Stability (overnight data) measures two metrics: overnight resting heart rate (HR) and overnight heart rate variability (HRV), while you sleep wearing your Visible Band 2.0.
It uses a four-hour period that starts 30 minutes after you fall asleep. It looks at readings when you are still and ignores times when you are moving. Studies suggest the early hours of sleep are more sensitive to reflect recovery than the whole sleep period.
Why overnight instead of morning?
Overnight measurements are often more consistent because:
They're measured over a longer time period (4 hours vs. 1 minute).
Your body position is more stable during sleep.
Sleep provides a controlled environment: consistent posture, mental state and signal quality.
Morning measurements require more consistency (same position, same time after waking) which is not always easy.
Your overnight HRV may look different from your morning HRV. This is normal. The Stability algorithm accounts for these differences when working out how stable your HRV is compared to your recent baseline.
Using overnight data if you have difficulty sleeping
Using overnight data if you have difficulty sleeping
Sleep issues such as insomnia or disrupted sleep are common for people with complex chronic illness. Stability calculates your overnight measurements by averaging readings overnight when the band receives a good signal and ignores periods when you’re awake or moving.
If your sleep is heavily disrupted, we still recommend trying Stability in Overnight mode and seeing how it works for you.
If your Stability Scores feel like they match your experience, then Visible is likely gathering enough relevant data from your band overnight. If your scores don't match your experience, switching to morning readings may be the best option for you.
Any time you switch between overnight data and morning readings, you may need to build a new baseline. Visible will let you know.
To switch to morning readings:
Go to Profile → Stability in the app.
Choose Take a morning reading.
Then, when you wake for the day, take a short morning reading to get your Stability Score.
For more information on how to use morning readings, see Getting your Stability with Morning Check-in.