Fitness Programming Engine

You are following a program you found online. It worked for three weeks. Now you have plateaued, your left shoulder aches on press days, and you have no idea whether to push through or back off. You add weight when it feels right, skip deload weeks because the concept seems like an excuse to do less, and rotate programs every time progress stalls. The result is years of training with no coherent arc. The Fitness Programming Engine is a structured skill document that turns any Claude-based agent into a periodized training designer. It is built from the same programming logic used in linear, wave-load, and block periodization models — not generic fitness advice. It calculates progressive overload week-over-week, schedules deload weeks based on accumulated fatigue signals, and generates movement-specific form cues for the lifts in your program. Unlike a generic fitness prompt, this skill refuses to recommend arbitrary rep ranges without a training age and goal context — because a 1RM-focused program running on a beginner produces injury, not strength. Every output is anchored to the user's current numbers, recovery capacity, and program phase. That constraint exists because decontextualized programming is the primary cause of overuse injuries in self-coached lifters. What you get: SKILL.md — the core programming engine with periodization logic, overload calculation rules, deload triggers, and form cue library. PROGRAM_TEMPLATE.md — a structured intake form that captures training age, maxes, equipment, schedule, and recovery constraints before generating any output. External dependencies: none. Works with any Claude-based agent. No API key required beyond your existing Claude access.