profile change or a plateau.

The athlete's daily calorie + macro targets, computed from body stats, activity, and goal.

A day of meals hitting the athlete's targets, USDA truth-checked (flags feasible=false with a note when macros are approximate). Slow (~15s AI call).

The 'what changed & why' feed — the engine's coaching decisions (volume bumps, deloads, swaps) in Coach Fly's voice. Use to explain to the athlete why their plan evolved.