How it learns you.
Your history, not population norms. And it keeps score on itself.
One tap. One line.
Check in as often as you like. Write it the way you'd text a friend. Ceiling reads it, tags it, and adjusts tomorrow when it should: three or more drinks caps it at steady, feeling sick at easy.
A drink or two usually shows up as a small HRV dip. Tomorrow stands, but expect the morning numbers to read a little low.
An example.
What actually moves your next morning.
Your next-morning HRV after nights like these, against your other mornings. A pattern shows once there are three nights of a kind and the gap is more than 5%.
An example. Stress and eating poorly show up too, once they make a real difference.
It checks itself.
Every call is tracked. Did you do what the morning called for, and did you wake up recovered? If following the call doesn't leave you more recovered, the call is wrong, not you.
Woke up recovered when you did what the morning called for. 21 of the last 30 days.
When you went over or off plan. The other 9.
An example.
Measured against you.
Zones from your own threshold, measured in your own sessions. HRV, resting heart rate and sleep are read against your own normal, so you're only ever compared to you.
Not 220 minus your age.