Fitbit FB424BKYW-FRCJK Inspire 3 Fitness Tracker with Heart Rate Monitor Sleep Tracking Long Battery LifeProduct Highlights Monitor your heart rate 24 7 to understand which zone you are in during exercise: fat burn, cardio, or peak. You can check how much strain you are under. By pushing yourself within a reasonable range, you can expect benefits for your heart health. The more effort you put into the active heart rate zone, the higher your evaluation. The active heart rate zone feature records the time spent in your target heart rate zone. You can earn