Utilize 24/7 heart rate to more accurately track calorie burn, resting heart rate & heart rate zones during workoutsTrack all-day activity, including steps, distance, hourly activity, active minutes and calories burnedAutomatically track sleep, plus due to the heart rate feature, get more insights into your light, deep & REM sleep stagesEnjoy up to 5 days of battery for daily progress without constant charging. Varies with use and other factors.Automatically and conveniently record workouts like walks, swimming & bike rides in a snap with SmartTrack