Privacy policy
Last updated: October 2026
If you create an account or sign up for the 10K en la Sierra newsletter, you trust us with some data. Here's what we do with it, with no small print.
Who is responsible
10K en la Sierra is a personal, non-profit project, and its owner is the data controller. You can write to 10kenlasierra@michaelkoper.com.
What data we process
For the newsletter, your email address, your language and the date you gave your consent. With an account, also your name (if you give it), your encrypted password or, if you log in with Google, your Google ID, the races you save and your notification settings. We don't use tracking cookies or build profiles: the only cookie keeps you logged in.
What we use it for
To run your account (saving your races and showing them to you), to email you when registration opens for your races, and to send you a monthly newsletter with the upcoming 10 km races in the Sierra de Madrid. Nothing else: we never sell or share your data.
Visitor statistics
To count visits we use Fathom Analytics, which uses no cookies and collects no personal data.
Legal basis
For your account, the contract you accept when you create it (Art. 6(1)(b) GDPR). For the newsletter and the notifications, your consent (Art. 6(1)(a) GDPR), which you can withdraw at any time.
Who else sees it
Resend sends our emails (account confirmation, notifications and the newsletter) as our data processor and only uses your address to deliver them. If you log in with Google, Google identifies you under its own privacy policy. The site and its data live on a Hetzner server in Finland, inside the EU.
How long we keep it
Your account, for as long as you keep it; you can delete it at any time in its settings, and all its data goes with it. The newsletter, until you unsubscribe in your account or with the link in any email.
Your rights
You can access, correct or delete your data, object to or restrict its processing, or ask for a copy by writing to 10kenlasierra@michaelkoper.com. If you think we've mishandled your data, you can complain to the Spanish Data Protection Agency (www.aepd.es).