FTP estimation via 60mins NP / NP Calculation

Feature Requests
1

I posted this on Bikehub but didn’t realise there was a forum here :wink:

I have questions regarding eFTP and ride FTP (and NP)

Intervals.icu this my 99er ride imported straight from Garmin connect.

The last hour is a 318-320w NP depending where you pick the peak 60mins, so I would assume ride eFTP should be at about that instead of 285w ?

Recently I have done 10 mins intervals with one rep at 371w that bumped my eFTP up to 330w.

My first question is : is there is a specific reason why you give more credit to a one time 10mins effort than a 1 hour NP in terms of FTP Estimate ?

2nd question is there a tool to see our peak 60 mins NP among all rides and within one ride ? Sauce for Strava allows you to see your peak 60mins on each ride that’s pretty cool, but you can’t see a peak for a season or specific period.

Lastly. For the same ride, Sauce on strava gives me a peak 60mins NP at 326w, I wonder why is there about 6w difference base on the same data ? if there are different formula to calculate NP ?

Cheers, once again thanks for the amazing work on intervals.icu :heart:

1 Like
2

Thanks. eFTP is calculated using many model power curves derived from real power curves for lots of athletes. So it works with average power for x duration and not normalised power. I don’t think using NP would be a good idea. Someone really good short power and doing many short intervals would get higher NP than someone doing a steady state effort but they might very well have lower FTP.

I have calculating normalised power curves on the todo list. It has come up a few times.

Before I do that I will make it possible to plot “best 5m/20m/60m power etc.” for each activity on the /fitness page. I added the server side code for that a little while ago. Just need to do the UI side of things.

I don’t know why Sauce has different NP. Maybe the 60m best is not the last hour but an hour a bit before that? I don’t know what formula they use but its probably the same. Might be how dropouts are handled?

2 Likes
3

Don’t wanna troll too much here but is NP of any real interest for training or racing ?

4

This article explains the difference between NP and AP, specifically on a 1 hour ride and how both quantify how the effort felt.

1 Like
5

Thanks but as as a triathlete, I aim for a continuous effort so average power should be close to NP and as a cyclist aiming for long endurance rides, I rely on average/real power to estimate energy consumption.

If I would do a mountainous tri then I would have a look at NP, but IMHO we give a little bit too much importance on NP biaised on the fact that it’s a higher number…

6

There’s no right or wrong, but rather why both are valid.
That’s why they give an example of a continuous effort vs HIIT training.