Heart Rate (HRV) vs. Heart Rate (HR)
As you may know, HRV and heart rate are calculated differently and should be analyzed differently. We wrote a blog post that discusses the uses of both: HRV vs. Heart Rate
Another question we get often is how HRV and heart rate can be used to detect overtraining syndrome. Heart rate can actually increase OR decrease as a response to overtraining. It depends on the type of training and the individual. Often high volume endurance training can lead to a decreased resting heart rate in overtraining. The research of Paul Laursen and Dan Plews mentions this, amongst others. This is another reason that HRV can be helpful when heart rate does not always paint the full picture.
We recommend tracking all changes occurring by utilizing the tagging and journal feature in the app to help track these symptoms.
HRV cannot be calculated from HR.
Heart rate (HR) is measured in beats per minute. It does not require exact times – just the average of the beats in a given time period. For example, 60 beats per minute HR could mean 1 beat per second or it could mean an average of 1 beat every 0.5s, 1.5s, 0.5s, 1.5s, etc.
While heart rate focuses on the average beats per minute, heart rate variability (HRV) measures the specific changes in time (or variability) between successive heartbeats. The time between beats is measured in milliseconds (ms) and is called an “R-R interval” or “inter-beat interval (IBI).”
The recommended minimum number of times per second that a heart rate variability sensor should sample for a beat is 250. This can be referred to as 250Hz. Any monitor with a lower sample rate should not be considered HRV-accurate.