Cardiac drift monitoring Dr. Stephen Seiler

Good morning everyone. My first time writing on the forum. After reading the article, How to achieve the biggest prize of polarized training: Durability, I have downloaded Dr. Seiler’s chart that monitors decoupling throughout training for wko and I find it very interesting.
I have certain doubts:

  • What does it mean that at the beginning of the activity the uncoupling line is above the baseline (1)?
  • What conclusion can we draw when it is below?
    Would a more detailed explanation be possible?
    It may not be important and it’s only worth focusing on controlling when the decoupling line goes past 1.
    Thank you very much in advance.

Hi Adrian,

Above baseline ‘the power comes easy’. You haven’t reached a steady state yet. You are probably still warming-up / riding below your FTP.

Below baseline ‘you are unable to maintain power output with the same internal stress level’. Your stamina is insufficient to keep the power steady.

To improve the point of decoupling (“have it occur later”) you can do extensive aerobic work (“go longer in HR zone 1 / 2 / 3 in a 5 zone model”)


Thank you very much for the reply. So I understand that in the initial part of a workout that is above the baseline expresses a relationship where the power “comes easy” with respect to the heart rate and vice versa.
This relationship could not be due to initial fatigue and therefore the pulse does not react in the same way with respect to the pulse? Could this be a good indication of high stress?
I work with HRV to control this but I find it interesting to be able to establish some relationship.
Thank you very much.

There can be lots of reasons why the decoupling is different compared to another day. It will not tell you why so be careful interpreting this value.

If the heart rate is low compared to power, that is usually a sign of fatigue indeed.
Conditions during training must be equal to interpret the value well. So level of fatigue, environmental conditions, muscle pains, time between food intake and training etc etc.
Lots of variables. Therefor i usually only look at HR/Power for the the middle section of my training if ‘all felt well’ and train as much as i can in the same location.

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