Privacy Policy

Last updated: 2026-09-19

1. Who We Are

Muskl is an AI-powered workout planning application published by MSL Innov SAS, registered at 5 rue des boutons d'or, 81380 Lescure-d'Albigeois, France.

Contact email: [email protected]

2. Data We Collect

We collect the following data when you use Muskl:

  • Account data: email address, username, password (hashed).
  • Profile data: age, gender, height, weight, fitness goals, experience level, declared injuries or limitations.
  • Workout data: exercises performed, sets, reps, loads, session duration, performance feedback.
  • Technical data: device type, operating system, device identifier, IP address, crash and diagnostic data.
  • Usage data: app interactions, features used, timestamps.

3. How We Use Your Data

  • Generate personalized workout programs through our AI engine.
  • Adapt and improve your sessions based on your performance.
  • Manage your account and provide the service.
  • Send service-related communications (confirmations, updates).
  • Improve and develop our product using aggregated, anonymized data.
  • Ensure security and prevent fraud.

4. Legal Basis for Processing (GDPR)

  • Contract performance: processing necessary to provide you with the Muskl service.
  • Legitimate interest: product improvement, security, fraud prevention.
  • Consent: marketing communications, and measuring the effectiveness of our advertising using your device's advertising identifier (you can withdraw consent at any time).

5. Data Sharing

We never sell your personal data. Your health and fitness data (weight, body measurements, body composition, injuries, the content of your workouts) is never shared with an advertising partner. We may share data with:

  • Service providers: cloud hosting, email delivery, AI-generated workouts (Anthropic), subscription and in-app purchase management (RevenueCat, Apple, Google), error monitoring (Sentry) and anonymized audience measurement (PostHog) — only to the extent necessary to provide the service.
  • Advertising partner (Meta): to measure which ads bring in new users, the app sends Meta the install, app opens, completed sign-ups, and purchases, trials and subscriptions, together with your device's advertising identifier. On iOS, this identifier is only shared if you allow it through Apple's tracking prompt; on Android, you can reset or disable it in your device settings.
  • Your friends on Muskl: if you use the Friends feature (optional, for users aged 15 and over), the people you have accepted as friends see your first name, your username, your profile photo, a summary of your workouts (muscle groups, duration, volume), your personal records and your position in your friend group's weekly leaderboard. They never see your body weight, measurements, photos or the details of your workouts. Anyone who opens your invite link sees your first name and photo. Sharing stops as soon as you remove a friend or delete your account; you can also turn off username search and friend notifications.
  • Legal obligations: if required by law or a competent authority.

6. Apple Health and Health Connect

If you turn on this setting in the app, off by default, Muskl can save your completed workouts to Apple Health (iOS) or Health Connect (Android).

  • What gets written: the workout's duration, its type (strength training) and, if the corresponding setting is on, an estimate of calories burned. You can turn off this calorie estimate independently of saving to Apple Health or Health Connect.
  • No reading: Muskl does not read any health data from your device, not your weight, your sleep, your heart rate, or your steps. The access requested is write-only.
  • Data that stays on your phone: it is never sent to our servers or to any third party. Apple Health and Health Connect are local storage on your own device.
  • Removing access: on iOS, go to Settings, then Health, then Apps; on Android, open the Health Connect app. Turning off this setting in Muskl stops future writes, but does not delete data already written.

7. Data Retention

We retain your personal data as long as your account is active. If you delete your account, we will erase your data within 30 days, unless a longer retention period is required by law.

8. Your Rights

Under the GDPR, you have the following rights:

  • Access: obtain a copy of your personal data.
  • Rectification: correct inaccurate data.
  • Erasure: request deletion of your data.
  • Portability: receive your data in a structured format.
  • Objection: object to the processing of your data.
  • Restriction: request restriction of processing.

To exercise your rights, contact us at [email protected]. We will respond within 30 days.

9. Cookies

Our website uses essential cookies required for the service to function. We also use analytics cookies to understand how you use our site. You can manage your cookie preferences in your browser settings.

10. Children's Privacy

Muskl is not intended for children under 16 years of age. We do not knowingly collect personal data from minors. If you are a parent and believe your child has provided us with data, contact us so we can delete it.

11. Security

We implement appropriate technical and organizational measures to protect your data, including encryption in transit and at rest, strict access controls, and regular security audits.

12. Changes to This Policy

We may update this privacy policy. If we make material changes, we will notify you by email or through the app. The last updated date is shown at the top of this page.

13. Contact

For any questions about this privacy policy:

MSL Innov SAS
5 rue des boutons d'or
81380 Lescure-d'Albigeois, France
[email protected]