Heart Rate Variability vs. Heart Rate
What is the difference between Heart Rate and Heart Rate Variability? What are the pros and cons of each? When should each metric be applied?
What are RR intervals?
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.