Docs
Sleep.
Sleep decides what kind of day is possible. Kata reads it automatically if you wear WHOOP, and takes your word for it if you do not.
Read automatically
Wear WHOOP and every morning arrives complete: time in bed and time asleep, the stages (light, deep and REM), how often you woke, your recovery percentage, HRV, resting heart rate and blood oxygen, plus your sleep debt and how much you needed. Apple Health and Health Connect bring their nights in the same way. The coach folds it into the daily line ("recovery is at 78%, green light for intervals").
Naps count too
A nap is sleep. Wearable naps flow in on their own, and you can add one in a sentence ("napped 40 minutes after lunch"). Naps sit alongside the night so the day's real total is honest, not just the hours between lights-out and the alarm.
Waking in the night
Broken sleep reads differently from a clean night, so Kata keeps it. A wearable reports the times you woke; without one, tell the coach ("slept about 7 hours, woke twice") and it counts. The number of wakes rides along with duration into your trends and your coaching.
Without a wearable
Tell the coach: "slept about 7 hours, woke up once". Manual sleep counts fully: toward your day score, your trends and your coaching.
Bedtime goal
Set a lights-out goal in Settings, Phase and goals, and the evening routine holds you to it.
How sleep shapes the day
Recovery moves what the coach asks of you: a hard session on a green morning, an easy one after a rough night. That is the advantage of one place that knows everything.