Terms of use

The terms on which the Marie Rosin Health apps are provided. Short, because the important parts are short.

Last updated 23 September 2026.

Who provides these apps

The apps are provided by Marie Wellness OÜ, registry code 17603292, registered in Estonia at Tähe tn 129b, 50113 Tartu. Contact: apps@marie.ee. Using an app means accepting these terms.

What these apps are, and what they are not

They are training and measurement tools. They guide interval training, breathing and cold exposure, record what you did, and estimate things like heart-rate recovery and VO₂max from your own measurements.

They are not medical devices and they do not give medical advice. Nothing they show is a diagnosis, and no number in them is a clinical measurement. Consult a doctor before starting any new training programme, particularly one prescribing near-maximal effort, which is exactly what the 4×4 protocol does.

You train at your own risk, and you are responsible for stopping when your body says so rather than when an app does.

Your account

One account, one person. Keep your password to yourself; anything done with your account is treated as done by you.

Give a true date of birth. It is not a formality: every training zone is calculated from it, and a wrong one produces targets that are wrong in the direction of too hard.

You must be at least 16 to have an account.

Subscriptions and payment

Some features need a paid subscription. Subscriptions are bought and paid for through the App Store or Google Play, not from us directly. The price you are shown at the moment of purchase is the price that applies, in your own currency and including whatever tax applies where you are.

Subscriptions renew automatically until cancelled. You cancel in the App Store or Google Play account settings, not here and not in the app. That is how both stores work. Cancelling stops the next renewal; it does not shorten the period you have already paid for.

Refunds are handled by the store you bought from, under its own rules.

A lapsed subscription never deletes anything you measured. Your history, your export and your ability to delete your account all keep working. What stops is starting new sessions beyond the free allowance.

Fair use

Do not try to break into the service, resell access, or use the apps to give other people training advice as if it were your own service. Do not upload anything to your diary that is unlawful. That is the whole list.

Availability

We aim to keep the service running but do not promise it will never be unavailable. The apps are built so that a session works on the phone without a connection, and syncing catches up afterwards.

We may change or withdraw features. If a change removes something you paid for, you can cancel and ask the store for a refund of the unused part.

Your data

How we handle your data is described in the privacy policy, which forms part of these terms.

What you record is yours. We claim no ownership of your training data, and you can export it or delete it at any time.

Our content

The apps, their design, text, audio and graphics belong to us or our licensors, and you may use them only as part of using the apps normally. The training protocols themselves are published science and belong to nobody; the 4×4 protocol is described as the Norwegian 4×4 only where the app actually implements it.

Liability

We are liable for damage we cause intentionally or by gross negligence, and for harm to life, body or health, without limit. Beyond that, our liability is limited to what you have paid us in the twelve months before the event.

We are not liable for injury arising from training you chose to do, or for decisions you take on the basis of a number the app estimated.

Nothing here limits the rights you have as a consumer under Estonian or European Union law. Where these terms conflict with those rights, those rights win.

Ending this

You can stop at any time by deleting your account, in the app or on the deletion page. Deleting the account ends these terms and removes your data as the privacy policy describes.

We may suspend or close an account that is being used to attack the service or break the law, and will say why unless the law prevents us.

Changes to these terms

If we change these terms in a way that matters to you, we will tell you in the app and ask you to accept the new version. Continuing to use the apps after that means accepting it.

Law

Estonian law applies. If we cannot settle a dispute between us, the courts of Estonia decide it. As a consumer, you may also bring a claim where you live, or take the dispute to the Consumer Disputes Committee at the Consumer Protection and Technical Regulatory Authority (Tarbijavaidluste komisjon, www.ttja.ee).