Privacy policy

Last updated: October 21, 2026

In short. Stamio does all its calculations on your iPhone and Apple Watch. Your health data never leaves your devices: no account, no server, no ads, no analytics. Nothing is sold or shared.

Who makes Stamio

Stamio is made by Charles Lapointe, an independent developer based in France. For any question about your data: contact@stamio.app.

What Stamio reads from Health

With your permission, Stamio reads from Apple's Health app:

• your workouts: type, duration, distance, GPS route, heart rate, running power and stride, effort rating;
• your heart: heart rate, resting heart rate, heart rate variability (HRV) and beat-to-beat intervals;
• your nights: sleep and sleep stages, respiratory rate, wrist temperature, blood oxygen;
• your day: steps, active energy, and the VO2 max estimated by Apple (only to compare);
• your profile: age, sex, weight, height, BMI, wheelchair setting.

Each piece of data feeds a calculation: VO2 max, training load and status, readiness, energy, sleep score, race predictions, training plan. You choose what you share in the Health sheet, and you can remove access at any time in Settings › Apps › Health › Data Access & Devices › Stamio. Values that depend on it then no longer appear.

If you pair a chest strap (advanced setting), Stamio reads its heart rate over Bluetooth during your runs, on your iPhone only.

What Stamio writes to Health

Only what you enter yourself: your naps, weight, height and how hard a workout felt. Stamio never writes its own estimates (VO2 max, readiness, energy…) to Health.

Where your data lives

• Calculation results (your VO2 max history, training loads, training plan, settings) are stored in the app, on your iPhone. They are sent to your Apple Watch through Apple's iPhone–watch connection, so the watch shows the same values.
• Stamio has no server and sends nothing over the internet. The app contains no third-party analytics, advertising, tracking or crash reporting tools.
• Like any app, these files are part of your iPhone backup (iCloud or computer) if you turned it on. That backup is managed by Apple.
• Nothing leaves Stamio unless you ask: plan workouts sent to the Workout app on your watch, and the plan PDF if you choose to share it.

How long

As long as the app is installed. Settings › Data › "Delete app data" erases everything Stamio stored (calculations, plan, settings) without touching Health. Deleting the app does the same. What you wrote to Health stays in Health, where you can delete it.

Your rights

None of your data ever reaches us, so we hold nothing about you and there is nothing to access, correct or erase on our side. Everything is managed in the app and in Health. For any question, write to us (contact@stamio.app). You can also file a complaint with the French data protection authority, the CNIL (cnil.fr).

If this changes

If a future version ever needed data to leave your devices (for example an online backup or a test program), this policy would be updated first, and the app would clearly ask for your consent. Without it, nothing would be sent.

Not a medical device

Stamio is not a medical device. It does not diagnose, treat or prevent any disease. Its values are estimates to help you train. If you have any doubt about your health, talk to a doctor.