You’re not the only one experiencing this — Heart Rate Zone alerts have become unreliable in recent versions of watchOS, particularly in watchOS 10.4 and 10.5, including the most recent builds compatible with Apple Watch Series 6. This issue affects runners using custom workouts with HR Zone goals, especially when combined with audio cues like AirPods.
Here’s a breakdown of the situation, and what may help:
⚠️
What’s Likely Going Wrong
- Bug in watchOS 10.4+: Many users have reported HR Zone alerts intermittently failing, even though they are clearly inside or outside the targeted zone. The issue seems to affect both haptics and audio feedback.
- AirPods interference: In some cases, HR alerts that should be spoken through AirPods stop working entirely, while still silently displaying on the watch screen (which you’d miss unless checking manually).
- HR sensor delays or misreads in newer software builds may also be playing a role.
✅
What’s Been Known to Help (Temporarily)
- Unpair and re-pair your Apple Watch: This often resolves persistent watchOS bugs affecting sensors, haptics, and audio routing.
- Hard reboot both devices: Restart both your iPhone and Apple Watch, not just sleep/revive. This sometimes resets background audio or fitness services.
- Reset workout calibration data:
- On iPhone, go to Watch app > Privacy > Reset Fitness Calibration Data.
- (Note: This deletes all prior motion/HR learning for GPS and fitness.)
- Turn off AirPods and test alerts directly from the watch speaker (to see if it’s an AirPods audio routing bug).
- Toggle Siri voice feedback settings:
- On Watch, go to Settings > Siri > Voice Feedback, set to “Always On.” Sometimes, this triggers correct routing of audio cues.
🛠️
Other Workarounds
- Use a standard Outdoor Run workout (not a custom one) and just monitor Zone 2 visually. This default mode sometimes triggers alerts even when custom workouts don’t.
- Switch from “Goal: Distance in Zone 2” to “Time in Zone 2”, if your workout type allows it. Some users found time-based zone targets trigger alerts more reliably.
- Remove headphones before starting the workout, then connect them once the run has started and the alerts are activated. Sounds odd, but some runners found it worked.
📲 Missing iPhone Workout Editor
You’re absolutely right — it’s baffling that in 2025, Apple still doesn’t allow custom workout creation/editing on the iPhone. This has been a long-standing frustration in the fitness community, especially since creating or managing workouts on a tiny screen mid-run is clunky and error-prone.
Submit feedback here (seriously, they do see these):
Feedback - Watch - Apple
🔧 If All Else Fails
- Try downgrading your use to a stock workout and manually monitor HR zones for now.
- Consider using a third-party app like WorkOutDoors or Zones, which offer more control and more reliable feedback.
- Keep an eye on watchOS 10.6 or 11 (expected at WWDC). Apple tends to fix these kinds of regression bugs quietly in point updates.
🧠 Summary
Your setup should work — and it did work — so the most likely explanation is a recent software regression. Until a fix is issued by Apple, you’re stuck with workarounds like re-pairing your watch, testing without AirPods, or using third-party fitness apps for zone-based training.
