Advice on completing PP/MPA Workouts? SMART Difficulty Spiral?

Xert - Workout Details (

What was scheduled:

1x40s @600W
e.t.c. with the intervals reducing in length and increasing a little.

What I got:


This is quite a lot different. I obviously struggled but got through the first few. But they were never anything like what I was prescribed. As soon as I started to struggle, the next interval jumped in difficulty to counterbalance the fact that I didn’t drag MPA down perfectly.

And because it’s ERG mode and there is a 3s delay in ramping power you can never drag MPA perfectly. You spent an entire interval chasing those 3s of missed watts on top of the watts you need to produce. Every single time you hit an interval, you lose a few seconds of dragging MPA down, so the next interval is ALWAYS harder.

I sort of dragged myself to the second set with a few breaks thinking it would reset, but the lost MPA is held.

The first interval of the next set became 1x30s @ 1000W followed by 6x30s at 700W.

Obviously, that was the end of my workout.

What I find a bit confusing is that at no point was the workout anywhere near representative of anything I had the capacity to do, not was there any way of preventing this spiraling increase in difficulty as XERT tried to make up for MPA.

Do SMART intervals just sort of not work very well for such high intensities? I found them ok around threshold and below but at these levels going from 600w repeats to 800w repeats - I can’t keep up with the way it shifts targets. There seems to be no way of actually salvaging a healthy workout from a session like this. As soon as you fail to perform something perfectly you are fucked and you may as well give up your session.

Thoughts appreciated.

Oh and I have 5 years of 5-10hrs a week of data so should have a valid signature.

Interesting you bring up this workout because we had a similar support complaint from another user today and I myself did this workout today and thought it should be changed. It definitely over-penalizes on the intensity intervals if you miss a beat. I knew what was going to happen so stayed on top of it the whole time: Trainer Activity on February 29, 2024 by Armando M on Strava. Struggled at times since this is a challenging workout but managed ok in the end.

We went ahead and updated it today to make it a bit less penalizing. The on-intervals are now XSSR and the recovery are Target MPA so you still have to be on your game for this workout but if you’re off, you’ll get a bit harder rest-in-between interval rather than have to put out higher power on the on-intervals. Should make it easier to complete. Fun workout though and interesting that it gives you a greater feel for the fatigue sensation from the up and downs during each set.

Hi, and thanks for the quick reply.

Your workout track looks to me a lot like you completed that on level mode rather than ERG.



This means that you weren’t punished automatically for the 3s of ERG spin up, and then when you fell behind occasionally a bit later / faded - you were not punished with an interval that was significantly harder.


I totally get the idea of MPA drawdown-based-intervals, but I just can’t work out why my STARTING interval was 200W higher than predicted based on my signature. Even at the expected target power it would be a difficult workout.

And then 1000W for 30s repeats later on?

I think there was something with the scaling of the punishment that didn’t make sense here. Maybe an XSS/Hr target would make more sense at this level of intensity? Ah - I see you have made them XSS/hr targets, that make sense!

My first set would now be a 40s descending ramp from 547->457.

Real power data doesn’t look like this. You should turn smoothing off or use your power meter data for best results. ERG mode will work with powermatch with your power meter. This is how I ran it and how we recommend it if you have a power meter and a smart trainer.

What brand/model trainer do you have?
If Wahoo, this video explains why you don’t want power smoothing enabled (aka fake news).

Also, if you watch the workout on the Remote or Session Player you can monitor the Cadence Optimizer gauge and spin up to suggested RPM range before the high watt interval starts. That will minimize any jump in watts (or spiraling) at the start of the interval and the trainer will settle into the target watts quickly. This also helps you complete high watt intervals because you didn’t spend much time above target which shortens how long you can hold the watts.
I may be spinning at 75 rpm during a low watt RIB (rest-in-between) but will jump to 120 rpm two seconds before a red spike hits. The transition is much smoother.
The CO gauge indicates a rpm range for whatever the target watt requires.
For MIXEDMODE workouts this isn’t a big concern because you control the interval start/end through gears/cadence. On difficult workouts where you are struggling you can always switch to Slope mode and monitor the rainbow gauge to attain targets to the best of your ability. Slope mode also lets you control RIBs and skip an interval now and then if that’s what it takes to complete a workout versus failing it.

NOTE TO XERT TEAM: Please add AUTO/Slope toggle mode to EBC options in the next version. When enabled tapping AUTO switches to Slope and vice versa. There is no ERG, Resistance, or Off to cycle through when this option is enabled. :wink: