About Sleep Analysis
May 12, 2026
⚠️ This feature is exclusively for sauna device-3 (SAWATCH-3).
On the Sleep Log details screen, “Sleep Analysis” is a section to look back on that night's sleep in detail using three indicators: Effective Sleep Time, Sleep Need, and Sleep Debt.
It helps you see not only "how much you slept," but also "whether it was enough for you" and "whether recent lack of sleep has accumulated," revealing insights that cannot be understood just by the length of your sleep.
This page explains the descriptions and how to read the three indicators displayed in the Sleep Analysis section.
1. About Each Indicator
- Effective Sleep Time
This is the time spent sleeping, excluding the time you were awake.
It can be used as an estimate of the time you actually slept, rather than the time you spent in bed. - Sleep Need
This is an estimate of the sleep duration that is considered to have been necessary for you on that day.
It is calculated based on your age and the trends in your past records.By comparing it with the Effective Sleep Time, you can check if your sleep for that day was sufficient.
Sleep Need is personalized once enough data is accumulated
While there are few records, a general guideline based on age will be displayed.Once about 7 days of sleep data are accumulated, it switches to a Sleep Need based on your own record trends. By continuing to log, it will become an even more accurate estimate.
- Sleep Debt
This is an estimate of how much your recent sleep deprivation has accumulated.
It is calculated based on the deficit relative to the Sleep Need over the last few days.💡 How to reduce Sleep Debt
Since Sleep Debt is calculated by accumulating the deficit over the last few days, it will gradually decrease by adjusting your sleep duration over several days. Please note that sleeping longer for just one night will not immediately reduce it to zero.
2. Looking Back with the Trend Graph
⚠️ Features such as tracking the trend of Sleep Debt are currently under development.