Garmin Vivosmart 4 sees your body as a battery to let you know when you're tired

Following on from the Garmin Vivosmart 3, Garmin has just announced the Vivosmart 4, a new fitness tracker which aims to stand out in part thanks to its wrist-based pulse ox2 sensor, which can measure your blood oxygen saturation levels.

While there are a number of reasons you might want to do that, Garmin highlights its usefulness for helping you understand your sleep quality by checking it at night.

Indeed, sleep tracking seems to be a major focus for the Garmin Vivosmart 4, as it can also monitor how much light, deep and REM sleep you get and how much you move during the night.

But that’s just one of the many health and fitness tools it offers. Another is Body Battery – a feature which estimates your body’s energy levels through a combination of sleep, activity, heart rate variability and stress levels.

It presents your energy level as a number, with higher being better, so you can see at a glance how rundown you are and whether you should rest.

Swim-proof and long-lasting

Those are the headline features, but there’s plenty more here, including a heart rate monitor, VO2 max, stress tracking and the ability to track walks, runs, yoga and strength training, among other things. 

The Vivosmart 4 is also swim-proof, so you can track your swims as well - although it lacks GPS for proper run tracking.

Plus there’s a relaxation breathing timer for when you’re stressed out, you can get and reply to notifications from your smartphone on its OLED screen, and the battery apparently last for up to 7 days.

If you like the sound of it, you’ll be able to buy the Vivosmart 4 for $129.99/£119.99/AU$199 in berry with a gold bezel, powder grey with a rose gold bezel, azure blue with a silver bezel, or black with a slate bezel.

It’s not available yet but should be soon – Garmin’s US site estimates 3-5 weeks, while its UK announcement places the launch sometime in the third quarter.

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