Calculating LT1 and LT2 approximately without a blood test?

I used the Python script an ran it on my 2021 base rides files. While I don’t get to see alpha changes in real time as I exercise, the script uses some basic linear regression to derive the aerobic threshold heart rate. Interestingly enough, the prediction is almost in line with coggan Z2 limit 83% of LTHR, consequently very far from Friel’s 89% LTHR

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