Last updated: 4 November 2026
Muscle Train (“we”, “the service”) is a training-program generator and workout tracker available at muscletrain.app. This page explains what personal data we collect, why we need it, and what control you have over it.
For any privacy question or request, write to [email protected].
Your email address and username. If you register with a password, we store only a cryptographic hash of it — never the password itself. If you sign in with Google or Apple, we store the identifier that provider gives us instead of a password. We also keep your registration date, when you last signed in and last used the app, and whether your email is confirmed. If you arrived through a link that names its source (for example a forum post), we record only the name of that channel — such as “reddit” — with your account, to see which channels bring people.
The details you enter so programs can be generated: age, sex, height, body weight, fitness level, training goal and available equipment.
Programs you generate or build by hand, completed workouts (exercises, sets, reps, weight, hold time, perceived difficulty, notes), notes you keep on exercises, exercises you mark as favorites or ask us never to suggest, ratings you give programs, your answers to the question about how accurate the muscle-fatigue estimate is (together with the percentages it showed you), body-weight entries, goals, 1RM test results and progression progress. While you are logging a workout, a copy of what you have entered so far is also kept on our server, so you can pick it up on another device. It is deleted when you save the workout or delete your account; a copy you haven’t touched for 14 days is no longer offered to you.
Only if you choose to fill it in: a short description of an injury, the muscle area, the month it started, how many times it came back and how it feels now. You write this for yourself, so the app can remind you not to push those muscles while they still bother you. It is never shown in the activity feed, never shared with anyone, and you can delete any entry at any time.
If you use the feedback form: your message and its category, and — only if you choose to provide them — your email address and any screenshots you attach.
If you suggest an exercise: what you wrote in the form, the language of the page and when you confirmed that the text is your own. Suggestions are linked to your account so you can follow their status, and are deleted together with it.
When you change settings on the Reminders page, we store the times, days and time zone of your reminders (as your browser reports it; it is refreshed when you open the page) and the language of the page, so reminders arrive at your local time and in your language. For each device where you allow notifications, we store the push subscription your browser gives us (an address at your browser's notification service and encryption keys) and whether that service has been refusing it. For each reminder we keep a record for 7 days — the date, the time and whether it was delivered — so that no reminder is sent twice and we can find out why one didn't arrive. We use all of this only to send the reminders you asked for. The reminder text is encrypted and delivered through your browser's notification service — Google for Chrome and the Android app, Apple for Safari, Mozilla for Firefox, Microsoft for Edge on Windows. To stop, switch reminders off on the Reminders page, stop them on a device, sign out on that device, or block notifications in your browser or phone settings; deleting your account deletes all of it.
Cookies (listed below) and standard server logs.
We do not collect payment data, we do not build advertising profiles, and we do not sell your data to anyone.
Strictly necessary — always set, the site cannot work without them:
access_token — keeps you signed in (expires 7 days after your last visit)csrf_token — protects forms against cross-site request forgerycookie_consent — remembers your cookie choicePreferences — remember how you like the site, never shared:
theme — dark or light appearance, so the page opens the way you left it instead of flashing the wrong colourslang — the language you chose, so every page opens in ittz_offset — your device’s time zone offset, so your day and training week follow your phone rather than the server’s clockOptional — analytics cookies, set only if you agree. You can change or withdraw your choice at any time via “Cookie settings” in the footer.
Local storage — the app also keeps a few entries in your browser’s own storage:
mt_last_login_method) so it can mark it on the button;mt_worklog_…, mt_freelog, mt_editlog_…, mt_draft_seen — what you have entered in a workout you haven’t saved yet, so nothing is lost if the page reloads or the phone closes the app, and when each draft was last opened — drafts nobody has touched for 30 days are removed;mt_exreq — an exercise suggestion you are still writing, so it isn’t lost if the page reloads; it is deleted once you send it, or after 30 days without changes;mt_lang_keep — what you have entered or picked on the page — typed fields, ticked filters, a program you are building — while you switch the language, so it isn’t lost when the page reloads in the new language; it is erased as soon as the page has reloaded, and passwords are never kept;mt_gen_draft — a program you have generated but not started yet, so it isn’t lost when you open an exercise and come back; it is removed when you start or discard it, or after 7 days;mt_gen_leave — your answers in the program generator when you go from it to “My Equipment”, so they are still there when you come back; they are erased as soon as the generator page opens again or you return to it, are not used after 30 minutes and live only as long as the browser tab;mt_workout_summary — the summary of a workout you have just saved, so the page you land on after saving can show it; it is erased as soon as it has been shown, is not used after 10 minutes and lives only as long as the browser tab;mt_admin_wf_… — only for administrators: a task in the admin task list that is still being written, so it isn’t lost if the page reloads; it is erased once the server confirms it was saved, and it lives only as long as the browser tab;mt_workout_prefs — workout-timer settings on this device: preparation time, sound and rest length;mt_progress_exercises_… — the exercises you picked on the Progress page, kept separately for each account on this device, so your choice is still there next time;mt_level_range — how many weeks the level chart on the Progress page shows, so your choice is still there next time;mt-map-view — where you last looked at the places map, so it reopens there;mt_install_bar, mt_inventory_tip_hidden, mt_moved_note_seen, mt_reminder_offer_seen, mt-rating-asked-… — whether you have closed the install banner or a tip, and which programs you have already been asked to rate.These entries stay in your browser and are not sent to us — except the copy of an unfinished workout described under “Training data” — and clearing your browser’s site data removes them. The installed app also keeps copies of its own files and of the public exercise list so it can open without a connection; your personal pages are not stored there.
You can optionally upload a profile photo. It is resized and stored in Cloudflare R2 (object storage) and served over Cloudflare's CDN; the image URL is public, so anyone who has the link — or sees your photo in the app or the activity feed — can view it. We don't store the photo on our own server or in the database (only a reference to it). Remove it any time from your cabinet.
The app has an optional community feed. Sharing is off by default — your activity appears in the feed only if you turn it on (Feed page → “Share my activity”). When enabled, other signed-in users can see when you complete a workout, reach a goal, finish a program or advance a progression: your username, the item’s name and light details (e.g. exercise count, difficulty). We never put weights, body weight or other numbers in the feed. Turn sharing off any time to stop adding new events.
You can hide another person’s posts and shared programs from yourself; we store whom you hid until you show them again, and that person is not told. If you report a post, a program or a place, we keep the report with your feedback, together with a reference to what you reported.
If you add a place to the map (for example a street-workout park) or report what equipment a place has, that information — the place’s name, type, location and equipment — is visible to everyone who uses the map. Your username is not shown with it. We don’t store your own location: the “Near me” search runs in your browser. If you delete your account, the places you added stay on the map without any link to you; you can remove them before that.
These providers process data under their own privacy policies.
We keep your data for as long as your account exists. Programs and logs you delete are marked as deleted and removed during routine cleanup. If you ask us to delete your account, we remove your personal data.
Write to [email protected] and we will respond as soon as we can.
The service is not intended for children under 16. Creating an account requires confirming that you are 16 or older.
We may update this page; the “last updated” date above will change accordingly. Significant changes will be announced in the app.
See also our Terms of Service.
Muscle Train is actively being built. If something looks broken, or you have a suggestion, let us know — it really helps shape the app.