Apple Watch Series 6: SpO2 tracking is still in its early stages


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  • Always-on display looks bright even after it’s timed-out
  • Measures blood oxygen levels automatically
  • Better battery life during runs

Don’t Like

  • SpO2 data is hard to interpret
  • Still requires daily charge with sleep tracking and always on display

The Apple Watch Series 6 feels like it has perfected many of the features I liked about its predecessor. It has a brighter always-on display, a more powerful processor, faster charging and two new colorful options to choose from. But the feature I was most excited to try out was its new sensor that measures oxygen saturation in the blood (aka SpO2) with the tap of a screen. As someone who panic-bought a pulse oximeter at the start of the coronavirus pandemic and still checks her levels at the first sign of a cough, the thought of having one strapped to my wrist at all times was enough to pique my interest.

But unlike the ECG feature on the Apple Watch, which has been tried, tested and cleared by the US Food and Drug Administration, along with the irregular heart rhythm notifications, SpO2 on the Apple Watch still seems to be in its early stages. Navigating all this new data can be daunting for anyone who’s not a medical professional. 

SpO2 leaves some unanswered questions

I bought an FDA-cleared pulse oximeter, the device doctors use to measure SpO2 on your fingertip, as a precaution when coronavirus cases in the US started to climb. Having low blood oxygen levels doesn’t guarantee you have COVID-19, but it’s one of the major symptoms of the disease. I had read horror stories of people who waited too long to go to the hospital and had died in their sleep because they didn’t realize their levels had dipped overnight. You should always check with a physician if you are experiencing shortness of breath (another symptom of COVID-19), even if a pulse oximeter says…