Wearable Sleep Data: Which Metrics Are Reliable?
Wearable devices track sleep stages, breathing, movement, and recovery scores using sensors like accelerometers and pulse oximetry. This guide helps informed readers judge which metrics tend to match reality, which ones drift, and how to test them at home. You’ll learn what “reliable” means for sleep tracking, how to interpret common charts, what to cross-check with symptoms, and when to treat data as a clue rather than evidence.