https://www.frontiersin.org/articles/10.3389/fphys.2020.550572/full#h5

I’m familiar with the general opinion regarding the usefulness of HRV as a recovery indicator. I have been tracking my HRV for a while (HRV4T) and I too have had periods where the recommendations were questionable. At other times, the recommendations have stayed consistently inline with what my legs/body is telling me. Either way, I find it interesting to track and dig into some of the correlations after accumulating a couple months worth of data.

WRT the linked article, I’ll be the first to admit that most of the science and math in these type of calculations is over my head, but I still found it an interesting read and thought others here might also enjoy it. The authors admit that more studies need to be done, but given the importance of determining one’s AeT, it is interesting that it could correlate to a metric that may be consistent for both fit and unfit athletes independent of their HR at AeT.

I’ll stick to a HR drift test, but I still thought it was pretty cool.