Instead, it is active during the night while you sleep. This value usually lies between 90 and 100 percent.įitbit doesn't measure this saturation manually at the press of a button, like the Huawei Watch Fit oder Honor Watch ES do. The oxygen level in our blood stream (SpO2) indicates, to what percentage the hemoglobin in the lung is filled with oxygen. The hemoglobin in our red blood cells plays an important role in supplying our body with oxygen. This effect can be enhanced with relaxation exercises through Sense and the Fitbit app. The test is conducted at rest, which in itself can reduce the heart rate. If the Sense registers changes in the skin's electrical conductivity during a 2-minute scan, this can indicate emotional stress. If the Sense recognizes any heart rhythm irregularities, this could indicate atrial fibrillation, which doctors connect to an increased risk of stroke.Īnother feature is the EDA scan, which detects electrodermal activity of the skin. To do an ECG, you have to place your index finger and thumb on the stainless steel ring around the display for 30 seconds. Fitbit received the EU's CE certification ( Conformité Européenne), which is important for medical devices, in September. The Fitbit Sense logs changes to skin temperature and can also create an ECG (electrocardiogram). The heart rate sensor remained accurate within 1-3 beats compared to the belt in our test with an increased heart rate, which we simulated in performance mode. There weren't any major differences between the two results. We checked the precision of the device's heart rate sensor by comparing it to a chest strap from Polar. The Sense monitors the user's heart rate 24/7 and emits warnings when limits are exceeded or dropped below, according to Fitbit.

Fitbit sense review