Why three, and not one
Because devices are good at different things, and forcing one choice would waste what you own. The example that makes it obvious: someone who trusts their Oura ring for sleep, and their Apple Watch for everything else. That is a completely reasonable position. The ring is on all night, it measures sleep well, and it gives figures the Watch cannot. The Watch is on all day, sees every workout, and tracks activity the ring never will. Forced to choose one, you would lose something real either way. So the app does not force you.The three choices
Primary — your general-purpose source
Primary — your general-purpose source
The default the Workbench reads from: resting heart rate, HRV, heart rate, blood
oxygen, active calories — and Capacity and Sleep too, unless you override them
below.Usually: whatever you wear most of the day.Each device is listed by name, with a note on what it can and cannot give —
“Full”, or “No daytime HRV”. That note is worth reading; it is the difference
between choosing a device and choosing a device that can answer.
Capacity — what feeds the recovery calculation
Capacity — what feeds the recovery calculation
Capacity is built from overnight physiology: HRV, resting heart rate, and how
your body settled during the night.Usually: whatever you wear in bed. If that is a ring, choose the ring even
if your watch is your main device.
Sleep — what your sleep screen shows
Sleep — what your sleep screen shows
Which device’s version of last night you see: stages, score, efficiency, and how
long you took to fall asleep.Usually: the device you trust most at night. Oura if you have one.
Worked examples
The pattern: the ring wins the night, the watch wins the day.
Changing your mind
You can, any time. But do it deliberately.If you are unsure
Leave it alone. The defaults are sensible, and a wrong choice here is not damaging — it just means a figure comes from a device you would not have picked.Next, and important
What happens when several wearables arrive through one hub.