Your Reflex Active smartwatch doesn’t just track your steps or heart rate: it also keeps an eye on something a little more scientific: your SpO₂ levels. You may have seen this term in your watch’s health data or on the companion app, but what does it actually mean?
And why is it useful to monitor? Let’s break it down.
What Does SpO₂ Mean?
SpO₂ stands for “peripheral capillary oxygen saturation.” In simpler terms, it’s a measure of how much oxygen your red blood cells are carrying through your body.
It’s expressed as a percentage; and for most healthy adults, normal readings are typically between 95% and 100%.
Oxygen plays a vital role in how your body functions. Every breath you take delivers oxygen to your lungs, where it binds to red blood cells and travels through your bloodstream to fuel your muscles, organs, and brain. When your SpO₂ level dips,
it means your body isn’t getting as much oxygen as it should, which can leave you feeling tired, dizzy, or short of breath.
How Does My Smartwatch Measure SpO₂?
Your Reflex Active smartwatch uses light-based sensors to estimate your blood
oxygen levels: the same principle used in hospitals with fingertip pulse oximeters, just in a more wearable form.
On the back of your watch, small red and infrared LED lights shine gently onto your skin. The sensors then measure how much light is absorbed and how much bounces back. Because oxygen-rich blood and oxygen-poor blood absorb light differently, your watch can calculate an approximate SpO₂ reading by analysing the reflected signal.
It’s a completely non-invasive and painless process, all done in seconds, right from your wrist.
Why Does My Watch Track SpO₂?
Monitoring your SpO₂ is another way your smartwatch helps you understand your overall wellbeing. Oxygen saturation can fluctuate depending on your activity, altitude, and even how well you’re sleeping.
During workouts, your SpO₂ reading can help you see how effectively your body is using oxygen. After intense exercise, tracking your oxygen recovery levels can also show how quickly your body bounces back. Some users find it helpful to check their SpO₂ at night, as dips in oxygen can indicate sleep-related breathing changes.
Your Reflex Active smartwatch brings all this data together, so you can view patterns and averages over time. Through the Reflex Active Red or Reflex Active Blue app, you can track how your oxygen levels change throughout your day, giving you a fuller picture of your health beyond just your heart rate.
Getting the Most Accurate Reading
For the best results, wear your watch snugly on your wrist; not too tight, but secure enough that the sensors maintain light contact with your skin. Keep the back of the watch clean, and avoid moving your arm too much during a reading, as motion can interfere with the light signal.
Cool skin, tattoos, or very low light conditions can sometimes affect accuracy, so it’s best to measure when you’re still and relaxed. If your reading seems unexpectedly low, try taking another one after a short rest.
