Garmin CIRQA Hits 77% Deep Sleep Accuracy but Struggles with REM

A review of Garmin’s screenless CIRQA wearable found strong heart-rate tracking and solid deep-sleep performance.

Deep sleep showed 77% agreement, but REM sleep accuracy was notably weaker.

Cycling was tracked well, while interval training and weightlifting were less reliable.

Garmin says it plans algorithm updates to improve overall tracking accuracy.