Speaking the same language: A simple HRV conversion tool
Alan Couzens, M.S. (Sports Science)
April 12th, 2015
One of the more frustrating aspects of HRV tracking for me, as a coach to a number of athletes, is pulling all of the various proprietary HRV scores together into a common meaningful currency to compare 'athlete to athlete' and also to compare my athletes' numbers against the research.
You see, most of the hardware/app manufacturers have come up with their own proprietary HRV 'score', which (presumably) enforces loyalty to their product. From a business stance, I get this, but from a research stance it makes things a little difficult to compare athletes directly or against the large amount of research studies centered around the relationship between various HRV numbers (most typically raw rMSSD) and changes in performance and adaptation in real life athletes.
For this reason, I've prepared the following calculator to help you (and me!) to compare 'apples to apples'
Most of the apps utilize the natural logarithm of raw rMSSD multiplied by a proprietary conversion factor. I don't want to find myself in a courtroom so I won't give you these numbers but, in the words of a very wise man "it's worth a Google" :-) For a starting point, Simon from ithlete talks about their algorithm at the bottom of this post from their blog Leading researcher in HRV Andrew Flatt, also talks about the difference between 'raw' rMSSD and some proprietary HRV 'scores' in this post..
Once you've identified the number that your HRV system is using to multiply its lnRMSSD number by, you can plug it into the calculator below (change 'Conversion factor' from 1 to whatever multiplication factor your system uses) to get a 'raw' rMSSD eqivalent for that number to compare against the research or to talk to me about your numbers without me hurting my brain with the conversions (my rMSSD is bottoming out today, can you tell? :-)
Anyhow, hopefully you will find the calculator useful and hopefully it can lead to easier & more fruitful sharing of data in the future
Convert from HRV 'score' to rMSSD
Convert from rMSSD to HRV 'score'
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