Sorry, I was unable to find a good discussion on this.
I have recently set some new power records. I am comparing them to my fitness this time last year. Is it better to compare my NP or my Avg?
For example, I did a hard group ride on Sunday. Normalized around 310 for 20 minutes, but only averaged 285. (This was after doing an hour at 250) I had to stop during the 20-minute effort to take my battery off and on (thanks, Ax) and then had to close a gap. Comparing that power to last year, would it be better for me to look at average or np? Curious for this and future stuff when I am trying to set a new power record while sprinting for 5th place on the Sunday social.
Both have their time and place in review, but generally NP for long durations with changing intensity give you the best picture of the toll on body and fitness needed.
Neither is better. They tell you different things.
Average power is a good metric when power is consistent - long intervals, time trials. Etc. if your NP and AP are wildly different then it implies you’re not consistent in pacing this kind of effort.
NP is a good metric when the power output is inconsistent - races, roads with repeated steep climbs. A higher NP (and it’s almost always higher) indicates a spiky effort.
Personally when comparing power records as a gauge of fitness, I’d use AP.
NP is also not much use in short intervals - as it requires 30s of data.
They can both be used for comparison, it’s just important to compare apples to apples as much as possible. AP is generally a more reliable point of comparison because there is less context to consider. With NP, you have to consider the context in which the power was generated when comparing 2 efforts.
When looking at mass start races, NP is normally a better point of comparison because there is usually a lot of coasting and surging. But there is still context that has to be considered. If I did a 5 hour race that included a bunch surging mixed with easy periods and it ended in a group sprint, I might have an NP of 230 watts for the entire race. Compare that to a race where I was holding on to the lead group for the first hour and then got dropped and did a time trial to the finish over the next 4 hours, I might end up with a NP of 250+. But I might have been much fitter with the 230NP effort vs. the 250NP effort over the same time. And that 230NP might have felt harder if it surged all day compared to a steady TT effort. I still like to use NP for comparing race efforts, but they need to be races that played out in similar fashion. I’m much more likely to compare segments within a race that are selective. NP for the first 1-2 hours of a gravel race usually tells a good story, especially when looked at with the context of how strong I rode the rest of the race.
One thing to be cautious of with NP is using it to predict/compare to AP pacing. Lot’s of people can do a much higher NP for 20/40/60 minutes compared to what AP they can do for those durations. This is particularly true for athletes with a punchy power profile.
Yeah. The physiological toll is nonlinear with power and goes up faster than power goes up. NP was created to account for this and be a more accurate representation of how hard you worked.
