How to run intervals on Apple Watch

There are three ways to run intervals on Apple Watch: build a custom workout in Apple's Workout app, send a ready-made workout into it from an iPhone app, or run it in an app that has its own Watch app. Here's how each one works on watchOS 26 and 27, and what it can't do.

1. Build a custom workout in Apple's Workout app

Custom workouts came with watchOS 9 and are free. On the Watch:

  1. Open the Workout app and turn the Digital Crown to Outdoor Run.
  2. Tap the Goals button, then Custom, then the Add button.
  3. Set a warmup by time, distance or open.
  4. Tap Add, choose Work or Recovery, and set it by time, distance or open. Repeat for every interval.
  5. Set a cooldown, name the workout and tap Create Workout.

You can add alerts for pace, heart rate zone, cadence or running power, and during the run the Up Next view shows what's coming.

Building it on iPhone

Since iOS 26 you can build the same workouts in the Fitness app on iPhone: open the Workout tab, choose Outdoor Run, then Goals, Custom and Add. The iPhone builder also has repeat blocks, so 6 × 800 m is one block instead of 12 steps, and a target for each step. It needs a paired Apple Watch on watchOS 26 or later (Series 6 or newer, SE 2nd generation or any Ultra), and the workout syncs to the Watch.

2. Send a workout from an iPhone app

Running apps can hand workouts to Apple's Workout app through Apple's WorkoutKit. Either you add it to the Watch from Apple's preview, or you let the app schedule workouts, which then show up in the Workout app with that app's icon. You run them with Apple's own screens and alerts.

The trade-off: inside Apple's Workout app, the other app can't talk to you, so its voice coaching stays behind, and Apple's targets for each step are pace, heart rate, cadence or power, with no target for effort. Fartlek works around the second part by putting the effort in each step's name, so a rep shows as "90% effort". In Fartlek, open a run from your training plan and tap Send to Apple Watch; when you finish it in the Workout app, it comes back to your plan as done.

3. Use an app's own Watch app

Apps such as Fartlek, Intervals Pro, Seconds and RUN interval also run intervals in their own Watch app, with their own screens and cues. That's how you keep an app's voice coaching on your wrist. If you want to leave your iPhone at home, check that the Watch app works on its own: some do, others need the phone nearby.

Which one to use

  • A one-off session, for free: build it in Apple's Workout app.
  • The runs of a training plan, on your wrist: send them from your plan app to the Workout app.
  • Voice coaching or effort targets: use the app's own Watch app, or run with your iPhone and its cues.

Tips

  • Distance reps rely on GPS. Between tall buildings or under trees, reps by time are more reliable.
  • Make a recovery open if you want to start the next rep yourself, and keep work steps by time or distance.
  • Start every session with an easy warm-up before the first hard rep.

Comparing apps? See interval running apps for iPhone, compared.