1. Basic information
NEXT8 Performance operates a mobile app available on the Apple App Store and Google Play Store and a web app at next8.app. Protecting your personal data is our priority.
2. Data controller
NEXT8 Performance
Contact: next8performance@gmail.com
3. What data we collect
- Registration data: name, e-mail, password
- Training data: sleep, fatigue, pain, training intensity, notes
- Advanced metrics: heart rate, calories, steps, RPE (optional)
- Technical data: IP address, device type (to ensure functionality)
4. Purpose of processing
- Providing and improving our service
- Creating personalized analytics and recommendations
- Communicating with you about the service
- Ensuring security and preventing misuse
5. Legal basis for processing
- Your consent (signing up for the service)
- Performance of a contract (providing the service)
- Legitimate interest (service improvement, security)
6. Data sharing
We never sell your personal data to third parties. We only share data with:
- Supabase — secure data storage
- OpenAI / Google — generating analytics (anonymized data)
- When legally required (court order)
7. Health data from Apple Health and Health Connect
If you enable the connection, NEXT8 reads selected data from Apple Health (iOS) or Health Connect (Android). The connection is fully optional — without it the app works unchanged. You can revoke access anytime in system settings (iOS: Settings → Privacy → Health; Android: Health Connect app → Permissions).
Data we read (only with your consent):
- Sleep (duration and quality) — to pre-fill your morning log
- Heart rate, resting heart rate and HRV — to refine load and recovery
- Steps and active calories — for a daily activity overview
- Workouts (type, duration, heart rate, calories) — for automatic import into your log
Data we write:
Workouts recorded in NEXT8 can (with write consent) be saved back to Apple Health / Health Connect.
How we handle this data:
- We use it solely for the app features above (metrics, NEXT8 index, recommendations)
- We never sell it or share it with third parties for advertising or marketing
- We never pass Apple Health / Health Connect data to AI providers (OpenAI) — only anonymized subjective logs go into generating recommendations, not health values from your watch
- We never use Apple Health / Health Connect data for advertising profiling
- After account deletion it is permanently removed within 30 days (see sections 9 and 10)
Handling of Health Connect data complies with Google Play’s Health Connect policy and Apple’s HealthKit rules.
8. How long we keep data
For as long as you use the service. After account deletion, data is permanently removed within 30 days.
9. Your rights (GDPR)
- Access: request a copy
- Rectification of inaccurate data
- Erasure: delete your account and all data
- Portability: export data (CSV/PDF)
- Objection to processing
- Withdraw consent anytime
To exercise your rights: next8performance@gmail.com
10. Account deletion
In the mobile app: Profile → Settings → Delete account.
Or by e-mail to next8performance@gmail.com with the subject “Account deletion”. All data is permanently deleted within 30 days.
11. Security
Passwords are hashed, communication runs over HTTPS, and data access is strictly controlled.
12. Cookies
The mobile app uses no cookies. The web app uses only essential login cookies. The marketing website next8performance.cz uses Google Analytics (GA4) analytics cookies for anonymous traffic measurement — they run only after your consent in the cookie bar, your IP address is anonymized and you can withdraw consent anytime. We use no marketing or advertising cookies.
13. Contact and complaints
E-mail: next8performance@gmail.com
You have the right to lodge a complaint with the Czech Data Protection Authority (ÚOOÚ): www.uoou.cz
Last updated: 17 April 2026
