Gymbro · free · open source

Turn the AI you already pay for
into your personal trainer.

It's one prompt. Gymbro gets to know your body, your gym and your goals, then plans every session, remembers your numbers and tracks your progress. It runs right inside the Claude or ChatGPT app, so it's on your phone at the gym and your laptop at home. And yes, it's free.

How it works
~10 min, setup and interview Free GitHub account A paid Claude or ChatGPT plan No coding, promise
9:41●●●
🏋️
Gymbroyour coach

A real session, on loop

How it works

Paste once. Train forever.

STEP 01

Quick setup

Gymbro creates a private folder for your training data (a free GitHub repo) so your workouts save on their own and sync between phone and laptop. It walks you through every step, even if you've never touched GitHub.

STEP 02

Interview

A proper chat about your experience, your gym, your goals, that dodgy knee, and the stuff you love and hate doing. That's how the plan ends up genuinely yours instead of some copy-paste template.

STEP 03

Start lifting

Tell it you're at the gym. It hands you the session with exact weights. You log your sets by typing, talking, or snapping a photo. It saves everything. That's the whole job.

The prompt

Paste this into Claude Code or Codex.

paste as your first message 
Loading the prompt...

Where does this go? Into Claude Code or ChatGPT Codex (Codex is built into the ChatGPT app), not the normal chat window. Paste it as your first message and it takes over from there. It's long on purpose, that detail is what makes your coach good, and one tap copies all of it. Drop it in the wrong place and it'll politely point you to the right one.

The questions everyone asks

Straight answers.

So what actually is Gymbro?
One prompt. You paste it into an AI coding app once, it interviews you, and from then on it's your coach. Behind the scenes it writes your plan into a few plain files (your profile, your gym kit, your program, your logbook) and reads them back at the start of every session, so it always knows exactly where you left off. Nothing to install beyond the AI you already use.
Is it actually good, or just a gimmick?
It's built to a real standard: progressive overload, sensible volume, proper warm-ups, deloads, and hard safety rules. It won't hand you "1000 push-ups", won't program through an injury, and won't help you crash-diet. The aim is a plan a qualified trainer would look at and nod. It won't replace a great coach standing next to you fixing your form, but for planning, logging, and getting stronger over months, it genuinely holds up.
How does it remember my progress?
Every set you log gets written to your own logbook. Next session it reads your last numbers and sets your targets from there. Grind and miss reps, it backs off. Breeze through them, it adds weight. Months in, you can ask things like "how's my bench trending?" or "did I just hit a PR?" and it answers from your real history.
Which AI tools work, and do I need to pay?
Yes, a paid plan, but a normal tier is plenty for a few sessions a week: Claude Pro/Max for Claude Code, or ChatGPT Plus/Pro for Codex (Codex is built right into the ChatGPT app). GitHub is free. So there's no trainer bill, just the AI you probably already pay for. Plain ChatGPT without Codex won't fully work, and a newer, smarter model gives noticeably better coaching.
Can I really run it from my phone?
Yep. Open the Claude Code app (or the ChatGPT app and pick Codex), open your Gymbro folder, and tell it you're training. Because your data lives in that GitHub folder, your phone and laptop always see the same thing. It also speaks whatever language you write in.
Where do I run it, and how do I know it saved?
Anywhere you have Claude Code or the ChatGPT Codex app, on your phone or laptop. You can keep everything in one ongoing chat, or start a new one and it picks up where you left off. It saves your progress automatically after every session and tells you plainly, something like "great session, saved ✓". You never touch a single file.
Is my data private?
Yes, completely. Gymbro is just a prompt: it runs in your own AI account and your data lives in your own private repo, so I never see it, touch it, or store it. Nothing is shared or posted anywhere, and because it's open source you can read exactly what the prompt does before you run it.
One small thing

If Gymbro helped you out.

Gymbro is free and always will be. No pressure at all, but if it saved you a trainer's fee, a star or a protein shake would honestly make my week.

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