Fitbit has released a new watch face for all Fitbit Versa and Fitbit Ionic that makes it easier to track your estimated blood oxygen saturation (SpO2).
The SpO2 Signature clock face is available to download now through the Fitbit app, and lets you easily switch between views of oxygen saturation, daily activity goal, heart rate, step count and floors climbed.
- We've reviewed and rated all the best Fitbits
- For more variety, check out our full guide to the best fitness trackers
- On a budget? We've also ranked the best cheap fitness trackers
Why SpO2 matters
As Fitbit explained in a blog post announcing the new watch face, oxygen saturation while you're awake is generally between 95% and 100%. It tends to be a little lower at night, but typically remains above 90%.
Big changes in oxygen saturation, particularly overnight, might be a sign of a hidden health condition such as sleep apnea, in which your breathing stops and starts overnight. This can badly affect the quality of your sleep and leave you feeling very tired in the morning.
"With the SpO2 Signature clock face, your Fitbit smartwatch (Fitbit Ionic, Versa family, and Fitbit Sense) will track your average SpO2 levels while you’re sleeping," Fitbit said.
"To get started, once it is available, install the SpO2 clock face, then go to sleep wearing your smartwatch with the clock face, and within about an hour of waking up, you’ll be able to see your average SpO2 and range. Plus, you can expect more SpO2 clock faces soon to come in 2020!"
The SpO2 sensors in watches like the Fitbit Versa and Ionic series aren't as accurate as those used in hospitals, and aren't intended for use as medical devices, but can be a useful indicator that you should consider speaking to your doctor.
- Check out our roundup of the best running watches for every budget
Sign up to receive daily breaking news, reviews, opinion, analysis, deals and more from the world of tech.
Cat is the editor of TechRadar's sister site Advnture. She’s a UK Athletics qualified run leader, and in her spare time enjoys nothing more than lacing up her shoes and hitting the roads and trails (the muddier, the better)