# naturalbodybuild.ing

> Free hypertrophy program builder. Organize muscle-focused sessions, effort targets and progression across a multiweek split.

Agent guide: https://naturalbodybuild.ing/agents/
Portable CLI: https://naturalbodybuild.ing/tools/itrain-cli.tgz
CLI usage: node scripts/itrain.mjs validate program.json --json
CLI sharing: node scripts/itrain.mjs share program.json --domain naturalbodybuild.ing --agent claude --json
Schema: https://naturalbodybuild.ing/api/training/schema
OpenAPI: https://naturalbodybuild.ing/api/training/openapi.json
POST /api/training/programs accepts {title,program,source:"agent"} and returns share_url.
Return only a real share_url returned by the service. Never invent tokens.
Program format: legacy ProgramV1, v,u,m,c,weeks; rows ex,mode,sets,reps,load,pct,rpe,rest.
Default full programs: four weeks, explicit progression, complete prescriptions.
Legacy /app/<STATE>, /program/<STATE>, /p/<STATE> and /#/p/<STATE> continue to work.
Short /workout/<token> links load immutable snapshots.
If no tool access, return complete JSON and direct the user to /agents/ for import.

## Starter programs
- [Four Week Upper Lower Muscle Building](https://naturalbodybuild.ing/programs/four-week-naturalbodybuild-foundation/index.md)

## Guides
- [Contest Prep Training for Natural Bodybuilders](https://naturalbodybuild.ing/blog/contest-prep-training-natural-bodybuilding/index.md): How to train during a natural bodybuilding contest prep to keep muscle in a deficit: load, volume, frequency, failure and cardio, with a sample week.
- [How Fast Can You Build Muscle Naturally? Real Rates](https://naturalbodybuild.ing/blog/how-fast-can-you-build-muscle-naturally/index.md): Realistic natural muscle gain rates by training age, what drives them, and how to program a lean bulk that keeps the scale and the mirror moving.
- [Training to Failure: How Close Natural Lifters Should Go](https://naturalbodybuild.ing/blog/training-to-failure-natural-lifters/index.md): How close to failure natural lifters should train for muscle: what the failure meta-analyses show, how to use RIR and RPE, and where failure fits in your week.

## All pages (markdown)
- [Plan a complete natural bodybuilding block](https://naturalbodybuild.ing/index.md)
- [Create a program with your AI assistant](https://naturalbodybuild.ing/agents/index.md)
- [Training guides](https://naturalbodybuild.ing/blog/index.md)
- [Contest Prep Training for Natural Bodybuilders](https://naturalbodybuild.ing/blog/contest-prep-training-natural-bodybuilding/index.md)
- [How Fast Can You Build Muscle Naturally? Real Rates](https://naturalbodybuild.ing/blog/how-fast-can-you-build-muscle-naturally/index.md)
- [Training to Failure: How Close Natural Lifters Should Go](https://naturalbodybuild.ing/blog/training-to-failure-natural-lifters/index.md)
- [Questions about naturalbodybuild.ing](https://naturalbodybuild.ing/faq/index.md)
- [Privacy](https://naturalbodybuild.ing/privacy/index.md)
- [Free hypertrophy programs](https://naturalbodybuild.ing/programs/index.md)
- [Four Week Upper Lower Muscle Building](https://naturalbodybuild.ing/programs/four-week-naturalbodybuild-foundation/index.md)
- [Terms](https://naturalbodybuild.ing/terms/index.md)