Privacy Policy

Last updated: October 2026

Overview

This Privacy Policy explains what personal data the 42Runs app ("the App", "we", "us") collects, why, and how it's handled. We built the App to help you train and race better — not to sell your data, and we don't show ads or share your data with advertisers.

Who We Are

42Runs is developed by 42Endurance (42endurance.com), based in the Netherlands. You can reach us at contact@42endurance.com for formal data-protection requests.

What We Collect

Account information: your email address, display name, sex, date of birth (for VO2max fitness categories), and (if you add one) a profile photo.

Choices from a race page: if you fill in your email address on one of our race pages (for example the Marathon Rotterdam page) to get your training plan choices ready in the App, we store that email address (as a one-way hash) together with the choices you made on the page (race, number of training days, optional goal time). We send you one email about it. When you create an account in the App with the same, verified email address, the App picks up these choices and starts the plan builder with them. We delete them once they are picked up, or after 60 days, whichever comes first.

Training data you enter: races you're planning, workouts you add manually, your goal times, and your unit preference.

Training data from intervals.icu: if you choose to connect your intervals.icu account, we read your activities (type, distance, duration, date) and wellness metrics (like Fitness/Fatigue/Form and VO2max) from intervals.icu, and we can push structured planned workouts to intervals.icu on your behalf so they sync to your watch. If you haven't already set sex and date of birth in the App, we may copy those from your intervals.icu profile (Garmin-sourced when you use Garmin there) so VO2max can be classified.

Your intervals.icu credentials: your intervals.icu Athlete ID and API key are stored securely and are only ever used by our backend (Cloud Functions) to talk to intervals.icu on your behalf — the App itself, and anyone who might access our database directly, cannot read your API key back out.

Workouts from Apple Health: if you connect your Apple Watch, the App reads your workouts from Apple Health on your iPhone (type, date, duration, distance, heart rate, and for detail screens the route, pace, cadence and laps). The route and the individual heart rate readings stay on your phone. If you have no intervals.icu connected, the App sends a summary of each workout (type, date, duration, distance, average and maximum heart rate, and how many seconds you spent at each heart rate) to our servers, so we can calculate your Training Load, Fitness, Fatigue and Form. You can remove a workout from 42Runs at any time (it then also leaves our servers), and disconnect Apple Watch in the App; neither deletes anything from Apple Health. We don't use Apple Health data for advertising, and we don't share it with anyone.

Training data from Suunto: if you choose to connect your Suunto account, we receive your completed workouts from Suunto (type, date and time, duration, distance, heart rate, laps, and the route and heart-rate data recorded on your watch), and daily recovery data from your nights, such as a sleep score, heart-rate variability and resting heart rate, when Suunto provides it. We also send your planned workouts to your Suunto account as SuuntoPlus Guides, so they appear on your watch.

Your Suunto connection: the access tokens that let us read your data are stored securely and are only used by our backend to talk to Suunto on your behalf. The app itself cannot read them back.

Training data from Polar: if you choose to connect your Polar account, we receive your completed exercises from Polar (type, date and time, duration, distance, heart rate, and the route and heart-rate data recorded on your watch), and, where Polar provides it, sleep and recovery data such as a nightly heart-rate average and heart-rate variability. We cannot send planned workouts to a Polar watch.

Your Polar connection: the access tokens that let us read your data are stored securely and are only used by our backend to talk to Polar on your behalf. The app itself cannot read them back.

Training data from Garmin: if you choose to connect your Garmin account, we receive your completed activities from Garmin Connect (type, date and time, duration, distance, heart rate, laps, the device model, and the route and heart-rate data recorded on your watch) and, where you allow it, daily recovery data such as sleep, heart-rate variability and resting heart rate. We also send your planned workouts to your Garmin Connect calendar so they appear on your watch. You choose which of these you allow when you connect, and you can change it at any time in Garmin Connect.

How we use your Garmin data: only to show you your own training and recovery, to personalise your plans, to calculate your Training Load, Fitness, Fatigue and Form, and to send your planned workouts to your watch. Garmin data is never sold, never used for advertising, and never shared with data brokers. It is not used to train, evaluate or improve any artificial-intelligence or machine-learning model, and no AI or data-processing service receives it. Where we show Garmin data, or something calculated from it, we name Garmin and your device as the source.

Your Garmin connection: the access tokens that let us read your data are stored securely and are only used by our backend to talk to Garmin on your behalf. The app itself cannot read them back.

We don't track your location with the app. Any distance or route information comes from activities you've already recorded on your watch and that reach 42Runs through intervals.icu, Suunto, Polar or Garmin, or that the iPhone app reads from Apple Health. A route that comes from intervals.icu, Suunto, Polar or Garmin is stored with that activity so we can show it to you; a route read from Apple Health stays on your phone.

If you share a completed run as an image (photo from your library or a map of the GPS route, with time, pace, and distance overlaid), that image is composed on your device and stays there until you send it yourself through the system share sheet. We don't upload the share image to 42Runs.

Why We Collect It

To provide the App's core features: showing your upcoming races, generating and personalising training plans, tracking your performance over time, and keeping your calendar in sync with your watch.

Who We Share It With

We do not sell your data, and we do not share it with advertisers or data brokers.

How Long We Keep It

We keep your data for as long as your account is active. If you delete your account, we delete your data from our systems, other than what we're required to retain by law.

You can disconnect Suunto, Polar or Garmin at any time in the app (Settings → Connect Your Watch). When you do, we stop receiving new data, delete the connection credentials and the copies of your Suunto, Polar or Garmin workouts that we keep for that connection, and, for Garmin, tell Garmin to remove the connection. Activities already stored in your 42Runs history stay in your account until you delete your account or ask us to delete them. You can also withdraw access from within your Suunto, Polar or Garmin account. You can see and export all of your data in the app (Athlete tab, Settings, Personal Data), correct it there or by contacting us, and delete your account, which deletes your data, including everything we received from Garmin.

Your Rights

Depending on where you live, you may have the right to access, correct, export, or delete your personal data, and to object to or restrict certain processing. You can update most of your data directly in the App (Athlete tab and Settings), disconnect intervals.icu at any time, or contact us at contact@42endurance.com for anything else, including deleting your account.

Cookies & Analytics

This website (42endurance.com) uses Google Analytics to understand how visitors use the site — which pages are popular and where visitors come from. If you arrive from a Google ad, we also use the Google Ads tag to measure whether you requested a plan by email or opened the app stores. This only runs if you accept it in the cookie banner; if you decline, no analytics or advertising cookies are set. You can change your choice at any time by clearing your browser's local storage for this site and reloading the page.

Children

The App isn't intended for children under 16, and we don't knowingly collect data from them.

Security

We rely on Firebase's security infrastructure (encrypted storage and transport, access-controlled databases) to protect your data. No system is 100% secure, but we take reasonable steps to keep your information safe.

Changes to This Policy

We may update this Privacy Policy from time to time. If we make material changes, we'll let you know in the App.

Contact

Questions about your data or this policy? Reach out at contact@42endurance.com.