A new update for the Charge 4 is rolling out, which will let users view blood oxygen saturation from the wrist.
The update – spotted by 9to5Google – is part of a large package of new Charge 4 features that we reported on last month, with Charge 4 users also able to see a week’s worth of the company’s health metrics without a Premium subscription.
The Charge 4 already tracks blood oxygen levels at night in the Estimated Oxygen Variation feature, which is part of the advanced sleep tracking offering in Fitbit Premium.
That graph will show evidence of drops in blood oxygen in comparison to your personal baseline during sleep, and is essentially sleep apnea detection. However, despite having an SpO2 sensor from launch, there’s been no way to quickly check blood oxygen levels from the wrist.
Now Charge 4 users can see their oxygen saturation as a percentage on the wrist by swiping up from the home screen.
That does somewhat undermine its usefulness for things like checking levels when at altitiude or perhaps when sick (although we would recommend using a medical grade SpO2 sensor in this instance). But blood oxygen during sleep is more reliable, and a useful tool in identifying some common sleep disorders.
The update 1.100.34 is rolling out now, so if you’re a Charge 4 owner look for the prompt to update in your Fitbit app.