Privacy Policy

Last updated: June 10, 2026

Athylos ("Athylos," "we," "us") provides AI-powered swim training for iPhone and Apple Watch. This policy explains what information we collect through the Athylos app, the Athylos Watch app, and this website, how we use it, and the controls you have. The short version: your data powers your own training analytics, anything beyond that is opt-in, and we never sell your data or use it for advertising.

1. Information we collect

Account information

When you sign in with Apple, we receive your Apple user identifier and — on first sign-in only, if you choose to share them — your name and email address. Your training profile (age, weight, height, gender, goal event, best and goal times, training shape, and equipment) is stored on your device and synced to your Athylos account.

Health and workout data

With your permission, Athylos reads swim workouts from Apple Health — including pool length, splits, stroke distribution, heart rate, and energy burned — and records workout data from the Athylos Watch app, including per-rep times, stroke counts, and motion-sensor (accelerometer and gyroscope) samples. This data powers your in-app analytics: fastest splits, trend charts, top-end speed by stroke, and coaching feedback. Apple Health data is used only as described here, is never used for advertising, and is never sold.

Data sent to our servers

To deliver core features, the app sends our servers your AI workout-generation requests, completed-workout summaries, per-rep records, and watch session summaries. Server-side data is keyed to a random user identifier.

Opt-in telemetry

During onboarding you choose whether to share anonymized swim data to help improve Athylos coaching. You can change this choice at any time in Settings → Share Anonymized Data. When the toggle is off, no telemetry leaves your device. Apple Health access, the AI generation requests you initiate, and Sign in with Apple continue to work — they are essential to the app and are not telemetry.

Diagnostics

We collect crash-level diagnostic data to improve stability. Diagnostic data is not linked to your name or email.

Website and beta list

If you join our beta waitlist on this website, we collect the email address you submit and use it only to contact you about Athylos beta access and launch updates. You can unsubscribe at any time using the link in any email or by contacting us.

2. How we use information

• To provide the app: generating workouts, sending them to your watch, and computing your analytics.
• To improve coaching and workout generation, using only data you have opted in to share.
• To maintain reliability and fix crashes.
• To communicate with you about beta access, support requests, and important account or service changes.

We do not sell your personal information, do not use it for third-party advertising, and do not track you across other companies' apps or websites.

3. Service providers

We use a small number of providers to operate Athylos, each bound to process data only on our behalf:

• Apple — Sign in with Apple, App Store billing, TestFlight, and Apple Health (HealthKit) on your device.
• Google Cloud — application hosting, database, analytics storage, and file storage.
• AI model providers — your workout-generation requests are processed by large-language-model providers to produce your workout. Requests are keyed to a random identifier, not your name or email.
• RevenueCat — subscription management. RevenueCat receives your random user identifier and purchase status; it never sees your payment details, which Apple handles entirely.

4. Data retention

• Telemetry events are retained for at most 400 days.
• Motion-sensor data chunks are retained for at most 60 days.
• Workouts, sessions, and aggregated analytics tied to your account are retained for as long as your account is active.
• Beta waitlist emails are retained until you unsubscribe or ask us to delete them.

5. Account deletion

You can delete your account at any time in Settings → Delete Account. Deletion permanently removes your identity record and your saved workouts, sessions, and chat history from our servers. Historical analytics rows are anonymized and age out within the retention windows above. You may sign in again afterward and start fresh. You can also request deletion by contacting us at the address below.

6. Your rights

Depending on where you live, you may have rights to access, correct, delete, or export your personal information, and to object to or restrict certain processing. You can exercise most of these directly in the app (profile editing, telemetry toggle, account deletion); for anything else, contact us and we will respond within the timeframe required by applicable law. We do not discriminate against you for exercising your privacy rights.

7. Security

Data in transit is encrypted with TLS. Server-side data is stored on Google Cloud with access restricted to service accounts that need it. Authentication uses Sign in with Apple with short-lived session tokens. No method of transmission or storage is 100% secure, but we work to protect your information using industry-standard practices.

8. Children

Athylos is not intended for, and may not be used by, anyone under 13 years of age. We do not knowingly collect personal information from children under 13. If you believe a child has provided us personal information, contact us and we will delete it.

9. Changes to this policy

If we make material changes, we will update the date at the top of this page and notify you in the app or by email before the changes take effect. Continued use of Athylos after changes take effect means you accept the updated policy.

10. Contact

Questions or requests? Email us at support@athylos.com or use Settings → Contact Support in the app.