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(Pw:Hr), Aerobic Decoupling


1. What is (Pw:Hr), Aerobic Decoupling?
2. How to use it?
3. Questions

What is (Pw:Hr), Aerobic Decoupling?


Aerobic Decoupling is a ratio between Normalized Power and Heart Rate between the first and second part of your workout.

((NP1/HR1) - (NP2/HR2))/(NP1/HR1) * 100


NP1 – Normalize Power from first half part of the workout
NP2 – Normalize Power from second half part of the workout
HR1 – Heart Rate from first half part of the workout
HR2 – Heart Rate from second half part of the workout

How to Use it?


It can be used as a “rate of fatigue”. It could be used during long aerobic workouts, long climbs or time trials. Aerobic Decoupling reflects how heart rate is reacting to our input which is power.

For the best result in tracking Pw:Hr it is good to check it during steady, below threshold workouts, going over your FTP is not the best reflection because the reaction of power and heart rate is way different timewise.

A good example can be endurance 2,5 hours workout with 1-hour tempo zone interval. Going as steady as possible, we can check the results of Pw:Hr. The goal is to be below 5%, if it is lower then 5% it is good information that our body can handle this type of effort and we can move to zone 4 workouts. If it is higher then 5%, we still should spend more time on improving our endurance and tempo zone or take a little break it can be a sign of being overloaded. If you did this type of workouts before at this period of preparation and your Aerobic Decoupling was higher then 5% it is a sign of being tired and overloaded with your training plan. Take a break!



1. In most cases, it’s very difficult to control or make the riding only ‘aerobic endurance’ Because we meet uphill or downhill. Then, we cannot measure EF or Decoupling?

2. Whenever I check Training Peaks analysis, I can see those figures even if my workout was not totally ‘aerobic’ Then, how should I understand the figures? Does TP calculate EF or Decoupling only as extracting my aerobic riding during the whole workout? or are the figures calculated simply considering my whole workout performance?



Actually, I got a chance to hear from Joe about it and yes this is true, but we can “extend it” to zones 3 and 4 as long as a workout is steady. This is the most important thing, it should be as steady as possible (VI should be 1 or very close).

If it is interval training, group ride or race, you shouldn’t be even looking at EF or Pw:Hr!

Another thing we could use it are longer steady uphills, so if you are doing 4×20 min uphill you can compare EF from those intervals, but something they have to be as steady as possible.

No, unfortunately, TP in not pulling just your aerobic zone, that is the way those numbers are not accurate during interval rides, group rides, etc.

I hope it helps with a better understanding of the subject.

Coach Damian

Damian is a head coach and founder of Cyklopedia, which was created with one goal to help everyone be faster cyclists by structured training plans, healthy recipes, and nutrition plans. Damian is racing and coaching for over 10 years, working with athletes all around the world.


  • Hi Damien,

    I’ve been reading several articles on “Cyklopedia” over past few weeks as I have Joe Friel’s “Fast After 50” in my collection of fitness books (yes I’m well over 50) and whilst I don’t buy into everything he says, some of it has merit. In particular, I’m increasingly buying into the logic behind basing a training regime on FTHR and have moved my training plan to this for 2021 – we’ll see what it brings in coming months.

    Reason for my note is I think your idea of Aerobic Decoupling, as explained above, is unfortunately flawed.

    If we take your example in the above article ( re tempo intervals, you have a fairly narrow HR range to stay in tempo, which means the average for the first tempo interval is going to be pretty much identical to the second interval. If it’s not then you’ve gone out on Z3 for some part of either or both intervals. For this to work you would need to be doing each interval at a fixed speed/load/conditions for each interval which will mean your HR will drift upwards through time. For example, running on an indoor treadmill at fixed speed & gradient is the perfect solution.

    Am I missing something?


    • Coach Damian Coach Damian says:

      Hello, thank you for your insights, Aerobic Decoupling should be taken from longer workouts, and you’re right they should be as steady as possible, but only long workouts can put enough stress on our aerobic system so you can see if your watts will start moving around. Aerobic Decoupling will tell you if you are ready in terms of your Aerobic base, to extend the time of your workouts and also move to higher training zones, does that help?

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