The Apple Watch 4 is a powerful health and fitness tracker. An important and surprising task is sleep tracking. Because you can do this with third-party apps, this feature is not offered by default. That could change soon.
According to "Workers Familiar", which Bloomberg introduced in an interview with Bloomberg, Apple has secretly been testing a sleep tracking feature for months and plans to add it to the Apple Watch by 2020.
It is not clear if this would be exclusive to the latest model (probably the Apple Watch 6) or whether it would be added as a software update. However, since most of the hardware should already be in place (eg, a heart rate sensor and an accelerometer), this could well be a feature that older Apple Watch models could get. Of course there is also the possibility of a sleep tracking feature on every Apple Watch is now just a rumor, so let's take it with a side salt. But it makes sense, as it's an obvious missing feature that would help Apple compete better with Fitbit, which has its own sleep-tracking feature.
This would not be the first time that Apple has been interested in monitoring sleep since the company had previously bought Beddit ̵
A battery operation?
As Bloomberg notes, the Apple Watch may have a disadvantage for sleep monitoring. Battery life can not compete with some fitness trackers, such as the Fitbit Versa, which lasts about 3-4 days between charges. The Apple Watch 4 for comparison is usually charged at night, which is inconvenient if you also want to carry it in bed.
It is possible that we have not yet seen the sleep tracking on the device. This means that the battery life is something else that Apple wants to tackle in the near future, but that's just speculation.
However, if Apple can provide better battery life and a sleep tracking feature for the Apple Watch 5 or 6, then this could be an important step to justify upgrading an older model.