Peak Power


My peak power in the progression chart and fitness signature seems to decline automatically in 5W steps every day unless I do a workout with a max effort to keep it at its real value (i.e. what I am capable of). It looks like this is the default coded behavior of Xert, is that correct?

I rarely go all-out even for a few seconds on my rides as I do not race/sprint, but this implies I need to in order to keep my fitness signature, and especially MPA, accurate. Else I need to manually input my peak power regularly. Can anyone advise if this 5W/day decrease is Xert behaving as expected?


Chris, the 5W per day in your case represents the maximum that your PP will drop. It is atypical to see this pattern so discretely. The number depends on your other signature values.

But yes, you should be looking to keep your PP value “honest” by doing some efforts near peak. With some patterns in the data, Xert may infer your FTP is higher than it is if PP is underestimated. The frequency at which you need to do so depends on the specific values.

This will likely improve substantially in Phase II of our prediction model rollout.

Is PP even related to training load? I can’t see any correlation between PP and CTL when I take a cursory look at my 6 years worth of power files.

Rohan, We are seeing a relationship between peak Training Load and PP. If you look at the Strain chart, you can identify your peak intensity strain. There is a correlation across a wide group of athletes. This will come into play in Phase II of our Fitness Prediction rollout as there are unique time constants.