Numerous Apple Watch owners at MacRumors and Apple's own support forums are reporting that the device's heart rate sensor has been taking readings less consistently ever since Apple released a software update on Tuesday. By default, the smartwatch is supposed to take your heart rate every 10 minutes throughout the day. The frequency of heart rate measurements jumps dramatically during workouts so that the Watch can better track your exertion in real time.
But after installing Watch OS 1.0.1, users are noticing huge gaps of time where the Apple Watch fails to record any heart rate data. (You can check your heart rate history by opening the Health app in iOS.) Several Verge employees have seen similar behavior. Ever since the 1.0.1 update, the Apple Watch has been far more sporadic in when it decides to take a reading. Sometimes it behaves as intended, but there are very obvious gaps — some as long as an hour — where nothing is being saved at all. The Watch was never removed or turned off during the period reflected below:
The Apple Watch is designed to take heart rate measurements every 10 minutes.
Is Apple cutting down on the frequency of heart rate measurements to give the Apple Watch an even bigger battery boost? That's unlikely, since the company's website still mentions the "every 10 minutes" interval. The update's release notes also make no mention of adjustments or changes to how the heart rate sensor functions.
It's worth noting that the heart rate sensor still works just fine when manually accessed via its dedicated Glance and also during workouts, when it records HR data in the same way it has since launch. So this bug is really only one that the company's most diehard fitness users are likely to notice. But that's an important new market for Apple, and hopefully the company can resolve this by the time Watch OS 1.0.2 rolls around. We've reached out for more details. Remember that this is a new product for Apple, so if you're seeing this or other issues, you can help erase those bugs by reporting them here.