The Fitbit Charge 4 is one of the best Fitbits around (and one of the best fitness trackers more broadly), and will soon get even better with a new app that will allow you to check your blood oxygen saturation (SpO2) right on your wrist any time you want, without having to grab your phone and open the Fitbit app.
We've known this feature was in the works since mid-February, when the company also announced that it was allowing owners of the Charge 4, Inspire 2 and Versa 3 to see trends from the previous week on their Fitbit Health Metrics Dashboard.
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At the time we weren't sure when the SpO2 app would begin arriving on the Charge 4, but as 9to5Google (opens in new tab) has spotted, a new firmware version is now rolling out that will finally give Charge 4 owners the extra tool.
The release notes for Update 1.100.34 (opens in new tab) state that "Your Fitbit device can now estimate your blood oxygen saturation (SpO2) while you sleep". In the morning, you'll be able to view this estimate by swiping up on the watch face to reveal a new SpO2 tile.
It's important to note that the Charge 4 isn't a medical advice, and night time SpO2 readings from the device can't be used to diagnose diseases like coronavirus. However, if your oxygen levels drop particularly low during the night, it could be a good starting point for a conversation with your doctor in case you're suffering from sleep apnea (a condition that causes you to stop breathing briefly overnight).
How to get the update
Fitbit advises that firmware updates aren't released based on region or location, and can roll out anywhere. The company doesn't recommend trying to force an update by performing a factory reset because you'll lose all data stored on your Charge 4, and may not receive the update anyway.
Instead, just be patient and keep an eye out for an update banner in the Fitbit app on your phone, then tap it to download and install the new firmware on your watch.
The Charge 4 is already one of the best Fitbits you can buy, thanks to its slim design, impressive fitness tracking features (including on-board GPS) and low price. This new update makes it even more appealing, so if you've been considering picking up a cheap fitness tracker, it's definitely one to put on your shortlist.
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