Currently in beta testing on Android & iOS

▲ TRN

Training Notation

Open format for workout programs

Track your training with location awareness. Import and export workouts freely. No vendor lock-in. Your data, your format.

Get early access

Be among the first to download the app when it launches on Google Play and App Store.

Android firstiOS coming soonFree to use

Built for serious lifters

A workout tracker that respects your time. Track sets, manage programs, and keep your training organized across multiple gyms.

Your training at a glance

See today's workout and what's coming next

Track every set

Rest timer, progress tracking, reorderable exercises

Your program library

Import programs from anyone, anywhere

What is .trn?

A simple, human-readable text format for workout programs. Like Markdown for text or JSON for data, but for training.

arnold-golden-era-split.trn

program: Arnold's Golden Era Split
author: Arnold Schwarzenegger
type: rotation

schedule:
  sequence: [chest_back, shoulders_arms, legs]
  rhythm: "1-1-1-1-1-1-0"

workouts:
  - id: chest_back
    name: Chest & Back
    exercises:
      - name: Bench Press
        sets: 5
        reps: 8-12
        rest: 120s
        
      - name: Pull-ups
        sets: 5
        reps: 8-12
        weight: bodyweight

Share workouts like files

Send a .trn file to a friend, post it on Reddit, or attach it to a YouTube video. Anyone with a TRN-compatible app can import it instantly.

No more screenshots

Stop transcribing workouts from images. Import programs directly from trainers, creators, or the community.

AI-friendly format

Ask ChatGPT to convert any workout to .trn format. The structured syntax makes it easy for AI to generate valid programs.

Open source, MIT licensed

The format specification is free to use. Build parsers, create tools, or implement it in your own app.

Programs from legends and creators

Import programs from your favorite trainers or create your own. The library is growing every day.

Arnold's Golden Era Split

by Arnold Schwarzenegger

6 daysHigh volume

Fundamentals of Hypertrophy

by Jeff Nippard

4 daysScience-based

Starting Strength

by Mark Rippetoe

3 daysBeginner

Perfect Workout Series

by Jeff Cavaliere (Athlean-X)

3 daysFull body

Classic Upper/Lower

Traditional

4 daysIntermediate

Your own program

Created by you

Any scheduleYour rules

Why I built this

I train in multiple gyms. Different equipment, different weights, different everything. I needed to know: what did I lift last time in this specific gym?

Existing apps didn't solve this. Some have location features, but none make it a core part of the experience. And all of them lock you into their ecosystem. Your workout in Strong isn't a workout in Hevy. Your progress is trapped.

So I started building an app for myself. But as I worked on it, I realized the bigger problem: there's no universal way to share workouts. Trainers send PDFs. Creators post screenshots. Everyone is copy-pasting from notes.

TRN is my answer. An open format that anyone can use, and a powerful app to make it useful. The format is free. The app is free. Your data is yours.

Viktor, building TRN solo from Prague

Follow the development

TRN is being built in public. Follow the journey, share feedback, and help shape the future of workout tracking.

Instagram

Discord coming soon

Reddit coming soon

Don't miss the launch

Join the waitlist and be the first to download TRN when it hits the app stores.