The Apple Watch Series 5 is already making noise even if there is still no confirmation of a release date. This is all thanks to possible features that are set to make the Apple smartwatch another bestseller.

Among the most anticipated features are health functions such as the electrocardiogram (ECG) application, which used to be available only in U.S. markets, and a possible sleep tracking function. However, some are doubting that the Apple Watch Series 5 feature to track sleep would actually fly.

In a Forbes report, Mike Kisch, the CEO of FDA-registered sleep wearable Beddr, said that the wrist is not a good spot to have a sleep tracker.

“Tracker position matters. Throughout the night when your arm moves around but your body stays relatively still, tracking the movements of a sleeping person’s body can get tricky when the device is attached to your wrist. Gauging what position you are sleeping in is crucial - and also very difficult to do if your tracker is worn on the wrist," Kisch said.

The most practical reason why a sleep tracking function might not work is battery concerns. Given that the smartwatch would be worn the whole day, it would make sense to charge the device at night when the owner is asleep.

"Fitness trackers like the Apple Watch and Fitbit face very real battery limitations. Multi-purpose devices want to be everything to everyone and try to do too many things at once. The challenge of continuously tracking your various physiological responses limits the amount of battery power a tracker can devote to an overnight sampling rate," Kisch explained.

The Beddr CEO also added other reasons why the new Apple smartwatch might not be successful when it comes to sleep tracking functions. These include damaging the watch because of uncontrolled sleep movements or inaccurately monitoring important sleep factors like oxygen levels.

However, as the smartwatch is not geared towards becoming a clinical-grade instrument, it is best not to put all data it gathers to heart.

Apart from the anticipated health functions of the Apple Watch Series 5, other features such as a ceramic casing and a possible round-faced feature are also being considered for a speculated September 2019 launch.

Apple Watch
The Apple Watch Series 5 is rumored to have sleep tracking functions. Pictured: General view of the Apple Watch during the Apple Covent Garden re-opening and iPhone XR launch at Apple store, Covent Garden on October 26, 2018 in London, England. Stuart C. Wilson/Getty Images