Basic Heart Rate Variability (HRV) is the measured changes of the time intervals between successive heart beats. Unlike Heart Rate (HR) that averages the number of heart beats per minute, HRV looks much closer at the small fluctuations of the heart that occur in response to internal and external events.
Elite HRV has built in breathing guides that allows you to use your respiratory system to gain control over your cardiovascular system and nervous system and track the effects.
The Morning Readiness gauge indicates your state of relative balance. In other words, it is comparing your HRV values to your recent past and telling you whether your Autonomic Nervous System (ANS) is in a similar state or if it is swinging widely outside of your norm.
Heart Rate Variability can be affected by changes in circadian rhythm, hormonal shifts, and acute stressors throughout the day. Also, whatever you were doing before taking a reading has a very strong impact on the reading results.