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Rick Murphy's Normanalized Power Thread
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TOPIC: Rick Murphy's Normanalized Power Thread

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24284

  • Ron Ruff
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I don't have enough knowledge (or ambition) about physiology to do this myself. There is more going on than just depleting reservoirs, and I expect it to be fairly complicated. But there are people who *do* have enough knowledge of the processes that are occuring and it seems odd that this isn't done in a more direct way.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24287

  • Kirk
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I think that one first might want to identify the prevalence and magnitude of what problem in what population of power users that such a model would benefit. That way, there is an outcome-based goal in mind when thinking about the relevance of different things.

Shifting gears here...that general theme is one thing about all this gizmo stuff that I just don't understand. It's like a cure for disease X without even being able to show that disease X exists and results in underperformance...let alone efficacy compared to other methods. While I am a proponent of power and have personally benefitted from the insight and performance it has provided, I'm not convinced that using power will really make much of a difference in most people if they just apply first principles...training is "robust" eh?

If someone wanted to assign a single number to things for the intellectual challenge, I think there is still a lot to learn and a lot of confounders. So even though there are a lot of knowledgeable folks out there and lots of suggestions about what influences a given rides impact, there is a lot of unquantified stuff (IMHO). For example, I think that the distribution of work as it relates to proximal training history plays a role in a ride's impact, and that relationship can change independently of say, one's 20MP or 60MP fitness level. Therefore, I think it will be challenging to find a benefit that results from applying a global number for an individual ride. I think there are some basics to start from if one wants to explore it though. This study below looked to evaluate the overall metabolic impact of variable vs. constant exercise at the same AP when the variable protocol isn't confounded by excessive cumulative "on" time.

http://www.ncbi.nlm.nih.gov/pubmed/17024627

They hypothesized that since it is well established that the metabolic responses to increases in exercise intensity begin to transition from linear to non-linear above critical power, that the inclusion of the 30s "spikes" well above CP within an average power would result in a measurable difference between trials. Since they did not find a statistical difference but instead found a trend towards reduced total glycogen utilization in the variable protocol, the suggestion to me is that 30s is too short for that intensity for there to be a global impact which is distinct from simply acknowledging that the distribution of work was different. IOW, the "higher powered" motor-units in the variable protocol were certainly stressed differently (they probably weren't even recruited in the constant effort), the lower powered fibers were stressed less in the variable effort, and the work was distributed over more motor-units in the variable effort (perhaps that is responsible for the trend in reduced glycogen utilization?). IMHO, someone who does lots of spikes like this will likely have less of a distribution-specific impact than someone who does them very rarely.

So for practical applications, I think one can basically look at kj's below about 20MP (there is probably a transition zone from linear to non-linear or "steeper" linear between CP to about 20MP ), kj's in total, put efforts >95% of 20MP and longer than 1 minute into a cumulative "bin", and look at a ride's power histogram after that for more distribution-specific work accumulation (scatter the plot stuff like spikes and sprint-work would show up here...in the odd event that someone forgot that they did those efforts). I think that all of that together in conjunction with the non power-data factors, one can get a gross picture of a ride to compare to what has been done in recent training. Beyond that I think there is an art to it...and adding more numbers to the stack can be misleading. I just haven't seen what problem is solved by trying to equate a fill ride and a chunk ride...they are still different rides.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24288

  • djconnel
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In that paper, they compare the following:

1. 90% of C P (close to 87.8% F T P, using a A W C/C P = 90 seconds) for 30 minutes.
2. 20% at 158% C P (154.1% F T P), 80% at 73% C P (71.2% F T P), avg = 90% C P = 87.8% F T P

NP for this exercise, neglecting smoothing, was 87.8% F T P and 107.5% F T P. The ratio was 122.4%.

With smoothing, the ratio will be less, depending on the ratio of the intervals to the smoothing time constant. Details? This would be a real "G P buster" if the intervals were sufficiently larger than 30 seconds.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24289

  • Ron Ruff
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Kirk wrote:
While I am a proponent of power and have personally benefitted from the insight and performance it has provided, I'm not convinced that using power will really make much of a difference in most people if they just apply first principles...training is "robust" eh?


Up until now my only "method" was to ride hard in various ways and rest when necessary. I'm hoping to improve on that...

For example, I think that the distribution of work as it relates to proximal training history plays a role in a ride's impact, and that relationship can change independently of say, one's 20MP or 60MP fitness level. Therefore, I think it will be challenging to find a benefit that results from applying a global number for an individual ride.


I think it is completely unnecessary to ascribe a number to a ride. It makes more sense to model the athlete's physiological and metabolic "state". Adaptations and recovery are part of this so they certainly carry over. In other words at any particular time a person will be in various states of depletion and recovery... whether racing or sleeping. The model runs 24/7 and is modified by things like "how do you feel?", as well as performance.


IOW, the "higher powered" motor-units in the variable protocol were certainly stressed differently (they probably weren't even recruited in the constant effort), the lower powered fibers were stressed less in the variable effort, and the work was distributed over more motor-units in the variable effort (perhaps that is responsible for the trend in reduced glycogen utilization?). IMHO, someone who does lots of spikes like this will likely have less of a distribution-specific impact than someone who does them very rarely.


Makes sense. Now, the other question is what is happening over time? If this protocol is kept up, will the variable guys be depleted sooner of later? How about the next day? How does intake of calories effect this before, after, and during riding? What is the effect of longer rest periods between intervals? What happens if the intervals are 1 min long? 5min long but lower in intensity? Etc. Although it is nice to do this in a lab, the easier way would be to recrute some coaches and their clients to perform these tests...

So for practical applications, I think one can basically look at kj's below about 20MP (there is probably a transition zone from linear to non-linear or "steeper" linear between CP to about 20MP ), kj's in total, put efforts >95% of 20MP and longer than 1 minute into a cumulative "bin", and look at a ride's power histogram after that for more distribution-specific work accumulation (scatter the plot stuff like spikes and sprint-work would show up here...in the odd event that someone forgot that they did those efforts). I think that all of that together in conjunction with the non power-data factors, one can get a gross picture of a ride to compare to what has been done in recent training. Beyond that I think there is an art to it...and adding more numbers to the stack can be misleading.


There is an art to everything... but I still believe this process could be codified much better than what I've seen. In that case the art would be in tweaking the parameters in the model to match the athlete.

Do you treat all KJ above 95% 20MP the same? That doesn't seem quite right. Maybe from a fuel depletion scenario, but not in terms of muscle trauma.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24290

  • Kirk
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Ron Ruff wrote:
There is an art to everything... but I still believe this process could be codified much better than what I've seen. In that case the art would be in tweaking the parameters in the model to match the athlete.


Yeah, this is essentially what experienced athletes/coaches do everyday within what they can control and around what they can't (the latter is very important IMHO). Do you want to capture that in a model in some way?

Do you treat all KJ above 95% 20MP the same? That doesn't seem quite right. Maybe from a fuel depletion scenario, but not in terms of muscle trauma.


For practical purposes, yes, but while noting that longer chunks are more challenging/productive at a given power than shorter chunks to a point. I haven't yet seen the practical utility to dissecting any closer than that.

Muscle trauma can occur at any intensity, but WRT intensities above 20MP, I think familiarity plays a significant role...IOW, if you haven't used those fibers/stressed the connective tissues similarly in the recent past you are going to pay a greater price than if you do efforts like that all the time.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24291

  • Kirk
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djconnel wrote:
In that paper, they compare the following:

1. 90% of C P (close to 87.8% F T P, using a A W C/C P = 90 seconds) for 30 minutes.
2. 20% at 158% C P (154.1% F T P), 80% at 73% C P (71.2% F T P), avg = 90% C P = 87.8% F T P

GP for this exercise, neglecting smoothing, was 87.8% F T P and 107.5% F T P. The ratio was 122.4%.

With smoothing, the ratio will be less, depending on the ratio of the intervals to the smoothing time constant. Details? This would be a real "G P buster" if the intervals were sufficiently larger than 30 seconds.


...and if one drops the on and off powers by say, 150w each, the ratio gets really big.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24292

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That's true....

One clarification, though: being a so-called "G P" buster is if the workout yields G P > F T P for one hour. In this case, it is 7.5% over F T P for a half-hour. Normally riders would only be able to exceed F T P by 5% in a half-hour (assuming AWC / CP = 90 seconds). So with smoothing, it may well fall under the "G P buster" threshold. For example, if these hard efforts were 30 seconds each, with 30 second smoothing, only for an instant would their bodies experience the stress of the full power of the effort, according to the algorithm.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24294

  • kraig
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djconnel wrote:
That's true....



yeah, pretty interesting, huh?

What's the error, in this case, considering the claim by it's inventor that "GP represents the metabolic strain of a constant power effort"?
-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24295

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Kirk wrote:
www.ncbi.nlm.nih.gov/pubmed/17024627

They hypothesized that since it is well established that the metabolic responses to increases in exercise intensity begin to transition from linear to non-linear above critical power, <snip>


yeah, that is an interesting study - it's nice to see folks formulating a testable hypothesis.
-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24296

  • Kirk
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rmur wrote:
Kirk wrote:
Kirk wrote:

Yeah, it's clear that the math inflates lower average powers more than higher powers. This is particularly interesting since folks can generally also vary their power with greater amplitude when the average power is lower. That's sort of a double bonus eh?


It's actually more than a double bonus...why even use an exponential weighting in a general sense? Heck, power fxns don't fit a full spectrum of power-lactate data well (a linear fit is better eh? ya know, even if you are dead your lactate isn't zero) and even the sections where a power fit is OK...a linear fit is nearly identical. Why choose an exponent based on that data? Anyone have any ideas? Again, this is also dependent on applying fxn's which are based on gross changes on average power? Maybe Rick and clear things up a bit with the data, protocol, and application stuff?

So maybe it's a double bonus^4?

Thoughts?


Hi Kirk,
I suspect if you looked hard enough that it's out there in the public domain now ... that's about all I can say. Except the bit about the duck of course


FWIW, I found a pdf. The linear and power fits are practically identical for that section of data (only >~0.75LT was presented/measured). For at intellectual purposes, I still think it would be interesting to hear the protocol to see if that influenced how the data came out and also the general thoughts on the applicability issue.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24297

  • Kirk
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Ron Ruff wrote:
kraig wrote:
Yes, I agree - the variable duty cycle exercise is another good way to demonstrate the non-physiological basis of the math equation - especially when placed in the context of really long efforts.


Or like last weekend's 52 mile ride. I've done this loop a bunch of times as a "TT". Best AP was 205W. On Sat I rode with a couple of other guys and there were a lot surges and attacks, drafting, etc. Lots of easy riding too. AP was 187W... but GP was 235W! Guess I just got a lot stronger all of a sudden.


That's an interesting observation. My experience on both a practical and academic level is the example of a long, easy, fill ride where the inclusion of few non-taxing, short spikes at that lower average power make GP suggest you did an entirely different ride. Most commonly, this different ride based on GP was something that I can do at a constant effort (it doesn't break my power-duration limits), but the difference between GP and AP is quite high without any particular reason it seems. Just another example of the underbuster issue I've commonly experienced.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24298

  • Kirk
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djconnel wrote:
I admit my post maximizing G-S-B was misrepresentative, as I don't believe it's ever recommended someone maximize G-S-B for optimal performance, rather that it be tuned to balance fitness and freshness. Since fitness is measured in C-T-L, this suggests each sort of event has a particular linear combination of C-T-L and A-T-L which should be maximized, where the weighting on C-T-L is positive, the weighting on A-T-L is negative, and the magnitude of the C-T-L coefficient is greater than that of the A-T-L coefficient. But I've already gotten myself into enough trouble with these idle mathematical speculations lately, as tempting as they may be.


I think that evaluating the GSB concept is difficult. There are issues involving differences in training philosophies, quantifying the magnitude of any effect (above and beyond whether one prefers a positive or negative value for the outcome of choice), controlling the environment surrounding personal best trials (including motivational and placebo/nocebo effects on trial performances), other confounders, and combinations of the above...which would make comparing outcomes based on using GSB vs. not using GSB in different populations very challenging, I think. It would be interesting though.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24299

  • kraig
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Kirk wrote:
rmur wrote:
Kirk wrote:
It's actually more than a double bonus...why even use an exponential weighting in a general sense? Heck, power fxns don't fit a full spectrum of power-lactate data well (a linear fit is better eh? ya know, even if you are dead your lactate isn't zero) and even the sections where a power fit is OK...a linear fit is nearly identical. Why choose an exponent based on that data? Anyone have any ideas? Again, this is also dependent on applying fxn's which are based on gross changes on average power? Maybe Rick and clear things up a bit with the data, protocol, and application stuff?

So maybe it's a double bonus^4?

Thoughts?


Hi Kirk,
I suspect if you looked hard enough that it's out there in the public domain now ... that's about all I can say. Except the bit about the duck of course


FWIW, I found a pdf. The linear and power fits are practically identical for that section of data (only >~0.75LT was presented/measured). For at intellectual purposes, I still think it would be interesting to hear the protocol to see if that influenced how the data came out and also the general thoughts on the applicability issue.


Nice work digging that one up.

I wonder how many people are aware that the curve "fit" GP is based on, as presented/measured in that pdf you dug up:

1) isn't based on the powers one might encounter over the entire power duration spectrum


and



2) also has linear and power fits that are practically identical over the range that is presented in the pdf?

yeah, I'd also be curious to see Rick Murphy disclose the secret/censored protocol that he claims he can get, and his thoughts on the applicability issue.
-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24300

  • rmur
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fonts are too small Craig ...
GIZMO marketing specialist

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24301

  • Kirk
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Kirk wrote:
While I am a proponent of power and have personally benefitted from the insight and performance it has provided, I'm not convinced that using power will really make much of a difference in most people if they just apply first principles...training is "robust" eh?


I have to say though that power allowed me to complete a move away from a belief that the more training (in gross terms) one can tolerate the better to one more in line with the idea that the fewest total "doses" of relevant training types can be at least just as productive. To some degree power allowed me to discount the meaning/value of gross, overall training load, relative to the composition of training, in terms of training productivity. So to be accurate, power did help me to change and consolidate what I view as first principles.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24305

  • kraig
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Kirk wrote:

...to one more in line with the idea that the fewest total "doses" of relevant training types can be at least just as productive. To some degree power allowed me to discount the meaning/value of gross, overall training load, relative to the composition of training, in terms of training productivity.


yeah, in my case, a power meter didn't really do that - I mean, I had a power meter for the better part of a year, before someone persuaded me to take on the stripped down experiment

It didn't take long for that lesson to sink in, and ultimately pay dividends for me.

Could I have learned this lesson using a stopwatch and a few hills? Probably, since both are quantitative, though, the power meter does have a bit (not too much, though!) less noise under those circumstances - which might have led to the lesson being learned a bit sooner, I reckon.

But really, it was less the power meter, and simply more about the different way of approaching/thinking about things (as you mentioned) that worked for me.

So, power is what it is, but it's not just numbers that can lead to understanding what matters and what doesn't.

What you talk about, and have talked about, kind of reminds me of this pic I took while visiting portland last summer:

-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24306

  • Jack Watts
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Kirk wrote:
Kirk wrote:
While I am a proponent of power and have personally benefitted from the insight and performance it has provided, I'm not convinced that using power will really make much of a difference in most people if they just apply first principles...training is "robust" eh?


I have to say though that power allowed me to complete a move away from a belief that the more training (in gross terms) one can tolerate the better to one more in line with the idea that the fewest total "doses" of relevant training types can be at least just as productive. To some degree power allowed me to discount the meaning/value of gross, overall training load, relative to the composition of training, in terms of training productivity. So to be accurate, power did help me to change and consolidate what I view as first principles.


That's funny--in a rather mind-numbing thread on the wattage list Andy C asked me 'what changes to my training have I made using a PM', since in his (pretty much accurate) words, I rely more on a qualitative rather than quantitative approach. The above comment is pretty much exactly what I said.

I'll also say that even training with a PM for going on 10 years, I still find that on occasion it provides some me some information that leads me to 'alter the dose', even though I have a pretty good idea by this time of what works for me. IOW, after using a PM for a long time, I could get by almost as well without one--but I prefer not to!

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24308

  • kraig
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Jack Watts wrote:


That's funny--in a rather mind-numbing thread on the wattage list ... <snip>


let me guess -> more GP "chewbacca defense" lawyerin' antics???

and yes, I'm with you on the whole "PM's are nice to have" deal.
-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24309

  • Jack Watts
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kraig wrote:
Jack Watts wrote:


That's funny--in a rather mind-numbing thread on the wattage list ... <snip>


let me guess -> more GP "chewbacca defense" lawyerin' antics???



I can only laugh, since I was the one accused of 'lawyerin' antics! Someone asked for some examples of rides/suggested workouts that 'busted the gizmo', and I simply provided some. What ensued was a couple of hours of my life I won't get back--but who knows, maybe some people will at least think a little more critically and not put so much *faith* into what are, IMO, unproven concepts.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24311

  • Kirk
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Jack Watts wrote:
Kirk wrote:
Kirk wrote:
While I am a proponent of power and have personally benefitted from the insight and performance it has provided, I'm not convinced that using power will really make much of a difference in most people if they just apply first principles...training is "robust" eh?


I have to say though that power allowed me to complete a move away from a belief that the more training (in gross terms) one can tolerate the better to one more in line with the idea that the fewest total "doses" of relevant training types can be at least just as productive. To some degree power allowed me to discount the meaning/value of gross, overall training load, relative to the composition of training, in terms of training productivity. So to be accurate, power did help me to change and consolidate what I view as first principles.


That's funny--in a rather mind-numbing thread on the wattage list Andy C asked me 'what changes to my training have I made using a PM', since in his (pretty much accurate) words, I rely more on a qualitative rather than quantitative approach. The above comment is pretty much exactly what I said.

I'll also say that even training with a PM for going on 10 years, I still find that on occasion it provides some me some information that leads me to 'alter the dose', even though I have a pretty good idea by this time of what works for me. IOW, after using a PM for a long time, I could get by almost as well without one--but I prefer not to!


Ha! I'm experiencing some deja vu...circa 2005 or so...both from here and at the old topica wattage. Lots of lost hours...

Yeah, I still learn from my powermeter too in some way, even when I'm just playing around on my commute and not really trying to get fit for a race. Last year it was how bloody fast I can get in shape (power wise). I definitely don't want to go back to the non-power days here either!

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24331

  • Kirk
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Kirk wrote:
rmur wrote:


Hi Kirk,
I suspect if you looked hard enough that it's out there in the public domain now ... that's about all I can say. Except the bit about the duck of course


FWIW, I found a pdf. The linear and power fits are practically identical for that section of data (only >~0.75LT was presented/measured). For at intellectual purposes, I still think it would be interesting to hear the protocol to see if that influenced how the data came out and also the general thoughts on the applicability issue.


FWIW, this article has somewhat similar data:

http://www.ncbi.nlm.nih.gov/pubmed/3403447

The relationship between time to exhaustion (12-75MP) and blood lactate upon fatigue; and the relationship between relative intensity and blood lactate (during 30 minute trials) have better linear fits (R^2 = 0.84 and 0.94 respectively?) than power fits. Does anyone have any thoughts or see mistakes on my part looking at that data?

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24338

  • kraig
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Kirk wrote:
Kirk wrote:
rmur wrote:


Hi Kirk,
I suspect if you looked hard enough that it's out there in the public domain now ... that's about all I can say. Except the bit about the duck of course


FWIW, I found a pdf. The linear and power fits are practically identical for that section of data (only >~0.75LT was presented/measured). For at intellectual purposes, I still think it would be interesting to hear the protocol to see if that influenced how the data came out and also the general thoughts on the applicability issue.


FWIW, this article has somewhat similar data:

http://www.ncbi.nlm.nih.gov/pubmed/3403447

The relationship between time to exhaustion (12-75MP) and blood lactate upon fatigue; and the relationship between relative intensity and blood lactate (during 30 minute trials) have better linear fits (R^2 = 0.84 and 0.94 respectively?) than power fits. Does anyone have any thoughts or see mistakes on my part looking at that data?


seems linear to me - not sure why one would try to force a power fit to those data.
-kraig

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24354

  • SteveB
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Ron Ruff wrote:
Or like last weekend's 52 mile ride. I've done this loop a bunch of times as a "TT". Best AP was 205W. On Sat I rode with a couple of other guys and there were a lot surges and attacks, drafting, etc. Lots of easy riding too. AP was 187W... but GP was 235W! Guess I just got a lot stronger all of a sudden.
Other possible reasons:
a) maybe you weren't riding up to your potential on those solo rides.
b) maybe you paid better attention to nutrition and fueling in the 24 hours before and during the group ride.
c) maybe the extra motivation of the group scenario made you push yourself harder. (It always does with me.)
d) maybe (cumulative) fatigue was more of an issue on the solo rides. People tend to have better short-term power (re: the surges you mentioned) when they are better rested.

Also: the average, or mean, is, IMO, not a great way to describe a non-normal distribution, which I'm sure your power distribution was in both cases.

Re: Rick Murphy's Normanalized Power Thread 8 years, 9 months ago #24355

  • Kirk
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SteveB wrote:
Ron Ruff wrote:
Or like last weekend's 52 mile ride. I've done this loop a bunch of times as a "TT". Best AP was 205W. On Sat I rode with a couple of other guys and there were a lot surges and attacks, drafting, etc. Lots of easy riding too. AP was 187W... but GP was 235W! Guess I just got a lot stronger all of a sudden.
Other possible reasons:
a) maybe you weren't riding up to your potential on those solo rides.
b) maybe you paid better attention to nutrition and fueling in the 24 hours before and during the group ride.
c) maybe the extra motivation of the group scenario made you push yourself harder. (It always does with me.)
d) maybe (cumulative) fatigue was more of an issue on the solo rides. People tend to have better short-term power (re: the surges you mentioned) when they are better rested.

Also: the average, or mean, is, IMO, not a great way to describe a non-normal distribution, which I'm sure your power distribution was in both cases.


In all fairness since he has the perspective of riding the course as a TT a bunch of times, it could also be that the group ride was an underperformance for that course for most of same reasons stated above. He did the solo rides as TT's too, so they are likely to be close to maximal efforts for that course. IME, group rides/races are almost never maximal efforts for the duration. I'd also say that d) is certainly the case in some circumstances, but it is likely at least just as dependent on the composition of the training and how that is integrated as it is on some total value...assuming that motivation is equal and non-training influences are equal (big assumption there I think!).

In terms of specifically describing the distribution of work, yeah, means don't describe that.

Re: Rick Murphy's Normanalized Power Thread 8 years, 8 months ago #24387

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I had this one forwarded to me:

"The greater the difference between average watts and gizmo power, the greater stress the body feels as compared to a steady, more constant, power output."

http://velonews.com/article/88262/atoc- ... av-larsson

I guess this means that Hunter and Dirk didn't check out the plots in this thread that demonstrate, in a variety of ways, that at lower average powers, GP doles out some pretty good bonus watts? )

anybody care to share these ToC files, that trainingpeaks has posted, with me in a non-proprietary format?
-kraig

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