What is the conceptual, physiological basis for NP calculation?

Discussion in 'Power Training' started by doctorSpoc, Jan 10, 2014.

  1. bing181

    bing181 New Member

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    No it wouldn't.

    In any case, in response to the OP, all nicely covered in post #2 above:

    "The aim is provide a more accurate way to track the physiological cost of your efforts."

    Which it does - and which is all it's trying to do.
     


  2. swampy1970

    swampy1970 Well-Known Member

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    At what point do the Police show up and arrest you for being an old fart just wearing shorts on a stationary bike in a park within earshot of little kiddies?
     
  3. An old Guy

    An old Guy Member

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    While that might be your claim, there is no support for that claim.

    In particular, there is no support that NP (TSS) is any more accurate than AP (work done).

    ---

    Without a percise definition of "physiological cost" there is no substance in your comment.
     
  4. An old Guy

    An old Guy Member

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    I think you are showing too much interest in "little kiddies."
     
  5. swampy1970

    swampy1970 Well-Known Member

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    Saying that you set up a trainer in the middle of a park is right up there with the "climbing long hills at 400watts" and doing intervals that you described earlier. I don't know about everyone else, but when I was much skinnier and fitter my best single 1 minute effort was almost 170% of my FTP. At an absolute push there might have been a slight chance of almost doing two intervals at that output - almost being the operative word and after more than a minutes rest.
     
  6. smaryka

    smaryka Member

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    Yes, exactly. 160% for a minute climbing, then 0% for 30 secs descending is a ridiculous effort more than a handful of times, let alone an hour.
     
  7. RapDaddyo

    RapDaddyo Active Member

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    Actually, I think AOG was suggesting 1min at 160%FTP with 1min at 0%FTP for an hour. That ride would produce an AP of 80%FTP (as he said) and an NP of ~134%FTP. That's a ride file I'd like to see (assuming a true FTP). Take into consideration the fact that the 160%FTP efforts will gradually deplete AWC due to the long half-life of a part of AWC recovery. I know only one thing for sure: I cannot do that ride.
     
  8. dhk2

    dhk2 Active Member

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    Agree. I tried a test last week at the Y, on one of their Cybex trainers. Started out at 1 min on/1 min off, with an output of about 160-165% of my estimated FTP. After the first one, went to 2 minutes rest between intervals (easy spinning). Got to just 5 intervals before I decided to stop because the legs were getting "toasty".....ie, starting to tighten up with slight pain at the end of the interval. Probably could have done a couple more, but it would have been tough. After this little session, I was surprised to feel a mild training effect in my legs, like I'd done a fairly hard and hilly club ride of 40 miles or more.

    Note, I'm just a casual club rider now, 66 years old. On these Cybex trainers, estimate my FTP at 160 watts. My intervals were done at a 265w target, which corresponds to a convenient "24 mph" on the trainer display. Based on this one workout, I plan to continue doing these intervals at least once a week, rather than the old standard 20 min at 90-95% est FTP I've been doing for years . Will see if I can expand the number of intervals up to 10, keeping the 2 min rest in between.
     
  9. An old Guy

    An old Guy Member

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    Without reviewing what I wrote in this thread, in the past I have been more specific:

    The duration and intensity are chosen to suit the hill and to keep your heart rate below LT.

    I tend to do 45-50 seconds on the hill I have. My heart rate is 160-170 (LT 175) at the top and 110-120 at the bottom. My cadence gets up to 70 quickly at the bottom and tops out about 100-110. I am usually sloppy about the power. I shoot for 160-180% peak and 150% at the top.

    But each person needs to determine what works best.

    ---

    Your comment about "true FTP" is valid. Which is why I have tried to be careful in explaining how anyone can do this.

    It is unnecessary for you to see my data file. acoggan has data on a number of other people doing something similiar. It is not like no one else can do it.
     
  10. smaryka

    smaryka Member

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    Well I took it to mean only the time needed to descend was the rest interval... not many one minute climbs take a full minute to descend! ;) But yes even with one minute recovery it's hardly an NP buster. You'd think if you were trying to disprove the theory of NP, you'd pick a real NP buster instead, not something fairly impossible.
     
  11. RapDaddyo

    RapDaddyo Active Member

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    Well, now he seems to be backing away from his claim. Now he shoots for a peak of 160%FTP. And, of course, no evidence in the form of a ride file (because it's so common). Why am I not surprised.
     
  12. An old Guy

    An old Guy Member

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    Like most people who attack hills my power at the bottom is often too high.
     
  13. An old Guy

    An old Guy Member

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    I am in no rush to start up the hill again.

    I rush up the hill, do a leisure turn, descend, do a leisure turn, wait until my watch indicates it is time to go again.

    ---

    Andy Coggan and acoggan call them NP busters. Not me.

    There is no need to disprove NP since acoggan says it is not science. But if there were a claim that NP was science, one would need to compare what is being measured to the NP computation. Of course, that would mean that all but one of Andy Coggan's claims of what is being measured are invalid. Of course, the acutal comparision would show the last one was invalid.
     
  14. doctorSpoc

    doctorSpoc New Member

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    @alienator
    Ok... I'm a bit confused... as far as I can see... we are in violent agreement as far as physics is concerned then [​IMG]
     
  15. doctorSpoc

    doctorSpoc New Member

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    Old Guy's trolling and impossible/idiotic proofs aside... he makes one good point... and that is that PM, NP etc are NOT science with a capital S... although they seem to make lots of sense and are useful, Coggan changed Bannister's models (which ARE scientifically verified) quite significantly to make them practical to be used as an everyday training aid... those changes have not been verified robustly... the only backup for them are some loose, anecdotal correlation to trials.. this part of his argument is actually correct.
     
  16. An old Guy

    An old Guy Member

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    You are too generous in relating support for Bannister's model. On TrainingPeaks.com - the site that Andy Coggan shills for, says that it is not clear what the model models - it is a black box, one cannot collect enough data to make the model accurate for an individual - one would need to do a performance test every 4th day if not several times a day, and an individual's fit to the model is not accurate enough to base a training plan on.

    And that is for "Bannister's models (which ARE scientifically verified)." And it is part of the TrainingPeaks sales pitch.

    So buried in the sales pitch is a statement that what you are buying into is a big lie.
     
  17. quenya

    quenya New Member

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    I think that AOG is mistaking a scientific theory, with a mathematical model. It was developed with an understanding of of the underlying physiology, but it really is more of a statistical manipulation of data than theory or physical law. That said, of the people who produce NP busters has anyone done an IF of 1.34 for anywhere near an hour?
     
  18. acoggan

    acoggan Member

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    1. Good synopsis.

    2. Highest I have ever seen is 1.18.
     
  19. acoggan

    acoggan Member

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    Not entirely true:

    http://www.ncbi.nlm.nih.gov/pubmed/19910822

    But, yeah, if you wanted to know just how much more coaching art is required vs. using the full-blown impulse-response model (w/ all its limitations and testing requirements), additional formal studies would have to be performed. End-users, OTOH, are generally more focussed on getting on w/ trying to win races.

    EDIT: BTW, my Vulcan friend, you might be interested in this presentation (from the 2006 ACSM annual meeting):

    http://www.slideshare.net/acoggan1/making-sense-out-of-apparent-chaos-analyzing-data-from-onbike-powermeters

    (Note that the presentation doesn't include two back-up slides I had handy, demonstrating that the normalized power algorithm is remarkably insensitive to changes in either the smoothing window (or approach) or the weighting exponent. Only if you change both do the numbers change significantly.)

    EDIT2: This is also semi-related:

    http://www.ncbi.nlm.nih.gov/pubmed/24104194

    (There are a couple dozen other scientific studies that have employed my various metrics, but these two are most directly related to the issues at hand.)
     
  20. doctorSpoc

    doctorSpoc New Member

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    ...agree 100%.

    What rational, if any did you use when you chose the smoothing and weighting exponent you did in fact choose?
     
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