MPA declines non-linearly even at a fixed power above threshold. Where do the hidden kJ’s of energy at the start of efforts come from? Creatine phosphate?
There aren’t any hidden kJ in the system.
The line represents your ability to generate power at any given time, not how much of your High Intensity Energy you have left.
Actually, you can see High Intensity Energy on the power chart - it is the area between MPA and TP lines.
Surely it’s the area between power and threshold power as HIE is effectively the integration of power above threshold.