crazyRun: Interval Training
Running workouts & pace coach
Free
Write your workout as one line and the watch runs it: intervals, target paces and spoken cues. No account, no servers, no ads. Your data is yours.
crazyRun runs structured workouts on your Apple Watch. Write the session once and the watch does the rest: it tells you at every phase change, calls out your pace every kilometre and lets you run without looking at the screen.
WORKOUTS YOU WRITE AS ONE LINE
Instead of filling in forms, type the session:
10'[Warm-up]+5x(3'[Pace:4:30-4:45]+1'[Rest])+10'[Cool-down]
Ten minutes of warm-up, five three-minute reps at target pace with one minute of recovery, and ten minutes of cool-down. Repeats, phases, intervals by time or distance, target pace or heart rate, and a name for every segment. A plan that needs different settings? Add settings for that workout only (auto-pause, alerts, voice…). And if you prefer, there's a visual editor.
ALERTS THAT DON'T NAG
The watch judges your pace over a 30-second window and only tells you when you're really off target. On long segments it looks at the average: it tells you the pace you need to finish the segment within range. Heart-rate alerts too, by voice, on screen or with haptics.
RUN, BIKE AND HIKE
Three modes, each with its own physics. On the bike you see speed in km/h; running and walking, pace. A 45 km/h descent and a 2 km/h mountain climb are both recorded correctly. Every workout is saved to Health with the right type, its route and the distance crazyRun measures. In kilometres or miles.
BUILT FOR LONG OUTINGS
• Auto-pause that tells stopping from going slowly, using the pedometer as well as GPS. Set per mode.
• Power saving for multi-hour stages: with your wrist down the screen goes almost fully dark, but recording is never touched.
• Spoken cues with adjustable volume, and Digital Crown control.
WHAT IT MEASURES
Pace, distance, time, heart rate and zones, cadence, elevation, calories, estimated power, training load (TRIMP) and heart-rate recovery. Splits per kilometre, per phase and per interval, with each segment coloured by whether you hit the target. Charts, route map, personal records and race predictor.
AFTER THE WORKOUT
History, calendar, trends and side-by-side comparison. Export one workout or a period to GPX (with heart rate), TCX (with a lap for every rep), CSV or JSON. Backups you create and take with you by email, AirDrop, iCloud Drive or the Files app.
YOUR DATA IS YOURS
No account. No sign-up. No servers. No analytics. No ads. Your workouts stay on your iPhone, your watch and in Health. If you turn on sync, they go to YOUR iCloud, not to a server of ours.
IN 17 LANGUAGES
Arabic, Bengali, Catalan, Chinese (Simplified and Traditional), English, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Portuguese, Russian, Spanish and Thai.
REQUIREMENTS
iPhone with iOS 17 or later. The iPhone records any workout on its own, with its GPS. With an Apple Watch (watchOS 10 or later) you record it from your wrist.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
• Plans with a date and time: add [Date: 2026-10-22 9:00] to the text, or turn on Time in the editor. The reminder arrives at the plan's time.
• The plan list is sorted by date.
• Segments CSV: smoothed elevation with net and grade, grade-adjusted pace (GAP), per-kilometre splits and how far to trust the heart rate.
• Plan detail shows its time and the workout type in your language.
• Improvements and fixes.
The developer, Irene Juarez, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Irene Juarez
- Size
- 13.1 MB
- Category
- Sports
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Apple Vision
Requires visionOS 1.0 or later. - Apple Watch
Requires watchOS 10.0 or later.
- iPhone
- Location
- This app may use your location even when it isn’t open, which can decrease device battery life.
- Languages
English and 16 more
- English, Arabic, Bengali, Catalan, French, German, Hindi, Indonesian, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Thai, Traditional Chinese
- Age Rating
4+
- 4+
- Copyright
- © 2026 crazydev