Privacy policy

Last updated: 15 September 2026

Zentalog is an app to log and track your workouts. Here we explain, with no small print, what data we keep, what for, who we share it with and how you can take it with you or delete it. The conditions of the service are in the terms of use.

1. Who is responsible

Gextiona Interproducción, S.L. (tax ID B87967592), Avda. de las Provincias 36, posterior, oficina C, 28941 Fuenlabrada (Madrid, Spain), registered in the Madrid Companies Register, volume 3820, folio 60, sheet M-659211. For anything about your data: info@gextiona.art.

2. What data we keep

• Your account: name, email address, password (we only store an encrypted hash, never the password itself), @username, language, profile photo or icon, whether you want to appear in search, who recommended the app to you if you joined through an invitation and, if your account was created by your parent or guardian, who they are.
• Your personal details: your date of birth, which is required, and, only if you choose to give them, your country, gender, training experience and main goal.
• Your training: routines, workouts, sets (weight, reps, reps in reserve), cardio blocks (time, distance, incline), how you felt, notes and machine settings, favourite exercises, training types and group workouts.
• Health and body data, only if you enter it: weight, height, body measurements, body fat percentage, heart rate, calories, steps and daily activity, and the figure (male or female) you want to see on the muscle map.
• Your city: if you choose one, to show you the weather in «Today's plan». We do not use GPS or your exact location.
• Social: friendships, invitations, your relationship with your coach and the changes you make to the routines they give you.
• Payment: your plan, its dates and status, any coupons you use, your Stripe customer ID and the record that you asked for the subscription to start when you paid, and any free months you earn by recommending the app (for whom and when). We never see or store your card details: Stripe receives them directly.
• Your acceptances: which version of the terms and of this policy you accepted, and when.
• Technical and security data: sign-up date and last access, sign-in and sign-out log (with IP address), the devices where your session is remembered (browser type) and failed password attempts.

3. What we use it for and on what legal basis

• Providing the service (performance of the contract you accept when you sign up): your account, workouts and statistics, shared plans, your coach, your friends and the emails that are part of the service (email verification, password recovery, billing notices and invoices).
• Checking your age with your date of birth (legal obligation: in Spain you must be 14 to give consent yourself) and adapting training suggestions to your age (contract).
• Adapting suggestions to your experience and goal, if you tell us (contract). They are optional: the app works the same without them.
• Your health data (your explicit consent, given when you accept the terms and this policy): you enter it, it is optional and it is only used to show you your progress. You can withdraw consent at any time by deleting that data or your account.
• Internal service statistics (legitimate interest in knowing how the app is used in order to improve it): how many people use it and how many are active, by age band, country or gender. Always in aggregate, without names and without drawing conclusions about any individual. If you do not want to be counted by country or gender, leave those fields blank; for any other objection, write to us.
• Charging and invoicing (contract and legal obligation).
• Keeping a record of what you accept (legal obligation: we must be able to prove your consent).
• Protecting accounts and preventing abuse (legitimate interest): the access log and the limit on password attempts.

Weight, set and progression suggestions are calculated automatically from what you log, but they have no legal effects and do not significantly affect you: they are guidance only and you decide.

There is no advertising, we do not sell your data, we do not send newsletters and we do not build advertising profiles. We do not use third-party analytics.

4. Who else can see your data

• Other Zentalog users, only what you decide: people searching by @username see your name and @username if «appear in search» is on; accepted friends also see your photo; your coach sees your workouts and progress only if you accept their invitation, and you can withdraw that permission at any time; in a group workout, the people training with you see the shared workout; the holder of a Couple or Family plan knows you are on their plan but does not see your workouts. Nobody else sees your date of birth, country, gender, experience or goal.
• The providers we need to operate, under data processing agreements: Hostinger (servers and email, in the European Union); Stripe Payments Europe, Ltd. (Ireland), which charges subscriptions and issues invoices; and Open-Meteo, which only receives the coordinates of the city you choose, with no personal data. Stripe may process data outside the European Union with the safeguards required by the GDPR (standard contractual clauses).
• Google Play or the App Store, if you install the app or pay through them: they process their own data under their own policies.
• Authorities, only when the law requires it.

5. How long we keep it

• For as long as you have an account.
• When you delete your account, your data is deleted immediately. Server backups are overwritten automatically within 14 days at most.
• Invoice data for anything you paid is kept for as long as the law requires (six years under the Spanish Commercial Code, plus whatever tax rules require), in Stripe and in our accounts.
• Your email and IP address are removed from the security and acceptance log when you delete your account.

6. Your rights

• Access and rectification: you see and change your data in the app itself, under Account and Account › Personal details.
• Portability: you download your sets, workouts, measurements, activity and notes as CSV from Account.
• Erasure: you delete your account and all your data from Account › Delete my account, or from this page.
• Objection, restriction and withdrawal of consent: write to us.

For any of them, write to info@gextiona.art from your account's email address. If you believe we have not handled your data properly, you can complain to the Spanish Data Protection Agency (www.aepd.es).

7. Minors

• From 14 you can create your own account and give consent yourself.
• Under 14, Zentalog can only be used with an account created by your parent or guardian from their Family plan. That person gives consent on your behalf when creating it, and can exercise your rights or ask us to delete it by writing to us. These accounts do not appear in search.
• If an account of a child under 14 is left with no one responsible for it (for example, because the adult deletes their own account), it is blocked until another responsible adult writes to us, or it is deleted.

8. Cookies and storage on your device

We only use what the app needs to work, with no third-party, analytics or advertising cookies:

• The session cookie, deleted when you close the browser.
• The «keep me signed in» cookie, if you tick it, which lasts 90 days from last use.
• The chosen language, which lasts one year.
• In focus mode, if you turn on the voice, that preference is stored on your own device.

9. Security

Everything travels encrypted (HTTPS). Passwords are stored as encrypted hashes. Photos are stored outside the website, redrawn on upload to strip their metadata (such as the phone's GPS location) and only seen by your accepted friends and your coach.

10. Changes

If we change anything important in this policy, we will tell you in the app or by email before it applies and ask you to accept it again.