Metabolic rate based on heart rate variability considering level 3 of the ISO 8996

The ISO 8996 report, at level 3, a methodology to estimate the metabolic rate using the heart rate.
Is there a component/model that define this value considering, for example, monitored data taken by a wearable?

Can you elaborate on your question? If I remember correctly, Part 3 of ISO 8996 provides a formula for predicting metabolic rate or MET given an individuals HR, age, and body mass. Are you looking for this formula?

Yes, I am looking for .gh model that implement the Part 3 of ISO 8996 that allows to estimate the metabolic rate using heart rate.

I would be surprised to find an existing component that does that but it would not be hard to create! The formula is quite simple and is based on the table:

Inputs are Age, Mass, and HR.
where HR is beats per minute (bpm).
Result will be in Watts. Divide by 1.8 (surface area of the human body - dubois formula) to get W/m2.
For MET, divide the W/m2 by 55.

I am sure that you aware that there is some degree of inaccuracy with Part3 of ISO 8996. The standard rates this method has having a +/- 10% accuracy, whereas a VO2 study is the most reliable way to determine MET.

Yes, of course the method described in Part3 of ISO 8996 is less accurate (it is correct an +/- 10% of accuracy) of the method based on the monitored CO2 production and O2 consumption. But is more convenient and very inexpensive. There is also a recent paper [1] that revises the Part3 of ISO 8996. You have to consider also that the metabolic values for different activities (annex A of ISO 8996), may have errors as high as 20% [2].

Hey dude you have the ISO 8996 PDF?..if u have u cand send me? Please is too hard find her
I’m Peruvian my english is not good sorry