Privacy Policy
Effective date: March 4, 2026
Duro is operated by EP Studios ("we", "us", "our"). This policy explains what data we collect, why, and how we handle it.
1. Data you provide
When you use Duro, you may log:
- Workout data — exercises, sets, reps, weight, RPE, effort scores, and notes
- Custom exercises and workout templates
- Preferences — theme, units, rest timer duration, and other settings
On our website, you may provide your email address to join the waitlist.
2. Data collected automatically
With your permission, Duro reads:
- Heart rate — streamed from Apple Watch during workouts
Duro does not collect location data, device identifiers, contacts, photos, or browsing history.
3. How we use your data
On-device processing
All workout history, templates, custom exercises, and preferences are stored locally on your device using Apple's on-device database. This data stays on your device and is protected by iOS encryption.
Server processing
Duro sends workout data to our servers to provide app features such as personalized coaching and training insights. The data we transmit may include:
- Workout history — exercises, sets, reps, weight, and performance metrics
- Training analytics — volume per muscle group, recovery status, training load, and strength trends
- Workout metadata — titles, dates, duration, and effort scores
Third-party AI processing
We forward workout data to third-party AI model providers to generate personalized coaching messages and training insights. This data is sent in aggregate or summary form and does not include your name, email, or other personal identifiers. Our AI providers process this data solely to generate responses for you and do not use it to train their models.
Apple HealthKit
With your permission, Duro writes completed workouts and effort scores to Apple Health. Duro reads heart rate data from Apple Watch during active sessions. We do not sell, share, or use HealthKit data for advertising or marketing. HealthKit data is never sent to our servers.
4. Data sharing
We do not sell your data. We share data only with:
- AI model providers — to generate coaching messages, as described above
- Infrastructure providers — our servers are hosted by third-party cloud providers who process data on our behalf
- Apple HealthKit — only with your explicit permission
We do not use advertising networks, analytics SDKs, or tracking pixels in the app.
5. Data export
You can export your full workout history as a CSV file at any time from the app's settings. This file is generated on your device and shared using the standard iOS share sheet.
6. Data retention
On-device data persists until you delete it from the app or uninstall the app. Workout data sent to our servers is retained only as long as necessary to provide the service and is not stored permanently.
7. Security
All data stored on your device is protected by iOS encryption. All network communication uses HTTPS (TLS 1.2+). We do not store passwords or account credentials — Duro does not require an account.
8. Children
Duro is not directed at children under 13. We do not knowingly collect data from children.
9. Changes
We may update this policy. The effective date at the top will reflect the latest revision. Continued use of Duro after changes constitutes acceptance.
10. Contact
Questions about this policy? Email us at privacy@trainduro.com.