Variability index (NP / avg power) versus time-in-zone for cyclocross pacing analysis

As I’m just wrapping up my CX season and thinking about areas to improve for next year, and pacing in particular. The comments in episode 186 about Keegan Swenson’s CrossVegas race ( got me thinking.

I’m curious about whether the closeness between average power and NP is really reflective of the effort, or is an artifact of the 30 second averaging in NP. I think it would be really interesting to compare that to the time spent in different power zones over the course of the race. The issue is that say 15s/15s microbursts at 150% FTP / 40% FTP will produce identical NP and average power, but I certainly wouldn’t describe microbursts as a “smooth” effort, or anything like a steady 95% sweet-spot effort. In my experience, cyclocross efforts can be pretty similar to microbursts, especially for flatter courses where you are accelerating out of corners and then soft-pedal into the next one. On the other hand, a course with significant say 1 minute climbs (with corresponding rests on the descents), then you can get a really big gap between NP and average.

So if Keegan actually spent a high fraction of the time during the race around threshold, then I would believe the “smooth power” theory. But I would actually expect to see a lot of time at very low power, and a lot of time at VO2max or higher.

Is the power file for Keegan CrossVegas ride available publicly? I couldn’t easily find a link, but if it is maybe I could answer the question for myself.