Last updated: October 2026
Fitness OS is built on a principle of absolute data privacy. We collect only what is necessary to operate the service and never sell your personal data to third parties.
| Category | Data | Purpose |
|---|---|---|
| Account | Email address, hashed password | Authentication via Supabase |
| Profile | Age, weight, fitness goal, language preference | Personalizing workout recommendations and recovery calculations |
| Workout Logs | Exercise name, sets, reps, weight, date/time | Progress tracking, SRA recovery modeling, AI analysis |
| App Settings | Theme, timer preferences, Arsenal exercises | Persisting user preferences |
| Device | Browser type, OS (anonymous) | PWA functionality and crash reporting |
We do not collect: GPS location, contacts, camera/microphone access (except Gym Lens with explicit user consent), or any biometric identifiers.
Your workout data is stored in two places:
Supabase is our database provider. Their privacy policy is available at supabase.com/privacy. We enforce Row Level Security (RLS) so your data is accessible only to your account.
When you use AI features (Gym Lens, AI Workout Generator, Weekly Summary), workout statistics (for example exercise names, weights, repetitions, totals) and, for Gym Lens, the photo you take are sent to our Cloudflare Worker proxy, which forwards the request to the OpenAI API for processing. We do not send your email, name, or account ID to OpenAI, and we do not store Gym Lens photos. OpenAI processes this data under its API terms.
Weekly summary notifications are generated from the same kind of statistics and delivered to your device as a push notification, only if you are a PRO user and have allowed notifications.
YouTube video thumbnails are loaded directly from YouTube's CDN. This is subject to Google's Privacy Policy.
Your data is retained for as long as your account is active. You may delete your account at any time from the Setup → Profile tab, which permanently removes all your data from our servers within 30 days.
If you are located in the European Economic Area, you have the right to:
To exercise these rights, contact us at privacy@fitnessos.app.
Fitness OS uses only functional cookies and localStorage for session management and user preferences. We do not use tracking cookies or advertising cookies.
To fix bugs we use Sentry error monitoring (EU data region). It receives technical error reports (error message, browser and device type, app version) and an anonymous account ID; it does not receive your email, workout data, or any session recordings.
The Service is not directed to children under the age of 16. We do not knowingly collect personal information from children. If you believe a child has provided us with personal data, contact us immediately.
We may update this Privacy Policy from time to time. We will notify you of significant changes through the application. Continued use of the Service after changes constitutes acceptance.
For privacy-related inquiries: privacy@fitnessos.app