What is Coefficient of Variation
Coefficient of Variation (CV) is a standard statistical method to look at variation in averages.
In the case of HRV, it looks at variation in HRV between weeks, instead of days. CV is showing the variation between data points in a series. In this case, our HRV CV is displaying the variation in your daily HRV Morning Readiness scores for the 7 days leading up to the day you are viewing. So if you are viewing HRV CV for a Sunday, it includes all the days since last Sunday in it already: Monday to Monday, Tuesday to Tuesday, etc.
If your HRV CV is 10%, you have a roughly 10% change in HRV from day to day for the past 7 days. When plotted on a chart, each day is showing the HRV CV for that day, which includes the 7 days leading up to that day. The chart is visually showing the change in how your HRV changes over time.
Recent research shows that HRV CV can provide additional insight into the recovery and performance (speed, VO2max, HIIT times) of advanced trainees.
For more information, please check out our guest blog post below: