Privacy Policy

1. Who we are and what this covers

This policy explains what MacerFitness collects about you, what we do with it, who else sees it, how long we keep it, and what you can do about any of that. It covers the website, the web app and the iPhone and Android apps.

MacerFitness is the data controller for the personal data described here. We operate from London, United Kingdom, so this policy is written to comply with the UK GDPR and the Data Protection Act 2018, and with the EU GDPR where it applies to you. England and Wales law governs it.

Company details are being finalised and will be added here. The business is in the process of incorporating as MacerFitness Ltd, with a registered office at 71-75 Shelton Street, Covent Garden, London WC2H 9JQ. Once that completes we will publish the registered company number and our registration number with the UK Information Commissioner’s Office in this section.

For anything about your data, email contact@macerfitness.com.

2. The short version

• Your training and nutrition data is health data, and we treat it that way.
• We do not sell your data. The app and the website carry no advertising and no analytics or tracking product.
• To build and adapt your plan we send your body stats, goals and preferences to OpenAI. No name, email or account identifier goes with the request, so OpenAI cannot tie it to you.
• Photos you submit for a body fat estimate, and photos of meals, are sent for processing and are not stored by us. The photo is gone once we have the number, and the number is all we keep. The one exception is your choice: if you tick "Save my photos to my timeline", or add photos to your body timeline, we keep those photos privately for you until you delete them.
• You can download everything we hold and delete your account yourself, from inside the app, without contacting anyone.

3. What we collect

• Account data. Your email address and a secure hash of your password, or the Google, Apple or Microsoft account you signed in with. Plus two-factor authentication settings if you turn them on, and the invite code you redeemed.
• Profile data. Your first name and username, date of birth, gender, height, starting weight, body fat percentage, activity level, and your preferred units.
• Pregnancy status. If you tell us you are pregnant, we store that and your estimated due date. We ask because it changes what the app does: nutrition is held at maintenance instead of a deficit, and training is capped to pregnancy-appropriate intensity and movements. You never have to answer. If you choose a daily calorie target below your estimated maintenance while pregnant, we ask you to confirm first and keep a record of that choice: the target, the amount we recommended and when.
• Injuries and areas to work around. If you tick an area (lower back, knees or shoulders) or add a note about what to avoid, we store it so your plan can leave out the exercises that load it. It is optional, you can clear it in Settings at any time, and the note is sent to our plan generator as a description of movements to avoid. We don't give medical advice.
• Training and goal data. Your goal and target, experience level, how many days a week you train, the equipment you can get to, your dietary rules and any foods you have excluded.
• What you log. Every session you record, with its sets, reps, loads, rest times, how hard it felt, why you skipped it if you did, and any notes you write against a session or an exercise. Your body weight, steps and water. Every meal you log, including the text you typed and the calories and macros worked out from it.
• What we generate for you. Your training plan, your calorie and macro targets, body fat estimates, streaks, points and badges.
• Photos. Covered in section 6. We only keep the ones you save to your body timeline.
• Billing data. Whether you have a subscription, which one, and the reference numbers that identify it at Stripe or at the App Store or Google Play. Card numbers go to the payment processor and never reach us.
• Notification data. Push tokens for the browsers and devices you turned notifications on for, your timezone and preferred send time, and a record of which notifications went out.
• Bug reports. If you file one, we get your description, the screen you were on, your app version and operating system, and a screenshot of the page if you leave that box ticked. A screenshot of the app will usually show your own training or nutrition data, so untick it if you would rather it did not.
• Wrong-numbers reports. If you report that the calories or macros on a food look wrong, we keep the item as shown, any text you typed to get it, the figures you say are right and an optional note. We check it against our food list and, when the list does not know the food, with one web search that sends only the food's name, and we may use your report to improve the numbers for everyone. Photos are never attached.
• Waitlist data. The email address you gave us if you joined the waitlist before signing up.
• Technical data. Server logs from our hosting and database providers, which include IP addresses and browser information, plus rate-limit counters that stop the service being overloaded.
• Crash and error reports. When the app fails, we receive a report describing the failure: the error message, where in our code it happened, and what kind of browser or device you were using. Your identity is taken out of these reports before they are sent, and so is the content of anything you had typed or logged.

4. Health data and your consent

Most of what this app holds is data concerning your health under UK GDPR Article 9. Your weight, body fat, measurements, sleep, stress, what you eat, what you lift and whether you are pregnant all fall into that category, which carries stronger protection than ordinary personal data.

The condition we rely on to process it is your explicit consent under Article 9(2)(a). You give it by choosing to provide this information, and you can withdraw it at any time by removing the data or deleting your account, both of which you can do yourself from settings. Withdrawing does not affect anything we did with the data before you withdrew.

Alongside that, the legal grounds we rely on under Article 6 are:

• Performance of a contract for almost everything: running your account, building and adapting your plan, tracking your progress and handling billing. This processing is the service you signed up for.
• Consent for optional extras such as push notifications and email nudges, which you turn on and can turn off in settings.
• Legitimate interests for keeping the service secure and available, stopping abuse, and fixing the bugs you report to us. You can object to this processing at any time.
• Legal obligation for the anonymised transaction record described in section 10.

5. How your plan is generated

Your training plan, your calorie and macro targets, your meal suggestions, the coaching adjustments and the body fat estimates are all produced by automated systems, without a human reviewing them first. To produce them we send the relevant information to OpenAI, which runs the language and vision models behind those features.

What goes to OpenAI for a plan: your gender, date of birth, height, weight, body fat percentage, activity level, pregnancy status and due date if you gave one, your goal and target, your training preferences, your equipment and your dietary rules. Left out of the request: your email address and your account identifier. We send no end-user identifier with these calls, so OpenAI has nothing it could use to recognise you across requests.

Under OpenAI’s API terms, content sent through the API is not used to train their models. OpenAI may hold API requests for a limited period for abuse monitoring before deleting them.

You stay in control of the output. You can edit your calorie target for any week, build a plan entirely by hand instead of having one generated, regenerate a plan, swap or skip sessions, and ignore any of it. If you want a person to look at something the app produced for you, email contact@macerfitness.com and we will.

Nothing the app produces is medical advice, and it is not a medical device. Speak to a doctor before changing how you train or eat, especially if you are pregnant or have a health condition.

6. Photos and voice

Body fat estimate photos. If you use this feature, the photos you submit go straight to OpenAI’s vision model and come back as a number. They are not written to our database, not put in any storage bucket, and not kept on our servers in any form. What we store is the estimate, the range around it, a confidence figure and the date.

Photos you choose to save. The body fat estimate has a “Save my photos to my timeline” tick box, unticked unless you tick it, and you can add photos to your body timeline yourself, including older ones. Those photos are kept in private storage that only our server can reach, and you see them through links that stop working after an hour. Nobody else can see them. Once you have saved photos, a new body fat estimate also sends your last saved set to OpenAI with the new photos, so it can judge the change between them; as with every estimate, no name, email or account identifier goes with them. Delete any set from its timeline card and it is gone from storage straight away. They are included in your data export and deleted with your account.

Meal photos. The same applies when you photograph a meal to log it. The photo is used to work out what is on the plate and is then gone. The food entry is saved and the image is not.

Voice input. On the mobile app you can describe a meal out loud instead of typing it. Your phone does the transcription using its own speech service, which is Apple’s on iPhone and Google’s on Android, and that service may send the audio to Apple or Google to process it under their privacy policies. The audio never reaches us. We only receive the text it produces, which then gets treated like anything else you type.

7. Who else sees your data

We share data with the companies that run the product, and only as far as running it requires. Each of them acts on our instructions under its data processing terms, except where noted.

• Supabase. Our database, sign-in system and file storage. Holds everything in section 3 that is stored at all.
• Vercel. Hosts the website and runs the application code. Your data passes through Vercel every time you use the app.
• Cloudflare. Runs the bot check on the sign-in and waitlist forms. It sees your IP address and details about your browser so it can tell a person from a script, and it sends us back a pass or fail.
• OpenAI. Generates plans, targets, meal suggestions and photo estimates, as described in sections 5 and 6.
• Stripe. Takes payments on the web and holds your billing details. Stripe is its own controller for parts of that.
• Apple and Google. Take payments for subscriptions bought inside the mobile apps, as merchant of record and as their own controllers. They also run the notification services that deliver push messages to your device, and the speech services described in section 6.
• RevenueCat. Manages in-app subscriptions across the two stores and tells us what you are entitled to.
• Resend. Delivers our email, including sign-in links, invites, notification emails, account deletion notices and your data export when you ask for it by email.
• Expo. Relays push notifications from us to Apple and Google for the mobile apps. Expo sees your push token and the content of the notification.
• Sentry. Receives the crash and error reports described in section 3, so that we find out when the app breaks instead of waiting for someone to tell us.
• Open Food Facts. When you log a branded food, our server looks the product up in this open food database. Only the product name is sent. Your identity and your IP address are not.
• YouTube. If you add a YouTube link as the demo for a custom exercise, the video plays in an embedded frame from YouTube’s privacy-enhanced domain. Google receives your IP address when that frame loads. Nothing else on the site loads from YouTube.
• jsDelivr. A public content delivery network that serves the exercise animations in workout screens. Because your browser loads those images directly, jsDelivr receives your IP address and browser information, the way any website’s image host does.

Your meal partner. If you pair with another MacerFitness user, they see your first name and the food you log from the day you pair: each meal’s name, its items, calories and macros. Your weight, targets, workouts and pregnancy status stay private. You choose what they may do, and change it any time in Settings: view your meals, copy them, send meals to your saved meals, and add a meal straight onto your day (off unless you turn it on). You can also share your past meals (off by default), leave out whole meals such as breakfast, keep a single entry private, or pause sharing without unpairing. When they send you a meal or add one to your day we can notify you on the channels you already use for reminders. Pairing only happens when one of you creates a code and the other enters it, and either of you can unpair at any time in Settings. A meal you send to your partner, or one they copy from your day, becomes part of their own records and stays with them if you unpair or delete your account.

We may also disclose data if the law requires it, or to protect the rights, safety or security of MacerFitness, our users or others. We do not sell your personal data to anyone, and we do not share it for advertising.

8. Where your data is held

Your database records, including your account, your plan and everything you log, are stored in Ireland, inside the European Economic Area. Transfers from the UK to the EEA are covered by the UK’s adequacy regulations, so no extra safeguard is needed for them.

The application code that reads and writes those records also runs in Ireland. Vercel is a United States company, so its staff can reach that environment from the United States. OpenAI, Stripe, Resend, Cloudflare, Expo, RevenueCat, Apple and Google process data in the United States as well. For those transfers we rely on the standard contractual clauses with the UK International Data Transfer Addendum, which form part of each provider’s data processing terms.

Crash and error reports are stored by Sentry in Frankfurt, inside the European Economic Area. Sentry is a United States company whose staff can reach that data in order to run the service, and the details of our own account with them sit on their United States systems. Those parts are covered by the same standard contractual clauses and UK addendum.

9. Cookies and tracking

We use a small number of first-party cookies and nothing else. We run no analytics product and no advertising network, and the site loads no tracker.

The crash reporting described in section 3 does run on every page, so that a failure reaches us wherever it happens. It sets no cookies and it does not build a profile of you.

• Session cookies from our sign-in system, which keep you signed in and are required for the app to work.
• Preference cookies that remember your theme, accent colour and background settings so the page renders correctly before the app loads.

Two other services can store something in your browser. The bot check on the sign-in and waitlist forms comes from Cloudflare, which may keep a short-lived value to tell people from scripts and uses it for nothing else. A YouTube demo on a custom exercise loads from YouTube’s privacy-enhanced domain, which stores nothing about you until you press play.

Because nothing here is used for advertising or measurement, we do not show a cookie banner. If that ever changes we will ask for your consent before setting anything new.

10. How long we keep things

• While your account is open. We keep your data so your plan, your history and your streaks keep working.
• After you ask us to delete your account. Your billing is cancelled straight away and you are signed out everywhere. 30 days later everything is permanently erased and we email you to confirm. The window is there so a mistaken tap does not destroy months of training history. You can stop the deletion at any point inside it by signing in and choosing Keep my account.
• Transaction records. UK company law requires us to keep records of payments for 6 years. When we erase your account we first copy the non-personal parts of your payment history into a separate record: which product, which billing period, the status, when it happened, and the reference numbers our payment providers use. Your name, email, account identifier and everything else are left out, and that record has no link back to you. UK GDPR Article 17(3)(b) allows this as an exception to erasure where the law requires records to be kept.
• Photos and voice. Not kept, as described in section 6, except photos you save to your body timeline, which are kept until you delete them or your account.
• Technical logs. Server logs are kept by our hosting and database providers for their standard retention periods and are used for diagnosing faults and preventing abuse.

11. Getting a copy of your data, and deleting your account

Both of these are built into the app. You do not need to email us and we do not need to approve anything.

Download your data. On the web, go to Settings, open the Profile tab, and choose Download under Your data. You get a single JSON file with your profile, plans, workout history, food logs, preferences and account details. On the mobile app, Settings has the same option and sends the file to your account email address as an attachment.

Delete your account. The same section has Delete my account on both platforms. You type a short confirmation word, and the deletion is scheduled as described in section 10. There is also a public page at macerfitness.com/account-deletion explaining the steps if you cannot sign in.

One thing that catches people out: if you subscribed through the App Store or Google Play, deleting your account here does not cancel that subscription. Cancel it in your store settings as well, or you will keep being charged by the store.

12. Your rights

Under the UK GDPR, and the EU GDPR where it applies to you, you have the right to:

• Access a copy of the personal data we hold about you. The in-app download in section 11 gives you this immediately.
• Portability. The same download is structured JSON, so you can take it elsewhere.
• Rectification of anything inaccurate. Most of it you can edit yourself in settings.
• Erasure of your account and your data, which you can do yourself from inside the app.
• Restriction of processing, and to object to processing we base on legitimate interests.
• Withdraw consent at any time for anything we do on the basis of consent, including your health data and your notification settings.
• Not be subject to purely automated decisions that significantly affect you. Section 5 explains how plan generation works, how to change or replace what it produces, and how to ask a person to look at it.

For anything the app does not do for you, email contact@macerfitness.com from the address on your account. We respond within one month, free of charge.

If you are unhappy with how we have handled your data, you can complain to the UK Information Commissioner’s Office at ico.org.uk/make-a-complaint, by calling 0303 123 1113, or by writing to Information Commissioner’s Office, Wycliffe House, Water Lane, Wilmslow, Cheshire SK9 5AF. If you are in the EU you can complain to your local supervisory authority instead. We would rather you came to us first so we can put it right.

13. How we protect your data

• Everything is encrypted in transit, and the database is encrypted at rest by our hosting provider.
• Row-level security in the database means your credentials can only reach your own rows, enforced by the database itself rather than by application code.
• You can turn on two-factor authentication, and it is required for administrative access.
• Requests are rate limited per account so the service cannot be flooded or run up as a bill by someone else.
• We minimise what exists to protect. Voice recordings are never stored, photos are stored only when you save them to your body timeline, and no identifier is sent with the requests that generate your plan.

No system is perfectly secure. If a breach affects your data and puts you at risk, we will tell you and the ICO within the deadlines the law sets.

14. Age

MacerFitness is for adults. You need to be 18 or over to use it, and we do not knowingly collect data from anyone younger. If you believe someone under 18 has given us data, email contact@macerfitness.com and we will delete it.

15. Changes to this policy

We update this policy as the product changes. If a change materially affects you we will tell you by email or in the app before it takes effect. The date at the top shows when it was last revised.

16. Contact

Questions, requests or complaints about your data go to contact@macerfitness.com. See also our Terms of Service and the account deletion page.