Privacy Policy

Last Updated: February 19, 2026

EnduranceOS is a race nutrition planning tool for endurance athletes. Your privacy is a core value — your performance data belongs to you, not advertisers.

1. Data We Collect

DataWhenPurpose
Race inputsWhen you use the calculatorGenerate your fueling plan. Processed client-side; not stored unless you save a plan.
Email addressWhen you unlock or save a planDeliver saved plan links, PDFs, and optional race-week reminders.
Saved plansWhen you save a planStore your inputs and outputs so you can reload, edit, and share.
Weather dataWhen you select a locationFetch weather from Open-Meteo. We send only coordinates and date — no personal data.
FeedbackOptional, post-raceImprove our formulas. Linked to your plan, not your identity.
Hashed blog view identifierWhen you view a blog postPrevent duplicate or bot-heavy counting and maintain more accurate public read counters.
Forecast opt-inOptionalSend race-week weather and nutrition reminder emails.
Race directory dataNot user-providedPublicly available race details (names, dates, locations) aggregated from third-party APIs. No personal data is collected through race pages.

We use Vercel Analytics for anonymized, aggregate page view data (no cookies, no IP tracking, no fingerprinting).

2. How We Use Your Data

  • Plan generation: Your inputs create a personalized fueling blueprint. The calculator runs client-side in your browser.
  • Plan delivery: If you provide an email, we use it to send your saved plan link, PDF exports, and optional reminders.
  • Formula improvement: Post-race feedback is aggregated and stripped of identifying information. We never analyze individual feedback tied to your email.

3. Third-Party Services

ServiceWhat we shareWhy
SupabaseSaved plans, email, feedback, hashed blog view identifiersDatabase hosting
ResendEmail addressTransactional email delivery
Open-MeteoGPS coordinates, dateWeather data (no personal data sent)
VercelStandard web request dataApplication hosting
Vercel AnalyticsAnonymized page viewsUnderstand which pages are used (no cookies, no IP tracking)
RunSignUpNone (we read their public API)Source race details (dates, locations, registration status). Registration links may include an affiliate tracking parameter.
World TriathlonNone (we read their public API)Source international triathlon race details.

We do not share your data with advertisers, data brokers, insurance companies, employers, or any party not listed above.

4. Affiliate Links

Some links on race pages — specifically registration links to RunSignUp — include an affiliate tracking parameter. If you register for a race through one of these links, EnduranceOS may receive a small commission at no additional cost to you.

These links do not track your identity or browsing behavior on our site. The affiliate parameter is only included in the outbound URL to RunSignUp.

5. Data Retention

  • Saved plans and email: Retained until you request deletion. There is no automatic expiration.
  • Feedback: Retained indefinitely in aggregated form for formula improvement.
  • Hashed blog view identifiers: Retained for anti-abuse and read-counter accuracy.
  • Calculator inputs (unsaved): Never stored on our servers. Processed entirely in your browser.
  • Forecast opt-in: You can unsubscribe at any time.

6. Your Rights

  • Access your saved plan data via your plan link at any time.
  • Delete your email, saved plans, and all associated data by contacting us. We process deletion requests within 30 days.
  • Opt out of reminder emails at any time.
  • Export your plan as a PDF.

To exercise any of these rights, email hello@enduranceos.app.

7. Security

  • All data is transmitted over HTTPS.
  • Database access uses service-role keys restricted to server-side operations.
  • We do not store passwords (there are no user accounts).
  • Plan links use unique, unguessable identifiers.

8. Children

EnduranceOS is not directed at children under 16. We do not knowingly collect data from minors.

9. Changes to This Policy

If we make material changes, we will update the “Last Updated” date at the top of this page. Continued use of EnduranceOS after changes constitutes acceptance of the updated policy.

Questions? Contact hello@enduranceos.app