Sleep is one of my most favourite and precious things and one of the benefits of being child-free is that it’s a commodity I can have plenty of - although never enough, obviously. Tracking sleep has been endlessly fascinating to me for a good while now, from those apps that suggested you pop your phone under your pillow to see how it’s going, to the first tracking introduced by Apple on the watch.

In watchOS 9, new features have been introduced that let you really dig into the details. Previously, the available analysis each morning would tell you how long you were asleep and when you were awake during the night. Useful, but there’s so much more to be gleaned.

The official Apple release points to these specific updates:

Sleep stage tracking using data from the accelerometer and heart rate sensor to detect time spent in REM, Core and Deep Sleep, as well as time spent awake

Comparisons chart provides a view of heart rate and respiratory rate alongside time asleep in the Health app on iPhone

Those four new modes really help you get an idea of how your night has gone, with some guidance about what to expect (eg. deep sleep is far less than anything else and usually in the first half of the night). Different colours represent each and there are two ways to view them: either you can go for the week view that lets you see how each day quite literally stacks up next to each other, or you can go for the daily deep dive that shows exactly when you hit each zone and how often you travelled between them.

It’s brilliant and enlightening and scary and man, I need more sleep.