Your ring is a good coarse instrument and a bad fine one. For asleep-or-awake it matched the sleep lab at least 95 percent of the time. For the nightly stage breakdown you actually check, deep and REM minutes, the same devices dropped to 50 to 86 percent. No update fixes it: even trained human scorers agree only about 83 percent of the time. Sold a precise number that is not precise, people worry, and nearly 31 percent of trackers now score positive for orthosomnia risk. Use it sanely:
- Trust the coarse call: roughly when you slept and how long you were down
- Grade the weekly trend, not the nightly bar chart
- When your REM number is down and you feel fine, believe your body
I wear the ring. I also leave it in a drawer some nights, which is the most honest sleep advice I own.
