NP v's Average Power

A light bike doesn't replace good fitness.

Moderator: Moderator Team

dynaserve
Posts: 272
Joined: Fri Jul 18, 2008 8:25 pm
Location: UK

by dynaserve

The over day I did 3x10min even pace hill intervals and averaged 333W, with NP 333W

Today I did 2x10min crazy crit type attacks and averaged 306W, with NP 339W and 370W.

I'm interested in the correlation between average & NP - Can I expect to drag my 10min average up to 370W then?

(I can give my 5min max, 20min max, FTP etc for reference, but I'm interested in general thoughts on this. I guess as the time intervals get longer the more average and NP converge?)

Cheers!

by Weenie


User avatar
WMW
in the industry
Posts: 855
Joined: Sun Jul 29, 2012 2:59 pm
Location: Ruidoso, NM

by WMW

I can't make much sense of your post, but I can generate a much higher NP doing intervals than I could ever do with a steady effort. That isn't supposed to be the case but everyone is different.
formerly rruff...

User avatar
Tinea Pedis
Posts: 8417
Joined: Sat Mar 14, 2009 6:08 am
Location: Geelong
Contact:

by Tinea Pedis

I think what he's asking is if he can push his average to what he is able to generate normalised.

Which given what normalised represents, being able to match that with an average power interval of the same length should be doable.

dynaserve
Posts: 272
Joined: Fri Jul 18, 2008 8:25 pm
Location: UK

by dynaserve

TP - Correct and I'm encouraged you think it's doable!

User avatar
Tinea Pedis
Posts: 8417
Joined: Sat Mar 14, 2009 6:08 am
Location: Geelong
Contact:

by Tinea Pedis

Alex Simmons is happy to use NP as either a check for FTP or to generate a FTP figure

http://alex-cycle.blogspot.com.au/2008/ ... -sins.html

so with that in mind, my experience is that you should be able to come close to those NP figures as an average power.


Jumping on the ergo tomorrow and giving it a go is the best way to answer the question though.

User avatar
WMW
in the industry
Posts: 855
Joined: Sun Jul 29, 2012 2:59 pm
Location: Ruidoso, NM

by WMW

dynaserve wrote:TP - Correct and I'm encouraged you think it's doable!


For most people that is approximately correct... but not for all.

When I do 20 60sec intervals with 90sec rest, I can get an NP more than 10% higher than I can ever do with a steady effort. For me the calculated NP is about twice as high over AP as it should be.
formerly rruff...

JimV
Posts: 63
Joined: Tue Apr 05, 2011 6:57 pm
Location: Chicago

by JimV

NP overestimates power by so much it is not worth looking at. GoldenCheetah has two normalizing power averages that are much more realistic as to what one would be able to produce in a steady effort.

User avatar
Tinea Pedis
Posts: 8417
Joined: Sat Mar 14, 2009 6:08 am
Location: Geelong
Contact:

by Tinea Pedis

Next pertinent questions would be:

- what power meter are you using

- what head unit

- are you taking NP off the head unit or after letting GC or TP crunch it?

As Garmin's certainly overestimate the displayed NP.

jmorgan
Posts: 21
Joined: Thu Jan 17, 2013 3:37 am

by jmorgan

The issue is NP is not meant to be used over a 10min interval. NP is useful for longer durations. NP isn't useless if you know what it represents and how its calculated.

Read Alex's blog for a better understanding.

http://alex-cycle.blogspot.com/2013/03/ ... rt-ii.html

If you are looking for how much power you can sustain for 10 or 20min intervals just look at your power duration curve.
2012 Cervelo S5 Team

JimV
Posts: 63
Joined: Tue Apr 05, 2011 6:57 pm
Location: Chicago

by JimV

Its still a worthless number. If you have to interpret its value based upon VI and length it looses its value as a tool for comparison. Most people get there best hour long efforts from road races and crits, and that is were NP is most useless.

User avatar
WMW
in the industry
Posts: 855
Joined: Sun Jul 29, 2012 2:59 pm
Location: Ruidoso, NM

by WMW

I agree. I've tried to goad the physiology experts into coming up with a better normalizer, but there was no interest.

IMO it would make much more sense to look at your full spectrum of max output (1min, 3, 5, 10, etc) and compute the stress on your body based on how close you came to those limits.

For instance, my 60min (FTP) might be the same as another guys, but if my max 1min is 600W and his is 500W, and we do a bunch of 1 min intervals at 450W, he is accumulating a lot more stress than I am, and will not be able to continue as long.
formerly rruff...

User avatar
Tinea Pedis
Posts: 8417
Joined: Sat Mar 14, 2009 6:08 am
Location: Geelong
Contact:

by Tinea Pedis

You're talking more TSS Ron and less NP there. And in that example the rest he would need to get his NP the same as yours (that he has the same FTP as you notwithstanding) would mean you should (in theory) both still reach the one hour mark in close to the same state.

But I do wholeheartedly agree that something needs to be improved as far as a TSS goes that truly captures anaerobic work done within a ride.

jmorgan
Posts: 21
Joined: Thu Jan 17, 2013 3:37 am

by jmorgan

That's what Bike Score was supposed to do, but as it turns out there isn't that much of a difference between it and TSS.
2012 Cervelo S5 Team

jmorgan
Posts: 21
Joined: Thu Jan 17, 2013 3:37 am

by jmorgan

JimV wrote:Its still a worthless number. If you have to interpret its value based upon VI and length it looses its value as a tool for comparison. Most people get there best hour long efforts from road races and crits, and that is were NP is most useless.


You don't need to interpret it based on VI. All you need is sufficiently long enough time. Its designed to take variability in power from say a race and the sprint efforts required to stay with the group and normalize them so you can compare them to something like your FTP. If your NP from a race is 350w and the race was an hour, but you had your FTP set at 300w. NP is saying 350w is closer to your true FTP.

Thats it. Nothing special. Not hard to understand.
2012 Cervelo S5 Team

User avatar
WMW
in the industry
Posts: 855
Joined: Sun Jul 29, 2012 2:59 pm
Location: Ruidoso, NM

by WMW

Tinea Pedis wrote:both still reach the one hour mark in close to the same state.


The example I gave earlier was 20x1min intervals where I can beat my NP for a steady effort of the same duration by >10%. The other mythical rider would not be able to accomplish this. If I dialed back my effort to a level that would result in *his* max, then I'd be reasonably fresh and he'd be exhausted. So not the same at all.

Another thing that is wonky is the small difference given a 100% effort vs say 95%. They are both afforded nearly the same amount of stress, but in reality the 100% effort is *much* more taxing. By 100% I mean cross-eyed, coughing blood, legs refusing to function, and collapse at the end. If I ride a 40K TT or anything longer at 100%, then I'll need several days to recover, while a 95% effort would be easy.
formerly rruff...

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post