This is the HUUUUUGE difference between Xert’s 3 parameter model and the 2-parameter (and even 3-parameter) Critical Power model. In those models, W’ is only capacity-limited, so those models would indicate that you could sprint 5000 W for 5s if your W’ is 25 kJ (or 25,000 W for 1s). However, with Xert, we know that you’re not only capacity-limited by HIE, but that capacity is also rate-limited by MPA.