---
title: 'How-to Guides'
description: 'Short step-by-step guides for concrete needs: sharing, backup, sync, and tips.'
slug: 'how-to-guides'
weight: 2
date: 2026-06-16
---

## Install TrainUs as an App on Android

TrainUs is a Progressive Web App (PWA): it installs as a real app on your phone, with its own home screen icon, and runs without the browser's navigation bar.

> **Important:** if TrainUs is already open in a browser tab, the installed app may not launch correctly — the browser and the installed app conflict with each other. Close the browser tab first before launching the installed app.

### With Firefox

1. Open TrainUs in Firefox.
2. Tap the **⋮** menu (top right).
3. Tap **Install** or **Add to Home Screen**. If you don't see this option, tap **More** first to reveal all available actions.
4. Confirm by tapping **Add**.
5. The TrainUs icon appears on your home screen.

### With Chrome

1. Open TrainUs in Chrome.
2. Tap the **⋮** menu (top right).
3. Tap **Add to Home Screen** or **Install App**.
4. Confirm by tapping **Install** or **Add**.
5. The TrainUs icon appears on your home screen.

### If the icon is wrong or the app won't launch

In some cases the icon displayed is incorrect, or the app refuses to open. To start fresh:

1. **Uninstall** the app (long-press the icon → Uninstall).
2. Open **Android Settings → Apps** and find your browser (Firefox or Chrome).
3. Tap **Clear Cache** (or **Clear Data** if the problem persists).
4. If the problem still persists, **restart Android**.
5. Reopen TrainUs in the browser and reinstall the app.

## Send One or More Sessions to a Friend

1. Open the **Sessions** list.
2. Click the download icon in the action bar to export every session, or open a single session and click the same icon to export just that one.
3. A dialog suggests a file name (e.g. `trainus-sessions-2026-06-16`); confirm or rename it, then the `.json` file downloads.

It's a perfectly normal text file: you can email it, drop it on a shared drive, or send it through WhatsApp like any other attachment.

## Import a JSON File From a Friend

1. On the matching list (or from **Settings → Import Data**), click the import icon and pick the `.json` file.
2. Since the file comes from another user, TrainUs asks you for a short suffix (e.g. "JD"): every imported title will display with that suffix ("Push-ups [JD]"), so it never mixes with your own exercises.
3. A summary screen shows what will be imported before anything changes. Confirm to finish.

See the [Reference]({{< relref "user-guide.en.md" >}}) for the details of each screen and how suffixes are managed.

## Share the Home Page as HTML

Once you have a bit of history, a **`</> HTML`** button appears in the home page's action bar. It generates a single self-contained HTML file (images included) with your statistics and recent history — handy to email or print, with no active links or buttons.

This is useful for sharing your activity with a friend, but it's mainly designed for your **coach**: they can follow your training history without installing TrainUs or accessing your data — you just send them this one file.

## Back Up Your Data

Two levels of backup, depending on the need:

- **Full backup** (recommended regularly): **Settings → Download Database**. This produces a `.sqlite3` file containing absolutely everything. TrainUs reminds you to do this if your last backup gets too old.
- **Selective backup**: a JSON export (see above) of a single data type — useful before a risky change, or to back up only your sessions for example.

To restore a full backup: **Settings → Restore Database** — see the [Reference]({{< relref "user-guide.en.md" >}}). Keep in mind that restoring **replaces** all your current data.

## Sync Two Devices

TrainUs doesn't automatically sync anything between your devices (no server — see [Understanding TrainUs]({{< relref "comprendre.en.md" >}})). Two manual methods, depending on your need:

**Mirror method — one device takes over the other**

1. On the most up-to-date device: **Settings → Download Database**.
2. Transfer the `.sqlite3` file to the other device (email, drive, USB key...).
3. On the other device: **Settings → Restore Database**, select the file.

Careful: restoring **replaces** all of device B's data with device A's — this is not a merge, it's one-way. Repeat the operation whenever you want to bring both devices back in sync, always from the one you used most recently.

**Merge method — keep what exists on both devices**

If both devices have their own data you want to keep, use JSON export/import per entity type instead of the full database. On import, use the **"Import as Mine"** button to avoid adding a suffix. TrainUs then detects items that already exist (same ID) and lets you choose, one by one or in bulk, to **replace** or **keep** your version.

> **Note:** the user ID does not sync automatically between devices — only a prior full database transfer (mirror method) guarantees that both devices share the same user record.

## Tip: Yoga

For a yoga session, it's often simpler **not to split each posture into a separate exercise**: create a single "Yoga session" exercise (or one per sequence), with the description or images for the whole flow. Easier to manage, and closer to how you actually practice it.

## Tip: Running

TrainUs isn't built for run tracking, but you can run for a set time with the existing tools: create a "Run" exercise with 1 repetition, put it alone in an **AMRAP**-type combo, and set the AMRAP duration to the time you want to run. The timer will count down for you.