After using the SPO2 tracking feature on the Vivosmart 4 for a number of months, it is now clear that the device is wildly inaccurate. When compared with a dedicated finger pulse oximeter, the Garmin data is extremely volatile and shows desats down to ~80% regularly. Garmin is entering dangerous territory by claiming this device can measure SPO2 at all. While they do make note that this device should not be used for medical diagnosis, erratic SPO2 data on these devices will inevitably do more harm than good as users assume the data can be interpreted at somewhere near face value. However, it is now clear that the SPO2 feature shouldn't be interpreted at all. This forum is already littered with users claiming very similar grievances. The feature, in many ways, is worse than no feature at all as long as it remains this inaccurate.
