BERLIN—The Garmin Vivosmart 4 is a wearable fit for a vampire. Unlike most regular fitness trackers—which settle for tracking heart rate, activity levels, and sleep patterns—the Vivosmart 4 unveiled here at IFA takes it a step further by keeping an eye on your blood oxygen level.
Fortunately, there's no bleeding required on your part. The measurements come from the pulse oximeter, which measures your blood oxygen saturation as you go about your usual activities.
The Garmin Vivosmart 4 can see how much oxygen you have surging in your blood when you're huffing and puffing on a treadmill, and how little when you're sitting slack-jawed on the couch or lying in bed. These measurements give you the kind of information you typically only get from a medical professional or much more expensive fitness trackers.
Another new feature is Body Battery. This lets Vivosmart 4 keep track of your overall energy levels by measuring heart rate, oxygen saturation, sleep, and stress levels to tell you when it's a good time to work out. The term Body Battery sounds a little dystopian, but if you're wearing a fitness tracker you've already reconciled yourself to that.
In other regards, the Vivosmart 4 is the same as the Vivosmart 3. In terms of design you get a slim band with several color options, and a simple small monochrome display with a single capactive button to interact with it. The wearable also has all the other fitness-tracking functionality you'd expect, like the aforementioned heart rate monitoring and sleep tracking.
The small size and light weight makes the Vivosmart 4 easy to wear. I put it on my wrist and forgot it was even there. The screen does seem a little small to receive things like weather and notifications, but it's still an option if you want it.
The Vivosmart 4 will be available for $129 later this year.