How do I set the rest timer?
To set the rest timer for workouts performed from the Apple Watch, you'll have to edit the routine on your iOS device.
- Go to the Start Workout tab, tap the [...] button, and select "Edit Routine."
- Tap the [...] button next to the exercise and select "Auto Rest Timer."
- Activate the auto rest timer for that exercise by turning on the Enabled switch and selecting a time for your rest period.
NOTE: The Watch app handles the rest timer a little differently from the iOS app. Currently, the Watch app doesn't support the warm up rest timers for an exercise just yet.