Health & Fitness TrackingThe Fitbit Air relies entirely on the newly redesigned Google Health App (available on both iOS and Android) to sync and display data. It features an optical heart rate sensor, skin temperature variations, and red/infrared sensors for blood oxygen tracking.24/7 Monitoring: Tracks resting heart rate, steps, and heart rate variability (HRV).Advanced Sleep Tracking: Monitors sleep duration, sleep stages (Deep, Light, REM), and calculates a daily Sleep Score.Cardio & Training Load: Measures "Cardio Load" to track daily cardiovascular strain and provides a Daily Readiness score.Automatic Exercise Detection: Automatically recognizes and records most workouts.Heart Health: FDA-certified background Afib detection to monitor irregular heart rhythms.