(Pocket-lint) - If you were wondering how much charge you have left in your body battery each day, wonder no more. The Garmin Vivosmart 4 comes with a body battery energy monitor to tell you when you should be using up that extra energy on an activity, or whether you need to rest.
In addition, the new slim and sleek activity tracker has a wrist mounted Pulse Ox sensor to monitor your blood oxygen saturation when sleeping, to help you better understand your sleep patterns.
It also has an advanced sleep monitoring system that estimates light, deep and REM stages of sleep, along with movement in the night. The stats can then be studied to see if you need to change anything at bedtime.
The Vivosmart 4 has a heart rate sensor too, with the ability to detect abnormalities in rhythm and alert you. And there is all-day stress tracking with a new relax reminder feature that suggests you take breathing routine breaks when it detects high stress levels.
It connects to the Garmin Connect Mobile app for iOS and Android, and also receives general notifications from your phone, along with enabling music control from your wrist, weather reports and much more.
The Garmin Vivosmart 4 has up to seven days battery life and comes in several colours: berry with rose gold bezel, powder grey with silver bezel, azure blue with silver bezel, and black with slate bezel.
It is available to buy now, priced at £119.99.