MPA does not decline during hard workouts

I am a little unclear on how MPA is calculated. Right now it appears to me that only efforts above threshold cause depletion. Here is a link to a recent trainer workout that was fairly hard for me to complete yet shows no decline in MPA throughout the workout.

I actually set it at 95% of the prescribed power level so I would be able to complete it. Why does the MPA remain so flat even though I was close to failure on each interval? At least part of the problem is that outside of Xert my FTP is set to 305 while within the program Xert gives me an FTP of 326. Prior experience with setting and confirming FTP suggests 326 may be too high.

All that being said on a couple of group rides I uploaded, MPA comes close or actually touches my current power just as I failed so at least in real world examples it seems to work correctly (at least at first glance). Here is an example from today

https://www.xertonline. com/activities/d1mntxxhyfep95td

So I am interested in explanations as to why many rides which I would perceive as hard or barely doable still show flat MPA curves. Thanks!

Are you using the same power meter for both situations? Also, which power meter(s) are you using?

I use P1 pedals outside and a Cyclops Hammer smart trainer inside (typically with Trainer Road). I have found power readings to be very similar between the two when I have done comparison tests. I do not use Power Match because I do not like Trainer Roads implementation.

Use our app’s powermatch and it will tell you how well the power meters match up (providing both slope and intercept of the relationship). User’s have said they prefer our implementation. I suspect that the issue is either this or that your indoor sessions are much more difficult for you due to other limiters.