Intensity monitoring with EPOC / HRV

XC;
You may be interested in reading this: https://uphillathlete.com/why-we-stopped-relying-on-hrv-apps/ In my fairly extensive experience using HRV testing apps with several professional athletes I finally abandoned the use.

EPOC is the brain child of Heiki Rusko who is one of the grand old men of exercise science. He is one of the leaders in HRV etc. So, who am I to dispute his wisdom. From my understanding EPOC is also a HR based training load measurement. It relies upon the HR zones you tell the device.
For real time intensity monitoring for endurance athletes in variable terrain sports like XC skiing HR is still the best metric. For post exercise training load monitoring, Training Peaks Performance Management Chart tops anything I have ever used in 30 some years of looking.

Scott

The way I understand the difference between using HR and EPOC (and using HRV during exercise itself) is accumulated fatigue. Exercise HRV is analyzed and converted to an EPOC value.
So, in theory, long-term accumulated fatigue can be carried from one training session
to another and visible in the EPOC value.

From my understanding, you may therefore have the same heart rate, but very different EPOC values (due to accumulated fatigue). There is a “learned” component to EPOC so that
HRV can be converted to EPOC (and % of VO2max).

Say that you can display EPOC value in real-time as you train, I was wondering if there is
any advantage to using it over HR. In particular, I had two things in mind:
1. Getting around cardiac drift problem. Perhaps EPOC (or % of VO2max if you could
measure it directly) is more robust than HR. Assuming that your VO2max is fairly constant,
you could then train at say 90% of VO2max which could mean different HR on a different day.

2. If you can’t measure pace/speed/power reliably (due to varying terrain, weather, snow
conditions, etc.), but maybe you know that a particular pace corresponds to a certain
percentage of VO2max, you may be able to hit the target pace more accurately.

These are just speculations as I have actually never seen any articles on how to use
this in practice in real-time (only as post analysis). I don’t even know if there is an
actual correlation between target pace and %VO2max.