You can use the trend in your basal heart rate to understand the progress of your training, and as a reference for your activity plans.
*It is possible to see the trend in the effectiveness of the training you have done from the change in your basal heart rate during a certain period.
This can be used as a point of reference for your training, and also leads to increased motivation for your next training session.
(Note) It is necessary to wear the device and measure your heart rate while sleeping in order to make use of this feature.