iOS app · Running calculator & log
RunXYour Win Sprint
One race result. Every pace you need.
Equivalents
5K → Marathon
Training paces
5 zones
Data stays
On device
About the app
What RunX does
RunX — Your Win Sprint turns a single race result into a plan. Enter the time you ran on any distance and the app works out what that form is worth everywhere else, how fast your easy runs and intervals should be, and what the clock has to read at every kilometre of your next race.
Every projection uses the Riegel formula, and anything stretched far beyond the distance you actually ran is marked as optimistic. No account and no sign-up — results, goals and your runner profile stay on the device.
Pace zones
- Recovery
- Easy
- Threshold
- Interval
- Repetition
Feature list
What you get
Board
Pick a distance, type the finish time and get equivalent times for 5K, 10K, the half and the marathon — or any custom distance from 400 m — with a pace ruler that shows where each one sits.
Field
A seven-step class ladder built on 10K anchor times, with men's and women's scales, showing which class your form places you in and how far the next rung is.
Marks
A log of your results with surface, effort, elevation, conditions and notes. Open any mark to see its pace, its equivalents and how it compares with the run before it.
Zones
Five training paces built from your threshold, from recovery jogs to fast repetitions.
Season
A race goal with target time and date, the pace it requires, the gap between your current projection and the target, a progress curve and results per month.
Splits
A kilometre-by-kilometre (or mile) breakdown for the goal race: even, negative or positive split.
Gallery
App screens
Legal
Privacy policy
Last updated: 25 September 2026
No account, no sign-in
RunX — Your Win Sprint works without an account, without registration and without any sign-in. The app does not collect, transmit or sell personal information.
Your data stays on your device
The race results you enter, your goals, your runner profile, and the equivalent times, training paces and splits the app works out are calculated and stored only in the local storage of your device. They are never uploaded to any server.
No GPS, no Apple Health
The app does not use GPS, does not track your runs, and does not read or write Apple Health data. Every number comes from times you type in yourself.
Notifications
If you allow notifications, the app receives a notification token from Apple and registers it together with a random identifier created by the app itself on installation. That identifier is not your name, email or advertising identifier. It is used only to deliver notifications, and you can switch notifications off at any time in the iOS Settings.
No ads, no analytics, no tracking
There are no advertising SDKs, no third-party analytics and no tracking. The app does not use your location, contacts, camera, photo library or microphone.
Not medical advice
The app is a calculator and training log, not medical advice. Check with a professional before changing your training load.
Independent app
The app is independent and is not affiliated with, endorsed by or connected to any athletics federation, race organiser or brand.
Children
The app is not directed to children under 13.
Deleting the app
Deleting the app erases all results, goals and your profile permanently.
Changes and questions
If this policy changes, the updated version will be published on this page. Questions can be sent to vaclav@horakapp.space.
Get in touch
Contact us
Email: vaclav@horakapp.space