Monitoring your blood oxygen levels may not seem as exciting as step counting or be as obvious in its benefits as something like sleep tracking, but it's still a useful option for managing your health with an Apple Watch. Just think of it as one more metric you can keep an eye on to make sure the organic mech suit your brain is piloting is operating smoothly.
Generally you want the amount of oxygen in your blood to sit at around 95% and up, as it's a good sign that your lungs are doing a good job of supplying this precious element to your body's other systems. Readings below a 95 could be an indicator of pushing yourself too hard during a workout, possible respiratory problems, or absolutely nothing because by Apple's own admission the watch feature isn't intended (read: reliably accurate enough) for medical purposes. Waterproof Digital Watch
Should you want to make use of blood oxygen monitoring for non-medical purposes, though, that's definitely something you can do with your Apple Watch — regardless of December 2023's pulse oximeter debacle. As long as you have an Apple Watch Series 6 and newer (or any model of Apple Watch Ultra) and an iPhone 6s and later with the most recent version of iOS installed, you're good to go.
Assuming you have the necessary hardware, and live in a region where the feature is currently available, getting set up is a breeze.
Sports Heart Rate You may receive inaccurate results due to cold temperatures, a high (over 150 bpm) heart rate, or bruises, tattoos, or other markings on your skin blocking the sensors.