Oura Ring Sleep Tracker

Oura Ring is a sleep and activity tracker shaped like a titanium ring. First thing I noticed when my friend showed me hers is that it doesn't look like a piece of technology at all, it looks like a matte silver wedding band with a slightly thicker profile. Sensors on the inside measure heart rate, body temperature. Blood oxygen while you sleep, and the app translates that data into a readiness score each morning that tells you whether your body recovered enough for a hard workout or needs a rest day. I admire how the form factor solves the biggest problem with wrist-worn trackers, which is that most people do not want to sleep in a watch. At 6 grams, the ring is light enough that you forget it's there. Charging cradle is a small concave disc that the ring sits in upside down. A full charge lasts about 5 days, which is long enough that charging becomes a weekly habit rather than a daily chore. Temperature trend feature is the most interesting health signal because it can detect the onset of illness 2 or 3 days before symptoms appear. Several studies during the pandemic used Oura data to track early COVID indicators. Sleep staging is detailed, breaking the night into light, REM, and deep phases with timestamps.