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TTE / FTP Question
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Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing?
Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Depends how well trained you are and what you have trained.
You can extend time to exhaustion without getting a higher FTP.
You can do it and get a lower FTP.

So as always, it depends.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Yes, you can certainly have substantial changes in TTE whilst only having negligible changes in mFTP.

I've noticed this happen particularly when I put in a hard effort at longer time periods (>>TTE e.g. 120 mins).
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Re: TTE / FTP Question [awenborn] [ In reply to ]
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awenborn wrote:
Yes, you can certainly have substantial changes in TTE whilst only having negligible changes in mFTP.

I've noticed this happen particularly when I put in a hard effort at longer time periods (>>TTE e.g. 120 mins).

I know it can happen in WKO4, but I'm asking if it can happen physiologically. TTE can change dramatically if you feed in new data, but has the physiology of the rider changed?

I can't see how just one or two rides can change a riders physiology, obviously though WKO4 can only work with the data it has been fed.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing?
Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?
As has been explained to you ad nauseam, the power-duration curve at these durations is very flat, such that normal day to day variability alone can result in quite a sizeable change in TTE attainable for a given power output. This is normal.

It can also be the result of a change in fitness.

Have a look at a few decent MMP curves and calculate the % variance between ~30-min and ~60min power (being a 100% increase in duration). You'll see that it's like ~5% difference in power, or something of that order.

So it stands to reason that even a 1% change in power output capability (well within day to day variability levels) can result in quite large differences in TTE (e.g. 10-12 minutes) at power levels at/near FTP.

Which is why TTE isn't quoted with any great level of precision.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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My rhetorical question was prompted by the following article on TrainingPeaks.
I'm well aware Andrew Coggan has made it clear many times that TTE is not as accurate as some of his other metrics.

My point is that it would seem TrainingPeaks and some of their coaches do not understand the impreciseness of TTE and may be misdirecting training because they think it is a useful metric. We now have an article posted on TrainingPeaks giving complicated methods of estimating FTP and quoting TTE as a useful metric. They certainly give the impression TTE is an accurate measure of how long one can maintain power at MLSS.

There is a danger that people self coaching or coached by those who put too much store in TTE could be seriously misled and they should be reminded of Andrew Coggan's seven sins.

Here is the article.


https://www.trainingpeaks.com/...w-testing-protocols/
Many popular training methods today are aimed squarely at improving 20-minute power. While improving 20-minute power can be a sign of progress, we don’t know if we’re truly increasing FTP, which is the amount of power that can be put out at maximal lactate steady state (MLSS). While in this state, an athlete will fatigue in between 30 and 70 minutes (known as time to exhaustion, or TTE)1 rather than the traditionally defined 60 minutes. It’s easy to see that FTP is not always 95 percent of an athlete’s best steady-state, 20-minute effort. In WKO4, the Aerobic Anaerobic Contribution chart will show us how power at 20 minutes can be different relative to FTP. This chart is pictured below for a well-rounded elite female road cyclist, and we can see an 11-watt anaerobic contribution at 20 minutes with a power of 279 watts. Her FTP of 268 is 96.1 percent of this power, and she can hold it for about 40 minutes. The second chart below is from an elite male track racer. At his 20-minute power of 262 watts, there is a 24-watt anaerobic contribution. His FTP of 238 watts (at a TTE of 75 minutes!) is 90.8 percent of his 20-minute power.




AlexS wrote:
Trev wrote:
Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing?
Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?

As has been explained to you ad nauseam, the power-duration curve at these durations is very flat, such that normal day to day variability alone can result in quite a sizeable change in TTE attainable for a given power output. This is normal.

It can also be the result of a change in fitness.

Have a look at a few decent MMP curves and calculate the % variance between ~30-min and ~60min power (being a 100% increase in duration). You'll see that it's like ~5% difference in power, or something of that order.

So it stands to reason that even a 1% change in power output capability (well within day to day variability levels) can result in quite large differences in TTE (e.g. 10-12 minutes) at power levels at/near FTP.

Which is why TTE isn't quoted with any great level of precision.
Last edited by: Trev: Jan 22, 18 0:45
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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The sooner people stop wasting their time doing complicated tests to feed into WKO4 and did a proper test as advised by Andrew Coggan from day one the better.

An entire generation of cyclists have got bogged down with thinking FTP is 95% of 20 minute power, and doing 20 minute tests, not even following Hunter Allen's protocol set out in the original book, that was bad enough, but now they are being encouraged to do loads of tests to help WKO4 come up with a decent estimate, when all anyone has to do is measure power over a 40k TT, or a TT of approx 60 minutes, which is what Andrew Coggan has said is the best way to estimate FTP all along.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
... all anyone has to do is measure power over a 40k TT, or a TT of approx 60 minutes, which is what Andrew Coggan has said is the best way to estimate FTP all along.


Andy does not say this now. He used to say this before we had a better, easy to use tool. 60 min CP does not = FTP. It was an approximation. Using the whole power/duration curve, we can estimate closer.

FTP = The highest power a rider can maintain in a quasi-steady-state without fatiguing. Nothing here about one hour.




Geoff from Indy
http://www.tlcendurance.com
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Re: TTE / FTP Question [geoffreydean] [ In reply to ]
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geoffreydean wrote:
Trev wrote:
... all anyone has to do is measure power over a 40k TT, or a TT of approx 60 minutes, which is what Andrew Coggan has said is the best way to estimate FTP all along.


Andy does not say this now. He used to say this before we had a better, easy to use tool. 60 min CP does not = FTP. It was an approximation. Using the whole power/duration curve, we can estimate closer.

FTP = The highest power a rider can maintain in a quasi-steady-state without fatiguing. Nothing here about one hour.




Well he said this on this forum the other day. He still thinks the best way to ' estimate ' FTP is to take the average power during a TT of approx an hour. By ' we ' who do you mean?

Seven deadly sins

http://forum.slowtwitch.com/...st=last-6538379#last
Last edited by: Trev: Jan 22, 18 11:13
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
My rhetorical question
Which suggests no answers are required.
/endthread

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing?
Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?

Am I the only one on this forum that is pig sick of cycling coaches debating FTP/WKO/Testing protocols etc. ad nauseam and trying to slag each other off all the time.

Its a triathlon forum, why can't you go slag each other off all the time on some cycling forums somewhere?

He who understands the WHY, will understand the HOW.
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Re: TTE / FTP Question [earthling] [ In reply to ]
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earthling wrote:
Trev wrote:
Can time to exhaustion at MLSS / FTP be extended without power at MLSS / FTP increasing?
Suppose my FTP is 250 watts and TTE is 30 minutes, if I extend TTE to 60 minutes, wouldn't 30 minute power have increased? Can TTE be extended without increasing FTP?


Am I the only one on this forum that is pig sick of cycling coaches debating FTP/WKO/Testing protocols etc. ad nauseam and trying to slag each other off all the time.

Its a triathlon forum, why can't you go slag each other off all the time on some cycling forums somewhere?
Trev is no coach.

He's a persistent troll that continually seeks to misinform, hence the ongoing game of "whack a troll".

Unfortunately he also infects cycling forums as well.

But that said, no one is forcing you to open up any thread about the topic. I only open perhaps 0.5% of threads on the forum.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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Please explain to me, I don't understand.
Can you improve the time you can hold your power at threshold, apart from increasing your power at threshold?
Is there any literature on this? What methods (if any) are validated to measure this?
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Re: TTE / FTP Question [asgagd] [ In reply to ]
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Ooh, I was just reading about this question, it seems that you absolutely can increase TTE at MLSS without increasing power at MLSS. Without specific training athletes were found to maintain MLSS for 40-50 minutes max. To improve they trained at or near to MLSS which saw TTE improve significantly but power at MLSS improve only slightly.

It's referenced in the Billat review of MLSS. See p416 here.
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Re: TTE / FTP Question [liversedge] [ In reply to ]
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liversedge wrote:
Ooh, I was just reading about this question, it seems that you absolutely can increase TTE at MLSS without increasing power at MLSS. Without specific training athletes were found to maintain MLSS for 40-50 minutes max. To improve they trained at or near to MLSS which saw TTE improve significantly but power at MLSS improve only slightly.

It's referenced in the Billat review of MLSS. See p416 here.
It only requires a small change in power to create a large change in TTE. That's the point. TTE measures are much more sensitive to various influences, including normal day to day variations in capability.

Ask yourself the question - what is the normal change in power demand used between each of the 30+ minute tests used to establish power at MLSS? If you are careful in how you choose the initial test you might be able to do it with 10W increments, but often the tests used have greater power difference.

Even 5W can result in quite a substantial difference in TTE.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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I think you misunderstood Alex,

TTE@MLSS was increased for the same wattage by training 2-3 times a week at MLSS. Power at MLSS itself hardly changed.

Mark
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Re: TTE / FTP Question [liversedge] [ In reply to ]
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liversedge wrote:
I think you misunderstood Alex,

TTE@MLSS was increased for the same wattage by training 2-3 times a week at MLSS. Power at MLSS itself hardly changed.

Alex understood perfectly. You are the one who seems to have missed his point:



(From https://www.facebook.com/.../?type=3&theater)

ETA since your link to Billat's review seems to be broken:

"Unpublished data recently collected by our team confirmed this estimation in non-elite middle aged (41 ± 5 years) long-distance runners. Time to exhaustion at MLSS was increased after 6 weeks of training (two sessions of 30–50 minutes at MLSS per week) from 40 ± 10 to 62 ± 16 minutes (+50%) while MLSSw was only increased by 3.4%."
Last edited by: Andrew Coggan: Jan 25, 18 13:59
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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The TTE@MLSSw is for the NEW value of MLSSw.
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Re: TTE / FTP Question [liversedge] [ In reply to ]
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liversedge wrote:
The TTE@MLSSw is for the NEW value of MLSSw.

...which doesn't change the fact that the two are always going to change disproportionately, because the slope isn't anywhere close to 45 deg.
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Re: TTE / FTP Question [liversedge] [ In reply to ]
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liversedge wrote:
I think you misunderstood Alex,


TTE@MLSS was increased for the same wattage by training 2-3 times a week at MLSS. Power at MLSS itself hardly changed.

Mark

No, I understood perfectly.

It only requires a few watts to create a decent TTE variance. A few watts may not even be measurable/detectable as representing a change in power at MLSS (or FTP) but TTE can increase at the same power.

It's just another expression of the flatness of the PD curve at that point and that training can make it flatter (or not).

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [liversedge] [ In reply to ]
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Whats the error in the MLSS measurement?

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Re: TTE / FTP Question [JasoninHalifax] [ In reply to ]
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JasoninHalifax wrote:
Whats the error in the MLSS measurement?

short version: don't know.

It takes between 2-5 mins to hit MLSS, so no issues in needing more than the 30 minutes to get there.
The increments in power used are, I guess, the error range, I couldn't find any reference to a standard approach.
I suspect its a judgement, indexed off other test results like MAP.

Mark
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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A 3.4% increase in power at MLSS isn't insignificant.

Andrew Coggan wrote:
liversedge wrote:
I think you misunderstood Alex,

TTE@MLSS was increased for the same wattage by training 2-3 times a week at MLSS. Power at MLSS itself hardly changed.

Alex understood perfectly. You are the one who seems to have missed his point:



(From https://www.facebook.com/.../?type=3&theater)

ETA since your link to Billat's review seems to be broken:

"Unpublished data recently collected by our team confirmed this estimation in non-elite middle aged (41 ± 5 years) long-distance runners. Time to exhaustion at MLSS was increased after 6 weeks of training (two sessions of 30–50 minutes at MLSS per week) from 40 ± 10 to 62 ± 16 minutes (+50%) while MLSSw was only increased by 3.4%."
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Talk to Mark. He is the one who said that it "hardly changed."
Last edited by: Andrew Coggan: Jan 28, 18 4:35
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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This graph was pointed out to me the other day. It is rather interesting because the 'small' increase in power is approximately 9% ( 25 watts). This isn't a small increase. The graph also shows that to increase the time to fatigue shown, at approximately 275 watts, FTP has to increase approx 25 watts to approx 300 watts. This is exactly the point I was making earlier in the thread. If you increase time to exhaustion or fatigue you must increase FTP ( note the graph shows 60 minutes as FTP and I use the term only because that is the term used on the graph.)

I also use the word approximately because on a small IPad it's hard to see exactly the watts and seconds, but the point is, looking at that illustration, the so called small increase in power is about 25 watts, about 9%.

Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.

Obviously specific training can alter the shape of the curve but if you improve time to fatigue / exhaustion, say from 40 to 70 minutes, you will almost (I use the word almost because you might be using duff data or software) certainly have increased your power at 30 minutes, 40 minutes and 60 minutes.


Andrew Coggan wrote:
liversedge wrote:
I think you misunderstood Alex,

TTE@MLSS was increased for the same wattage by training 2-3 times a week at MLSS. Power at MLSS itself hardly changed.


Alex understood perfectly. You are the one who seems to have missed his point:



(From https://www.facebook.com/.../?type=3&theater)

ETA since your link to Billat's review seems to be broken:

"Unpublished data recently collected by our team confirmed this estimation in non-elite middle aged (41 ± 5 years) long-distance runners. Time to exhaustion at MLSS was increased after 6 weeks of training (two sessions of 30–50 minutes at MLSS per week) from 40 ± 10 to 62 ± 16 minutes (+50%) while MLSSw was only increased by 3.4%."
Last edited by: Trev: Jun 9, 18 9:54
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Re: TTE / FTP Question [Trev] [ In reply to ]
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You do understand that that is just a schematic diagram that I drew to illustrate the point, don't you? (Actually, apparently not.)
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.
I think this statement illustrates the crux of your confusion regarding 'threshold'. Just about everyone understands what 'threshold' feels like and knows what it's like to ride at threshold. Increase the power much above threshold and you won't be able to sustain it.

As a thought experiment, imagine if that curve that Dr Coggan drew was perfectly flat. There would be no kinks, tails or elbows but the result would be a clear threshold in terms of sustainable power. A threshold is not associated with a drop off in power at a particular duration. A flat power curve is an illustration of a 'threshold' in power.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
You do understand that that is just a schematic diagram that I drew to illustrate the point, don't you? (Actually, apparently not.)

The point is you put up a graph which does not show what you claim it does. Your so called small increase in FTP is approximately 25 watts, 9%, that is not small.

My comments are about the graph, it is of no consequence that you now claim you just made it up. One must quesstion how many graphs or charts you post which you just made up.

Are you now claiming you drew a diagram which is inaccurate?
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
The point is you put up a graph which does not show what you claim it does. Your so called small increase in FTP is approximately 25 watts, 9%, that is not small.

It shows exactly what is stated on the figure. Any change in Y is accompanied by a much larger change in X at the initial Y.

As long as the slope of the line is shallower than 45 deg, that will be true regardless of how much or how little Y actually changes.
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
Trev wrote:
Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.
I think this statement illustrates the crux of your confusion regarding 'threshold'. Just about everyone understands what 'threshold' feels like and knows what it's like to ride at threshold. Increase the power much above threshold and you won't be able to sustain it.

As a thought experiment, imagine if that curve that Dr Coggan drew was perfectly flat. There would be no kinks, tails or elbows but the result would be a clear threshold in terms of sustainable power. A threshold is not associated with a drop off in power at a particular duration. A flat power curve is an illustration of a 'threshold' in power.


It is me who is pointing out that if there is a power threshold it should show up on the power duration curve as a flat area. It is the lack of a clear flat threshold showing on the curve which is one reason I question FTP.
Last edited by: Trev: Jun 9, 18 15:28
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
gregf83 wrote:
Trev wrote:
Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.
I think this statement illustrates the crux of your confusion regarding 'threshold'. Just about everyone understands what 'threshold' feels like and knows what it's like to ride at threshold. Increase the power much above threshold and you won't be able to sustain it.

As a thought experiment, imagine if that curve that Dr Coggan drew was perfectly flat. There would be no kinks, tails or elbows but the result would be a clear threshold in terms of sustainable power. A threshold is not associated with a drop off in power at a particular duration. A flat power curve is an illustration of a 'threshold' in power.


It is me who is pointing out that if there is a power threshold it should show up on the power duration curve as a flat area.
Looks pretty flat to me. Why were you talking about tailing off, elbows and kinks if all you were looking for was less slope to the curve? I think you need to ride more and argue less.
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
Trev wrote:
gregf83 wrote:
Trev wrote:
Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.
I think this statement illustrates the crux of your confusion regarding 'threshold'. Just about everyone understands what 'threshold' feels like and knows what it's like to ride at threshold. Increase the power much above threshold and you won't be able to sustain it.

As a thought experiment, imagine if that curve that Dr Coggan drew was perfectly flat. There would be no kinks, tails or elbows but the result would be a clear threshold in terms of sustainable power. A threshold is not associated with a drop off in power at a particular duration. A flat power curve is an illustration of a 'threshold' in power.


It is me who is pointing out that if there is a power threshold it should show up on the power duration curve as a flat area.
Looks pretty flat to me. Why were you talking about tailing off, elbows and kinks if all you were looking for was less slope to the curve? I think you need to ride more and argue less.

If you think a continuous downwards curve like that illustration is flat, you are confused.
I mentioned tailing off, elbows and kinks because others have referred to them, it's me who argues they don't exist on the curve.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
gregf83 wrote:
Trev wrote:
gregf83 wrote:
Trev wrote:
Another point is how the graph illustrates how the power duration curve in that area, from 1800 seconds to 7200 seconds drops smoothly and shows no sudden tailing off, no thresholds, no elbows or kinks in tails - there is no visible threshold.
I think this statement illustrates the crux of your confusion regarding 'threshold'. Just about everyone understands what 'threshold' feels like and knows what it's like to ride at threshold. Increase the power much above threshold and you won't be able to sustain it.

As a thought experiment, imagine if that curve that Dr Coggan drew was perfectly flat. There would be no kinks, tails or elbows but the result would be a clear threshold in terms of sustainable power. A threshold is not associated with a drop off in power at a particular duration. A flat power curve is an illustration of a 'threshold' in power.


It is me who is pointing out that if there is a power threshold it should show up on the power duration curve as a flat area.
Looks pretty flat to me. Why were you talking about tailing off, elbows and kinks if all you were looking for was less slope to the curve? I think you need to ride more and argue less.


If you think a continuous downwards curve like that illustration is flat, you are confused.
I mentioned tailing off, elbows and kinks because others have referred to them, it's me who argues they don't exist on the curve.
If I look at my CP curve a 5% increase in power results in a 50% decrease in TTE. That feels very much like a threshold I shouldn't go over if I'm trying to complete a 1 hr effort.
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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Trev is a troll, he has many threads on this subject.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Andrew Coggan wrote:
You do understand that that is just a schematic diagram that I drew to illustrate the point, don't you? (Actually, apparently not.)


The point is you put up a graph which does not show what you claim it does. Your so called small increase in FTP is approximately 25 watts, 9%, that is not small.

My comments are about the graph, it is of no consequence that you now claim you just made it up. One must quesstion how many graphs or charts you post which you just made up.

Are you now claiming you drew a diagram which is inaccurate?
Trev, you really must try harder not to look like a fool.

Squeeze those two illustrative PD lines closer together, so that for example the difference in power at the same point in the illustration was say just a handful of watts (plausible enough for you?). Then draw the horizontal line again to see the impact on TTE. A 1% change in power in that region of the curve will still result in ~10% change (give or take) in TTE at the original power.

Even though Andy's diagram was for illustrative purposes, you suggested 25W was not realistic/plausible.

I personally have two PD curves that are 78W different at 60-minutes.

At the same absolute power at which the lower PD curve is at 60-min, the upper PD curve is at 3.5 hours.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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The illustration shows that if you improve TTE / time to fatigue you also improve power around the 60 minute mark. So if you look at my original post in this thread, the diagram confirms what I was saying. If you increase TTE from say, 40 minutes to 70 minutes, your power at 40 minutes will have also increased.

I pointed out that the approx 25 watt increase, an approx 9% increase in power is not small so the illustration is misleading. No one disputes that an increase in power causes a shorter time to fatigue, my point is that you can increase power almost anywhere on the power duration curve and get the same sort of reduction in duration and that there is nothing special about approximately 60 minutes.





AlexS wrote:
Trev wrote:
Andrew Coggan wrote:
You do understand that that is just a schematic diagram that I drew to illustrate the point, don't you? (Actually, apparently not.)


The point is you put up a graph which does not show what you claim it does. Your so called small increase in FTP is approximately 25 watts, 9%, that is not small.

My comments are about the graph, it is of no consequence that you now claim you just made it up. One must quesstion how many graphs or charts you post which you just made up.

Are you now claiming you drew a diagram which is inaccurate?

Trev, you really must try harder not to look like a fool.

Squeeze those two illustrative PD lines closer together, so that for example the difference in power at the same point in the illustration was say just a handful of watts (plausible enough for you?). Then draw the horizontal line again to see the impact on TTE. A 1% change in power in that region of the curve will still result in ~10% change (give or take) in TTE at the original power.

Even though Andy's diagram was for illustrative purposes, you suggested 25W was not realistic/plausible.

I personally have two PD curves that are 78W different at 60-minutes.

At the same absolute power at which the lower PD curve is at 60-min, the upper PD curve is at 3.5 hours.
Last edited by: Trev: Jun 10, 18 0:51
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
my point is that you can increase power almost anywhere on the power duration curve and get the same sort of reduction in duration

Strictly speaking, this is not true. At short durations, the change in Y is greater than the change in X.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Trev wrote:
my point is that you can increase power almost anywhere on the power duration curve and get the same sort of reduction in duration


Strictly speaking, this is not true. At short durations, the change in Y is greater than the change in X.


Yes, agreed, I should have made it more clear, instead of using the word ' almost'. Out of interest what durations would you class as ' short ' ? Up to 10 minutes? 5 minutes? Or even shorter?


Last edited by: Trev: Jun 10, 18 12:19
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
what durations would you class as ' short ' ? Up to 10 minutes? 5 minutes? Or even shorter?

It was a statement of fact, not an opinion:


Last edited by: Andrew Coggan: Jun 10, 18 5:30
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Trev wrote:
what durations would you class as ' short ' ? Up to 10 minutes? 5 minutes? Or even shorter?

It was a statement of fact, not an opinion:



Thanks for posting the chart. On my small iPad it isn't easy to see exactly the time line. I assume that is a chart using actual data and not just an illustration.

Would you agree that chart shows short durations, in the context of this discussion, would be anything under approximately 3 minutes?
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
If I look at my CP curve a 5% increase in power results in a 50% decrease in TTE. That feels very much like a threshold I shouldn't go over if I'm trying to complete a 1 hr effort.
We can make similar statements about other durations, though. If I add 5% to my 20 minute power, I see an approx 50% decrease in TTE. If I add 5% to my 100 minute power, it gives an approx 50% decrease in TTE. So 60 minutes doesn't differ from many other points on the PD curve in this respect.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Yes, log-normalization of the data (i.e., using percentages) is one way dealing with the non-linear nature of the exercise intensity-duration relationship, e.g.:

https://www.ncbi.nlm.nih.gov/m/pubmed/18379223/

https://www.ncbi.nlm.nih.gov/m/pubmed/15809572/
Last edited by: Andrew Coggan: Jun 10, 18 10:10
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
If I look at my CP curve a 5% increase in power results in a 50% decrease in TTE. That feels very much like a threshold I shouldn't go over if I'm trying to complete a 1 hr effort.

We can make similar statements about other durations, though. If I add 5% to my 20 minute power, I see an approx 50% decrease in TTE. If I add 5% to my 100 minute power, it gives an approx 50% decrease in TTE. So 60 minutes doesn't differ from many other points on the PD curve in this respect.
OK. My snarky comment would be: so what? For better or worse most people have become accustomed to using roughly 60 min (FTP). Seems to work well for most people for tracking workload, setting training bands, general communications etc. I suppose one could define some other time period for standardized power measurements but at this time what would be the point?
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
OK. My snarky comment would be: so what? For better or worse most people have become accustomed to using roughly 60 min (FTP). Seems to work well for most people for tracking workload, setting training bands, general communications etc. I suppose one could define some other time period for standardized power measurements but at this time what would be the point?
First of all, I'm not arguing against the idea of using 60 minute power as a reference for setting training zones. That is absolutely fine as a concept, and Olbrecht, for example, put forward a similar idea many years ago. What I'm arguing against is the claim that there is some sort of "threshold", a feature in the power duration curve, that is unique to the region around 60 minutes. When we press the people making this claim for a sufficiently rigorous definition to enable the claim to be tested, by seeing if the region around 60 minutes satisfies their definition, while other regions do not, they will not provide a sufficiently rigorous definition to allow that. The definition you gave, of a 5% increase in power giving rise to a 50% reduction in TTE, is a sufficiently rigorous definition, but the 60 minute region is not unique in having that characteristic.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
OK. My snarky comment would be: so what? For better or worse most people have become accustomed to using roughly 60 min (FTP). Seems to work well for most people for tracking workload, setting training bands, general communications etc. I suppose one could define some other time period for standardized power measurements but at this time what would be the point?

First of all, I'm not arguing against the idea of using 60 minute power as a reference for setting training zones. That is absolutely fine as a concept, and Olbrecht, for example, put forward a similar idea many years ago. What I'm arguing against is the claim that there is some sort of "threshold", a feature in the power duration curve, that is unique to the region around 60 minutes.
Whether or not its unique there is definitely a threshold in power in the 40-70 min range where the power is defined as FTP. If you used some other time period in that vicinity, e.g. 20 min there is also a threshold that is very close to FTP.

It's not clear why it needs to be unique or precisely pinned down. FTP is always somewhat 'fuzzy' depending on training load, fatigue and a host of other factors. I think of it more as a band of power rather than a precise number.
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
Whether or not its unique there is definitely a threshold in power in the 40-70 min range where the power is defined as FTP. If you used some other time period in that vicinity, e.g. 20 min there is also a threshold that is very close to FTP.

It's not clear why it needs to be unique or precisely pinned down. FTP is always somewhat 'fuzzy' depending on training load, fatigue and a host of other factors. I think of it more as a band of power rather than a precise number.
But you're talking there about two different "threshold" values, one for the ~60 minute region, and one for the ~20 minute region. Basically, all you're saying is that for a given duration, there is a max power you can sustain for that duration, and if you try to exceed that power, you'll reach exhaustion sooner. That is totally true, nobody would disagree with that.

What isn't clear to me is why we can't just talk about x minute power, and what value is added to training by describing it as "FTP" and insisting that there is something unique about the 60 minute region that differentiates the shape of the power duration curve in that region from all other regions. That isn't your claim, so that isn't a criticism of anything you said.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
Whether or not its unique there is definitely a threshold in power in the 40-70 min range where the power is defined as FTP. If you used some other time period in that vicinity, e.g. 20 min there is also a threshold that is very close to FTP.

It's not clear why it needs to be unique or precisely pinned down. FTP is always somewhat 'fuzzy' depending on training load, fatigue and a host of other factors. I think of it more as a band of power rather than a precise number.

But you're talking there about two different "threshold" values, one for the ~60 minute region, and one for the ~20 minute region. Basically, all you're saying is that for a given duration, there is a max power you can sustain for that duration, and if you try to exceed that power, you'll reach exhaustion sooner. That is totally true, nobody would disagree with that.

What isn't clear to me is why we can't just talk about x minute power, and what value is added to training by describing it as "FTP" and insisting that there is something unique about the 60 minute region that differentiates the shape of the power duration curve in that region from all other regions. That isn't your claim, so that isn't a criticism of anything you said.
I think you could possibly make that argument where the power curve is essentially flat or linear with a small slope. That's not the case for short durations (i.e. under 20 min). Going beyond 60 min isn't particularly useful for most people as they don't very often do max efforts at those durations so 60 min seems a good number to settle on.

I don't see any advantage in everyone using a different x for defining their threshold. FTP seems a useful concept for many and simplifies communications. Despite some feeling FTP is dead it seems fairly ubiquitous (embedded in millions of Garmins) and I'm not sure your concerns with the definition resonate with very many riders. At some point inertia makes it difficult to change systems even if they aren't perfect. Once you've got everyone weaned off FTP you can start working on the Imperial measurement system :)
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
I don't see any advantage in everyone using a different x for defining their threshold. FTP seems a useful concept for many and simplifies communications.
Again, I'm not arguing that. As I said, picking a duration and using power for that duration as a reference is fine. We could call it something like, say, "60 minute power", maybe call it P60 if we want to shorten it to 3 characters. What does FTP add that isn't provided by using P60?
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
I don't see any advantage in everyone using a different x for defining their threshold. FTP seems a useful concept for many and simplifies communications.

Again, I'm not arguing that. As I said, picking a duration and using power for that duration as a reference is fine. We could call it something like, say, "60 minute power", maybe call it P60 if we want to shorten it to 3 characters. What does FTP add that isn't provided by using P60?
Everyone (almost) has adopted and understands FTP. There's no value in changing now. What would be the point?
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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gregf83 wrote:
Everyone (almost) has adopted and understands FTP. There's no value in changing now. What would be the point?
Until not that long ago (basically when WKO4 shipped), most people who had adopted FTP were regarding it as interchangeable with 60 minute power or 25 mile / 40km TT power. Threads like this one didn't exist at that time, as there was no need for discussion of these issues when FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP).

What changed with WKO4 shipping is that FTP was no longer equivalent to 60 minute power or 25 mile / 40km TT power. Now it has a floating duration, it might be your 40 minute power one day, then you feed it another file and now it's your 70 minute power. To be able to choose this point, it is claimed that there is a characteristic in the power duration curve that is unique to where FTP is located. Some people, and I am one of them, dispute that such a point exists in that region, with a characteristic that is unique to that region and doesn't exist outside that region. When challenged to provide a definition that would allow their claim to be tested, they will not provide one.

Re your question of what would be the point of using 60 minute power or 25 mile / 40km TT power as a metric instead of the WKO4 concept of a floating pair of numbers, (duration, power) - for me, it would better match my actual performance, as I don't really want to have to wonder whether xW for y mins represents better or worse performance than aW for b mins, and I've seen my WKO4 mFTP move significantly in the opposite direction to my actual performance, even when the duration it has picked hasn't changed significantly.

When you look at the paper that was published fairly recently that appears to support the concept of FTP, it's actually using FTP as a synonym for 60 minute power, not the floating (duration, power) concept of WKO4. So there is an example of a group that is still in fact using P60 rather than FTP, even though they described P60 as FTP.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Revisionist history: FTP has never been defined as exactly 60 min power, at least not by anybody who really knew what they were talking about.

If anyone reading this has ever believed otherwise, they should blame the source that misled them (or their own reading comprehension).
Last edited by: Andrew Coggan: Jun 10, 18 16:14
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
What I'm arguing against is the claim that there is some sort of "threshold", a feature in the power duration curve, that is unique to the region around 60 minutes.

Clearly you haven't been paying attention to anything that has been said in this thread (or the similar one on wattage).

The use of the term "threshold" refers to the physiological responses, which dictate the shape of the power-duration relationship.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
If I look at my CP curve a 5% increase in power results in a 50% decrease in TTE. That feels very much like a threshold I shouldn't go over if I'm trying to complete a 1 hr effort.

We can make similar statements about other durations, though. If I add 5% to my 20 minute power, I see an approx 50% decrease in TTE. If I add 5% to my 100 minute power, it gives an approx 50% decrease in TTE. So 60 minutes doesn't differ from many other points on the PD curve in this respect.

You need to stop thinking of threshold in terms of the slope along a PD curve.

Why? Because the PD curve is an integral of the energy supply from all metabolic pathways (sustainable and non-sustainable), not just the sustainable metabolism which supports power at threshold.

At sub-threshold power we are getting along fine with energy demand supplied wholly via sustainable (i.e. aerobic) metabolic processes.

As power demand increases (and TTE reduces), at some point the non-sustainable energy sources begin to supplement the sustainable sources to a not insignificant degree.

At 20-minutes it's reasonably significant, in the vicinity of 5% of total energy demand (but there is obviously individual variance). At 4-minutes it's in the vicinity of 25% (or more) of the total energy demand.

What you describe as a feature of a PD curve is that hard to recognise difference in slope as the non-sustainable energy contribution drops from minor but significant, to negligible.

Just because the slope doesn't display an apparent significant change in that duration range does not mean threshold can be just anywhere in that range.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
Everyone (almost) has adopted and understands FTP. There's no value in changing now. What would be the point?

Until not that long ago (basically when WKO4 shipped), most people who had adopted FTP were regarding it as interchangeable with 60 minute power or 25 mile / 40km TT power. Threads like this one didn't exist at that time, as there was no need for discussion of these issues when FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP).

What changed with WKO4 shipping is that FTP was no longer equivalent to 60 minute power or 25 mile / 40km TT power. Now it has a floating duration, it might be your 40 minute power one day, then you feed it another file and now it's your 70 minute power. To be able to choose this point, it is claimed that there is a characteristic in the power duration curve that is unique to where FTP is located. Some people, and I am one of them, dispute that such a point exists in that region, with a characteristic that is unique to that region and doesn't exist outside that region. When challenged to provide a definition that would allow their claim to be tested, they will not provide one.

Re your question of what would be the point of using 60 minute power or 25 mile / 40km TT power as a metric instead of the WKO4 concept of a floating pair of numbers, (duration, power) - for me, it would better match my actual performance, as I don't really want to have to wonder whether xW for y mins represents better or worse performance than aW for b mins, and I've seen my WKO4 mFTP move significantly in the opposite direction to my actual performance, even when the duration it has picked hasn't changed significantly.

When you look at the paper that was published fairly recently that appears to support the concept of FTP, it's actually using FTP as a synonym for 60 minute power, not the floating (duration, power) concept of WKO4. So there is an example of a group that is still in fact using P60 rather than FTP, even though they described P60 as FTP.
I understand. Your beef is really with WKO4. I just use Golden Cheetah and Strava and have a reasonable idea what my FTP (old definition) is although I no longer test in any structured way.

Given you're an experienced cyclist/racer, does it really matter what WKO4 says your FTP is? Do you use it for more than a general guide when racing?
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Re: TTE / FTP Question [gregf83] [ In reply to ]
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Reality is too complex for some people.
Last edited by: Andrew Coggan: Jun 10, 18 18:46
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
gregf83 wrote:
Everyone (almost) has adopted and understands FTP. There's no value in changing now. What would be the point?

Until not that long ago (basically when WKO4 shipped), most people who had adopted FTP were regarding it as interchangeable with 60 minute power or 25 mile / 40km TT power. Threads like this one didn't exist at that time, as there was no need for discussion of these issues when FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP).

What changed with WKO4 shipping is that FTP was no longer equivalent to 60 minute power or 25 mile / 40km TT power. Now it has a floating duration, it might be your 40 minute power one day, then you feed it another file and now it's your 70 minute power.
40km TT power or maximum power sustainable for 60-min have always been ways to estimate FTP. So has performance of regular long intervals, so has the use of the Critical Power model. Various ways to estimate. Never has it been defined as being exactly 60-min.

Don't confuse FTP with ways of estimating it.

Steve Irwin wrote:
Now it has a floating duration, it might be your 40 minute power one day, then you feed it another file and now it's your 70 minute power. To be able to choose this point, it is claimed that there is a characteristic in the power duration curve that is unique to where FTP is located. Some people, and I am one of them, dispute that such a point exists in that region, with a characteristic that is unique to that region and doesn't exist outside that region.
Neither has anyone suggested FTP is defined as a specific point along a curve.

The use of power duration models (e.g. "classic" Critical Power) is another way to estimate FTP, as is the WKO4 PD model.

In the first instance, CP is one of two parameters which describes the PD curve (in this case a hyperbola), the other being W'. Now you wouldn't consider CP to be a point along the curve. It's a model parameter.

In the latter instance the modelled FTP (mFTP) is one of three parameters of the WKO4 PD model (the others being FRC and Pmax). Like CP, mFTP is also a model parameter.

http://www.cyclecoach.com
http://www.aerocoach.com.au
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Steve Irwin wrote:
What I'm arguing against is the claim that there is some sort of "threshold", a feature in the power duration curve, that is unique to the region around 60 minutes.

Clearly you haven't been paying attention to anything that has been said in this thread (or the similar one on wattage).

The use of the term "threshold" refers to the physiological responses, which dictate the shape of the power-duration relationship.



Then why doesn't the shape of the power duration curve show a threshold?

If the physiological responses dictate the shape of the power duration relationship then the shape of the curve must also be dictated by those responses. Therefore it must be possible to define threshold as a shape on the curve or give a clear definition of percentages or ratios or something unique and specific which identifies the threshold, eg, a rate of decline over the first few minutes and power at later durations. Once FTP has been given a specific number it then has a specific point on the power duration curve. Obviously everyone's curve will be different and the same persons curve can change, but there must be a clear definition of what identifies threshold on the power duration curve.
Last edited by: Trev: Jun 11, 18 6:04
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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"Neither has anyone suggested FTP is defined as a specific point along a curve. "


The original definition was,

"FTP is the highest power that a rider can maintain in a quasi-steady state without fatiguing for approximately one hour. When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer".

The original area on the power duration curve where FTP was claimed to be found was approximately 60 minutes duration. Once you give FTP a number e.g. 300 watts, then that number only occurs at one specific point on the curve.

mFTP is clearly marked on the curve as a specific power number and a specific duration. Time to exhaustion is a specific power number and a specific duration.

So you can't claim FTP has not been claimed or defined as a specific point on the power duration curve.


The original definition didn't give a specific point along the curve but a vague approximate area along the curve, at approximately 60 minutes. This was then stretched to be even more vague and unspecific as somewhere along the curve between 30 and 70 minutes.
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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"Don't confuse FTP with ways of estimating it. "

People, and certainly not Steve, don't confuse FTP with ways of estimating it. It is the lack of a clear precise vigorous definition which forces people to look at ways of estimating it, e.g., when people do studies and use power over 60 minutes as FTP or take 95% of 20 minute power.

You only have Andrew to blame for the lack of a proper definition. And it's time people stopped hiding behind vague imprecise definitions and pathetic statements like " don't confuse FTP with ways of estimating it".
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:

"Neither has anyone suggested FTP is defined as a specific point along a curve. "


The original definition was,

"FTP is the highest power that a rider can maintain in a quasi-steady state without fatiguing for approximately one hour.

http://www.dictionary.com/browse/a

a

[uh; when stressed ey]

indefinite article

a certain; a particular

http://www.dictionary.com/browse/approximately

approximate

[adjective uh-prok-suh-mit; verb uh-prok-suh-meyt]

verb (used with object), ap·prox·i·mat·ed, ap·prox·i·mat·ing.

to come near to; approach closely to:

Related forms

ap·prox·i·mate·ly, adverb
Last edited by: Andrew Coggan: Jun 11, 18 5:46
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
"Don't confuse FTP with ways of estimating it. "


People, and certainly not Steve, don't confuse FTP with ways of estimating it.


Irwin's very own words disprove your statement:

"FTP was no longer equivalent to 60 minute power or 25 mile / 40km TT power"

FTP was never equivalent to 60 min/25 mi/40 km TT power. Hence the PPP:

~40 km (or ~1 h) power is to FTP as s is to σ
Last edited by: Andrew Coggan: Jun 11, 18 5:45
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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AlexS wrote:
40km TT power or maximum power sustainable for 60-min have always been ways to estimate FTP. So has performance of regular long intervals, so has the use of the Critical Power model. Various ways to estimate. Never has it been defined as being exactly 60-min.

Don't confuse FTP with ways of estimating it.
Right there, in the very text you quoted, I said "FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP)". If the best way to estimate it was 60 minute power then it did mean essentially the same thing as 60 minute power, as nothing else provided a better way to estimate it. If you wanted to make use of FTP in your training, then you needed to quantify it, so if the best way to estimate it was 60 minute power and you knew your 60 minute power, why would you use any other figure as your FTP?

AlexS wrote:
Neither has anyone suggested FTP is defined as a specific point along a curve.
What is your definition of FTP?
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Andrew Coggan wrote:
Steve Irwin wrote:
What I'm arguing against is the claim that there is some sort of "threshold", a feature in the power duration curve, that is unique to the region around 60 minutes.

Clearly you haven't been paying attention to anything that has been said in this thread (or the similar one on wattage).

The use of the term "threshold" refers to the physiological responses, which dictate the shape of the power-duration relationship.


Then why doesn't the shape of the power duration curve show a threshold?


Because the physiological responses dictate a ceiling or plateau in sustainable* power, above which you can continue only by supplementing this "baseline" by drawing upon non-sustainable reserves.


If not for such reserves, "threshold" would be the maximum power that could be generated for any length of time.

*Recognizing, of course, that even BMR can only be maintained for a finite period of time, which is only made to seem interminable by Trev's constant trolling.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
I said "FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP)". If the best way to estimate it was 60 minute power then it did mean essentially the same thing as 60 minute power

See the PPP in red above.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Irwin's very own words disprove your statement:

"FTP was no longer equivalent to 60 minute power or 25 mile / 40km TT power"

FTP was never equivalent to 60 min/25 mi/40 km TT power. Hence the PPP:

~40 km (or ~1 h) power is to FTP as s is to σ
From a dictionary:
equivalent - something that has the same amount, value, purpose, qualities, etc. as something else

I'd say that if 60 minute power was the best way to estimate FTP, then they were equivalent in the above sense.
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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The bolded part below is why they are not equivalent. FTP is a concept; 60 min/25 mi/40 km TT power is just a way of numerically estimating its value.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

e·quiv·a·lent

əˈkwiv(ə)lənt/Submit

adjective

1.

equal in [ . . ] meaning, etc.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
The bolded part below is why they are not equivalent. FTP is a concept; 60 min/25 mi/40 km TT power is just a way of numerically estimating its value.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

e·quiv·a·lent

əˈkwiv(ə)lənt/Submit

adjective

1.

equal in [ . . ] meaning, etc.

Give a clear definition of FTP. Not the usual vague rubbish. As it is the definition of your unproven concept is so vague as to be utterly useless, this is why people are forced to use various estimates of FTP, even when they are doing scientific research.

e.g., "When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer."

This statement, apart from being extremely vague, is misleading, because it sets FTP apart as if it is the only power at which this occurs. You could say the same for any duration on the power duration curve beyond the first few minutes.

As to ' approximately ' 60 minutes, please explain what you mean by approximately 60 minutes. Do you agree 55 to 65 minutes is approximately 60 minutes? Do you also agree 30 to 70 minutes is approximately 60 minutes? How far do you want to stretch approximately, as far as 15 minutes to 90 minutes? Please give a clear definition of how far you think it is acceptable to stretch approximately 60 minutes. Most rational people would say approximately would be within +\- 10%, but you seem to think it should be +\- 50% which is ludicrous.
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
Give a clear definition of FTP. Not the usual vague rubbish.

Well, since you don't like the original definition, you could say that it is a power that can be sustained for a very long time without fatigue, and is an inherent characteristic of the aerobic energy supply system. Alternatively, you could say that it is the greatest metabolic rate that results in entirely-oxidative energy provision. You might even say that it is is an integral feature of integrative biological exercise performance.

Happy now?
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Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
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Steve Irwin wrote:
AlexS wrote:
40km TT power or maximum power sustainable for 60-min have always been
ways to estimate FTP. So has performance of regular long intervals, so has the use of the Critical Power model. Various ways to estimate. Never has it been defined as being exactly 60-min.

Don't confuse FTP with ways of estimating it.

Right there, in the very text you quoted, I said "FTP essentially meant the same thing as P60 (60 minute power was described as the best way to estimate FTP)". If the best way to estimate it was 60 minute power then it did mean essentially the same thing as 60 minute power, as nothing else provided a better way to estimate it. If you wanted to make use of FTP in your training, then you needed to quantify it, so if the best way to estimate it was 60 minute power and you knew your 60 minute power, why would you use any other figure as your FTP?

Well, yes, the best indicator of performance capability is performance and a TT-like effort of about an hour would be darn good. But there are few reasons why we might consider alternative or supplemental methods. For example:
  • If you are not fortunate enough to have roads handy which safely permit an uninterrupted maximal effort of about an hour, e.g. a ~40kmTT, then it might be better to consider alternative options for estimating FTP. e.g. in Australia there are only a few TT courses of ~40km which are used.

  • You may be able to ride for about an hour uninterrupted but the terrain or course you have available is not conducive to executing a suitable quasi-steady state effort. Highly variable gradient, or technical elements which might impact average power and require the use of and recharge of non-sustainable energy metabolism (and so we might use an alternative indicator of aerobic metabolic capability in the form of Normalized Power).

  • To avoid being reliant on a single data point. Hence use of suitable alternative methods can be helpful to provide some validation. Of course if you are in good health on the day, are confident the power data is accurate and you gave it best effort with nothing which would have unduly impacted performance, then great, you have an excellent data point!
    But what if you embarked on some training which involved doing some longer intervals near that threshold value but you consistently couldn't do them, or they were too easy? Hence an alternative estimation method such as what you can repeatedly do in longer interval efforts is also a good way to estimate/validate FTP.

  • Some people might be better off using one or more alternative methods due to the nature of the racing they do, or the goals they are focused on, or the environment in which they are training.

  • Some might not be ready to do any testing due to their health status, or being in poor condition such that undertaking hard efforts may be unwise. In such a case they might be better to use an experience-led guesstimate for a while (e.g. if they want to have reasonable ballpark estimate of things like TSS) until they are in better condition to do some tests.

We have multiple means to estimate FTP, some may be more readily useful or practical to implement for a particular individual's circumstances.

Steve Irwin wrote:
AlexS wrote:
Neither has anyone suggested FTP is defined as a specific point along a curve.

What is your definition of FTP?

The same as the original definition. I wrote about it here:
https://wattmatters.blog/.../2018/6/5/wtf-is-ftp



http://www.cyclecoach.com
http://www.aerocoach.com.au
Last edited by: AlexS: Jun 11, 18 15:09
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
~40 km (or ~1 h) power is to FTP as s is to σ
I'm am *very* reluctant to jump into this thread, but now that Andy is speaking my language I can't resist :-).

In the case of s and \sigma, we have a very clear definition of what \sigma is. It is the standard deviation of the population of interest - I can give you an exact formula for it that hinges on knowing the population distribution. Sure, I typically can't know the population distribution in real world applications, which means I can't compute \sigma exactly, but the thought experiment of how I would compute \sigma if I had infinite amounts of data is important and tells me how to estimate \sigma.

I see Steve's question as (approximately) this: suppose we knew the whole population of MMP curves for one particular cyclist. E.g., suppose we knew the distribution of MMP across all possible days (to the extent that it varies, which it does). How could we compute FTP from this information? It seems like you have to know the answer to that question before you go trying to estimate FTP. Is it possible to compute FTP from this information? If not, what additional information would we need?
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Re: TTE / FTP Question [lanierb] [ In reply to ]
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If logic is your language, then yes, I am speaking it. :) I would argue, though, that you are carrying the analogy a step too far.

Sigma is a statistical concept, and as such, can be expressed as a formula even if the data are rarely available to solve for it.

FTP, on the other hand, is a physiological concept, and as such exists apart from any mathematics used to estimate it.

ETA: The renal threshold for glucose is another physiological concept comparable to FTP. Similarly, over in the field of climatology man-made global warming is a concept that exists independent of any math used to quantify it.
Last edited by: Andrew Coggan: Jun 11, 18 16:57
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
The bolded part below is why they are not equivalent. FTP is a concept; 60 min/25 mi/40 km TT power is just a way of numerically estimating its value.

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

e·quiv·a·lent

əˈkwiv(ə)lənt/Submit

adjective

1.

equal in [ . . ] meaning, etc.
That is as useful as if I were to criticise your use of the word 'bolded' by saying that you didn't make the words fearless before danger.

Your training zones used to be defined as %s of FTP, but I see that in 2016 you were instead defining them as %s of power at LT:
https://www.trainingpeaks.com/...wer-training-levels/
How would you describe the relationship between FTP and power at LT? Is the best estimate of FTP also the best estimate of power at LT?
Quote Reply
Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
Quote | Reply
Steve Irwin wrote:
Your training zones used to be defined as %s of FTP, but I see that in 2016 you were instead defining them as %s of power at LT:
https://www.trainingpeaks.com/...wer-training-levels/

TP may have posted that web page in 2016, but they lifted the text from the chapter that I wrote for USA Cycling back in 2003:

Coggan AR. Training and racing using a power meter: an introduction. In: Level II Coaching Manual. Colorado Springs, CO: USA Cycling, 2003, pp. 123-145.

Hunt around the web, and you should be able to find a copy. Once again, though, the giveaway that I didn't have control over what's on the TP website is the way that they have incorrectly listed my name (use of "Dr." and "Ph.D." is redundant).

EDIT: Here is an electronic copy:

http://www.ipmultisport.com/...ggan_Power_Meter.pdf

Steve Irwin wrote:
How would you describe the relationship between FTP and power at LT? Is the best estimate of FTP also the best estimate of power at LT?

As I have pointed out numerous times before, people in the field of exercise physiology often use the term lactate threshold (or the acronym LT) to refer to both the general concept and to a specific value obtained using a particular protocol. The chapter was written at around the same time that I started referring to it as FTP, to try to get people to stop confusing themselves by thinking about lab-based lactate measurements. I still tended to use them somewhat interchangeably back then, though, i.e., it is in reference to the concept and not a particular value that "LT" refers to in that chapter.

The above is the long answer. The short answer is, it depends on precisely how LT is defined. If you go by Ed Coyle's criteria (i.e., a 1 mmol/L increase in venous blood lactate above exercise baseline, measured during a discontinuous protocol using 10 min stages), however, the FTP is typically about 5-10% higher (you can work out an exact conversion from his 1991 MSSE paper).
Last edited by: Andrew Coggan: Jun 12, 18 6:53
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:
The original area on the power duration curve where FTP was claimed to be found was approximately 60 minutes duration. Once you give FTP a number e.g. 300 watts, then that number only occurs at one specific point on the curve.

mFTP is clearly marked on the curve as a specific power number and a specific duration. Time to exhaustion is a specific power number and a specific duration.

So you can't claim FTP has not been claimed or defined as a specific point on the power duration curve.

mFTP, one method of estimating FTP via use of a power-duration model, is reported along with an error of estimate, as is TTE. The values are shown on charts already. That you might have looked at a random chart without that displayed is neither here nor there.

You criticise those who describe physiological reality rather than provide a false sense of precision.

No matter what method of threshold power estimation you use (lactate, O2 motnitoring, gas exchange, breathing rates, PD models such as CP or WKO4), the reality is there will be a estimate range within which the "true" value most probably lies. All of them have an associated error. None of them ever know what the "true" value is. But good estimation methods can narrow it down pretty well, and to a precision level that is useful.

It's a physiological reality. So get over it.

http://www.cyclecoach.com
http://www.aerocoach.com.au
Quote Reply
Re: TTE / FTP Question [AlexS] [ In reply to ]
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Trev.
Thick as a post.

Everybody else.
Amazingly tolerant and patient of somebody that just doesn't get it.

Trev mate, you really need to learn a bit more about the underlying physiology.
All will be clear then.

This is actually a good thread because everybody is going to great pains to try and educate somebody that knows naught about the subject and in doing so, creating some of the most accessible to layman descriptions and information found anywhere.
Quote Reply
Re: TTE / FTP Question [AlexS] [ In reply to ]
Quote | Reply
AlexS wrote:
is reported along with an error of estimate, as is TTE. The values are shown on charts already. That you might have looked at a random chart without that displayed is neither here nor there.

How does the error of estimate work, actually?
Is it just a description of how well the model (i.e. the calculated FTP and FRC) fits to the MMP-curve, or is more to it?
Quote Reply
Re: TTE / FTP Question [asgagd] [ In reply to ]
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Just picking a link at random, see point 3:

http://stat.ethz.ch/~stahel/courses/cheming/nlreg10E.pdf
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
Quote | Reply
Andrew Coggan wrote:
If you go by Ed Coyle's criteria (i.e., a 1 mmol/L increase in venous blood lactate above exercise baseline, measured during a discontinuous protocol using 10 min stages), however, the FTP is typically about 5-10% higher (you can work out an exact conversion from his 1991 MSSE paper).
So how does FTP relate to the anaerobic threshold, which this paper found to be associated with a TTE of 60 minutes?
https://www.ncbi.nlm.nih.gov/pubmed/2242751
Quote Reply
Re: TTE / FTP Question [Steve Irwin] [ In reply to ]
Quote | Reply
Steve Irwin wrote:
Andrew Coggan wrote:
If you go by Ed Coyle's criteria (i.e., a 1 mmol/L increase in venous blood lactate above exercise baseline, measured during a discontinuous protocol using 10 min stages), however, the FTP is typically about 5-10% higher (you can work out an exact conversion from his 1991 MSSE paper).
So how does FTP relate to the anaerobic threshold, which this paper found to be associated with a TTE of 60 minutes?
https://www.ncbi.nlm.nih.gov/pubmed/2242751

On average, FTP, "anaerobic" (i.e., ventilatory) threshold, MLSS, IAT, the iEMG threshold, the NIRS breakpoint, etc., etc., etc., all correspond to (essentially) the same exercise intensity. In fact, FTP is a blanket concept that explicitly recognizes this fact.

However, whether you see exact correspondence in any given individual, or even in a study of a small number of subjects, will depend in part upon both the exact methods used as well as random variability.

The above is so well-established by the existing literature that additional studies simply comparing the various "thresholds" are, IMO, a waste of time. To further advance the field, investigators should be focusing on why any small discrepancies might exist, i.e., are they entirely due to random factors, or are their some underlying, cause-and-effect physiological relationships?

Note that some inroads into such questions have already been made, e.g., two decades ago it had already been established that interval training tends to have a bigger effect on VT than LT, whereas the opposite is true with steady-state endurance training.

Unfortunately, many younger scientists seem to be unaware of the numerous previous studies in this area, which really developed starting in the late 1970s. As a result, they spin their wheels repeating experiments that have already been performed, or designing studies the results of which are entirely predictable.

Note that the final comment also applies to this study:

https://www.ncbi.nlm.nih.gov/pubmed/29203319

That is, it is already well-established that the range of test durations used as well as the formula chosen has a significant impact on the calculated CP (and W'). Thus, while it is handy to have all of the comparisons in one place, and the paper may be publishable for that fact alone, at the end of the day nothing new has really been learned as a result of the authors' (and subjects') efforts. Their time and energy would have been better spent pursuing a more important/novel/unanaswered question.
Last edited by: Andrew Coggan: Jun 13, 18 6:45
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:


It is me who is pointing out that if there is a power threshold it should show up on the power duration curve as a flat area. It is the lack of a clear flat threshold showing on the curve which is one reason I question FTP.


The PD curve is a strictly decreasing monotonic curve. Therefore, FTP/CP cannot be identified as a point along the PD curve. There is no basis for choosing one point over another unless you start considering first derivatives. Besides, since each point on the curve is derived on different days, albeit different weeks or months even, one can't really argue that the rate of change of the PD curve aligns with some physiological phenomenon.

One can use the CP/W' model to yield a consistent and repeatable measure for threshold power. When you consider the amount of work available above threshold (W'), this work can be consumed above threshold, independent of intensity. (Note that in Xert we further constrain the ability to use up this available work across all durations. This is our concept of MPA. For example, you can use up more W' at 20 minute power than at 5 minute power. This is a main difference in how Xert works vs. how CP/W' works.)

This principle does not hold true when you consider lower values for threshold. Let's look at some PD curves to understand why:

https://www.xertonline.com/calculator?power_0=315&duration_0=1200&power_1=359&duration_1=300&power_2=1000&duration_2=1&action=calculate


High Intensity Energy is analogous to W'. The calculation yields an HIE of 18.6kJ and an FTP of 300W.


https://www.xertonline.com/calculator?power_0=315&duration_0=1200&power_1=364.4&duration_1=300&power_2=1000&duration_2=1&action=calculate


This yields an HIE of 21kJ and an FTP of 298W. We kept 20 minute power and 1s power the same for convenience.


So for a 2W difference in FTP, we see a 2.4kJ increase in W'/HIE which would then imply a 5.4W increase in 5 minute power. If indeed FTP was 2W lower then the additional W'/HIE would then be available for use at intensities above FTP. If this is not the case and 5 minute power is 359W, then FTP must be 300W and not 298W.


This example is a simplification of how Xert does this and how it is able to consistently and precisely measure FTP. It will pick up small variations in FTP that can then be tracked and managed with training.

Armando Mastracci, Founder of Xert, an advanced data analytics and training platform. Blog, Podcasts
Quote Reply
Re: TTE / FTP Question [xert] [ In reply to ]
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xert wrote:
The PD curve is a strictly decreasing monotonic curve. Therefore, FTP/CP cannot be identified as a point along the PD curve. There is no basis for choosing one point over another

You're as bad as Trev. Worse, actually, since you are just here to shill for your product.

As for "choosing one point over another", our bodies certainly seem to think that it can be done, e.g.:

https://www.ncbi.nlm.nih.gov/pubmed/28302463

Given results such as these, only a fool would buy into your argument above (especially the last bit).
Last edited by: Andrew Coggan: Jun 13, 18 10:18
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
Quote | Reply
Andrew Coggan wrote:
xert wrote:
The PD curve is a strictly decreasing monotonic curve. Therefore, FTP/CP cannot be identified as a point along the PD curve. There is no basis for choosing one point over another


You're as bad as Trev. Worse, actually, since you are just here to shill for your product.

As for "choosing one point over another", our bodies certainly seem to think that it can be done, e.g.:

https://www.ncbi.nlm.nih.gov/pubmed/28302463

Given results such as these, only a fool would buy into your argument above (especially the last bit).

Actually, we have more business than we can manage at the moment. Just here to provide folks a unique perspective they may not have heard before.

Going to bow out now and let you folks get back to where you were.

Armando Mastracci, Founder of Xert, an advanced data analytics and training platform. Blog, Podcasts
Quote Reply
Re: TTE / FTP Question [lyrrad] [ In reply to ]
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lyrrad wrote:
Depends how well trained you are and what you have trained.
You can extend time to exhaustion without getting a higher FTP.
You can do it and get a lower FTP.

So as always, it depends.

Just for fun. Who agrees with this?
Quote Reply
Re: TTE / FTP Question [Trev] [ In reply to ]
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Unless you're a Trumpian, you can't really disagree with established facts (lyrrad was referring to the WKO4 model).
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Unless you're a Trumpian, you can't really disagree with established facts (lyrrad was referring to the WKO4 model).

That is the point. The model does not reflect reality.
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
Quote | Reply
Andrew Coggan wrote:
xert wrote:
The PD curve is a strictly decreasing monotonic curve. Therefore, FTP/CP cannot be identified as a point along the PD curve. There is no basis for choosing one point over another


You're as bad as Trev. Worse, actually, since you are just here to shill for your product.

As for "choosing one point over another", our bodies certainly seem to think that it can be done, e.g.:

https://www.ncbi.nlm.nih.gov/pubmed/28302463

Given results such as these, only a fool would buy into your argument above (especially the last bit).


You could ask a timetriallist to perform a 20 minute effort at their 20 minute power and the result would be just as accurate
You could ask a timetriallist to perform a 30 minute effort at their 30 minute power and the result would be just as accurate
You could ask a timetriallist to perform a 40 minute effort at their 40 minute power and the result would be just as accurate
You could ask a timetriallist to perform a 50 minute effort at their 50 minute power and the result would be just as accurate

Whatever duration you ask them to perform, they will pace it well, because almost all racing cyclists worth their salt can do this over any duration in which they have some experience racing at.

Clearly this study in no way validates that there is anything special about MLSS
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
Quote | Reply
Andrew Coggan wrote:
xert wrote:
The PD curve is a strictly decreasing monotonic curve. Therefore, FTP/CP cannot be identified as a point along the PD curve. There is no basis for choosing one point over another
You're as bad as Trev. Worse, actually, since you are just here to shill for your product.
As for "choosing one point over another", our bodies certainly seem to think that it can be done, e.g.: https://www.ncbi.nlm.nih.gov/pubmed/28302463
Given results such as these, only a fool would buy into your argument above (especially the last bit).

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer." This statement, apart from being extremely vague is misleading, because it sets FTP apart as if it is the only power at which this occurs. You could say the same for any duration on the power duration curve beyond the first few minutes.

Why do you perpetuate this threshold power myth?
Last edited by: Trev: Jun 13, 18 15:03
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Re: TTE / FTP Question [Trev] [ In reply to ]
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Trev wrote:

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer." This statement, apart from being extremely vague is misleading, because it sets FTP apart as if it is the only power at which this occurs. You could say the same for any duration on the power duration curve beyond the first few minutes.

Why do you perpetuate this threshold power myth?

When power exceeds any power, fatigue will occur much sooner, whereas power just below that power can be maintained considerably longer.

THis is no more true for LT than it is for any other power, as Armando just implied (and then got insulted for saying it)
Quote Reply
Re: TTE / FTP Question [paull] [ In reply to ]
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Functional Threshold Power is an estimate of the point where we transition from using a mix of carbohydrate and fat to solely using our finite CHO stores. This point is observable when doing ramp tests or the MLSS test.

MLSS is better estimate of this true threshold point than a ramp test although you can observe the transition using lactate, heart rate, NIRS, and expired gas analysis.

Because of the issues with performing ramp tests, where we see a lot of guessing where the inflection point is, if not obvious, and the challenge that performing tests in the lab is not specific to where we actually perform. Plus, the costs and logistics of doing lab test. Also, our physiology changes very rapidly, so, metrics determined from a test have a very short period of usefulness.

So we estimate threshold power from data from the bike in the field. Not just the FTP, but peak power (PMAX), sprint power (PMAX/FRC), track time trial power (FRC), track pursuit power (FRC/FTP) and time trial power (FTP) and long term power (Stamina). To help us plan our training and to teach riders to learn what performance at a given level looks like.

Hamish Ferguson: Cycling Coach
Quote Reply
Re: TTE / FTP Question [lyrrad] [ In reply to ]
Quote | Reply
lyrrad wrote:
Trev.
Thick as a post.

Everybody else.
Amazingly tolerant and patient of somebody that just doesn't get it.

Trev mate, you really need to learn a bit more about the underlying physiology.
All will be clear then.

This is actually a good thread because everybody is going to great pains to try and educate somebody that knows naught about the subject and in doing so, creating some of the most accessible to layman descriptions and information found anywhere.
No one is trying to educate Trev as he's not interested in learning and he has no genuine interest in understanding the topic. That's evident from his persistent repetition of nonsense over many many years.

Any responses to Trev which happen to be educational are done so for the wider audience, not for Trev the Troll.

If anything, Trev's attempts to deliberately sow misunderstanding has consistently backfired.

Trolls are a part of online life unfortunately, so we can either ignore them or use their trolling an an opportunity for learning.

http://www.cyclecoach.com
http://www.aerocoach.com.au
Quote Reply
Re: TTE / FTP Question [Trev] [ In reply to ]
Quote | Reply
Trev wrote:
Why do you perpetuate this threshold power myth?

It's not a myth. There is a power output above which the physiological responses are markedly different from those at even slightly lower intensities. Akin to the renal threshold for glucose spillover in the urine, there is some "splay" or blurring at intensities close to this point, but describing it as a threshold is still a convenient (and widely accepted) paradigm.
Quote Reply
Re: TTE / FTP Question [paull] [ In reply to ]
Quote | Reply
paull wrote:

When power exceeds any power, fatigue will occur much sooner, whereas power just below that power can be maintained considerably longer.

THis is no more true for LT than it is for any other power, as Armando just implied (and then got insulted for saying it)

Armando is as much of a shill as Trev is a troll.

As for your statement, try maintaining a power, say, 100 W above vs. below your FTP, then come back and talk to us.
Quote Reply
Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
Quote | Reply
Andrew Coggan wrote:

Armando is as much of a shill as Trev is a troll.

As for your statement, try maintaining a power, say, 100 W above vs. below your FTP, then come back and talk to us.

You are saying, we have to maintain a power that the rider would NEVER race at to prove your point ? We are only interested in locating where FTP is, and for a rider with a 270w 25 TT power we are looking in a window between their 10TT power at around 290w (cp20) and their 50TT power at around 250w (cp120). What on earth would an effort at around 3 minutes or at around 48 hours give us ? All we are trying to prove here is that 270w is more special than 250w or 290w, because you are saying it is. I maintain that it isn't more special.
Quote Reply
Re: TTE / FTP Question [paull] [ In reply to ]
Quote | Reply
paull wrote:
Andrew Coggan wrote:


Armando is as much of a shill as Trev is a troll.

As for your statement, try maintaining a power, say, 100 W above vs. below your FTP, then come back and talk to us.


You are saying, we have to maintain a power that the rider would NEVER race at to prove your point ? We are only interested in locating where FTP is, and for a rider with a 270w 25 TT power we are looking in a window between their 10TT power at around 290w (cp20) and their 50TT power at around 250w (cp120). What on earth would an effort at around 3 minutes or at around 48 hours give us ? All we are trying to prove here is that 270w is more special than 250w or 290w, because you are saying it is. I maintain that it isn't more special.

Have you ever examined any physiological test data or perhaps read published scientific papers on such things?

I ask because you (and Trev) are claiming the concept of threshold does not exist.

You do so based on the flawed assumption that if it's not obvious just by looking at a PD curve then it doesn't exist (Trev does so because he's a troll). But we've been over this and you still have not got it. Threshold is a physiological phenomenon and the very shape (or lack of shape) of the PD curve in that region is a direct result of the threshold behaviour exhibited by our metabolism.

http://www.cyclecoach.com
http://www.aerocoach.com.au
Last edited by: AlexS: Jun 14, 18 4:51
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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AlexS wrote:


You do so based on the flawed assumption that if it's not obvious just by looking at a PD curve then it doesn't exist (Trev does so because he's a troll). But we've been over this and you still have not got it. Threshold is a physiological phenomenon and the very shape (or lack of shape) of the PD curve in that region is a direct result of the threshold behaviour exhibited by our metabolism.


No, you and AC are claiming that FTP is special because a small increase in power leads to a much shorter TTE, and a small decrease in power leads to a much longer TTE. That has been presented many times as an identifying feature of threshold. However the same assertion is also true of every intensity which we sensibly race at - from well before CP20 right to well beyond CP120. Therefore that assertion should not be used to describe threshold.

i.e. I'm just repeating what Trev said.

Trev wrote:

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer." This statement, apart from being extremely vague is misleading, because it sets FTP apart as if it is the only power at which this occurs. You could say the same for any duration on the power duration curve beyond the first few minutes.

Why do you perpetuate this threshold power myth?
Last edited by: paull: Jun 14, 18 5:09
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Re: TTE / FTP Question [paull] [ In reply to ]
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BTW I don't have a particular affinity to whether a threshold exists or not in terms of lab data - Noakes says no, others say yes. I just think its time people stopped claiming that "FTP" is some kind of special intensity where you can naturally pedal away until the cows come home and its so absolutely noticeable that almost any rider can ride at it on demand.. All intensities have the same features and any rider can ride at 10 pace, 25 pace or 50 pace on demand and get it roughly right every time - they are not likely to get 25 pace more right than 50 pace or 10 pace and AC's quoted study above where he claims this is demonstrated - it absolutely does not demonstrate this whatsoever since they only tested one intensity - other intensities would have given the same finding.
Last edited by: paull: Jun 14, 18 5:34
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Re: TTE / FTP Question [paull] [ In reply to ]
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paull wrote:
Andrew Coggan wrote:

Armando is as much of a shill as Trev is a troll.

As for your statement, try maintaining a power, say, 100 W above vs. below your FTP, then come back and talk to us.

You are saying, we have to maintain a power that the rider would NEVER race at to prove your point ? We are only interested in locating where FTP is, and for a rider with a 270w 25 TT power we are looking in a window between their 10TT power at around 290w (cp20) and their 50TT power at around 250w (cp120). What on earth would an effort at around 3 minutes or at around 48 hours give us ? All we are trying to prove here is that 270w is more special than 250w or 290w, because you are saying it is. I maintain that it isn't more special.

There are none so blind as those who will not see...

To reiterate: "threshold" refers to the physiological responses, which essentially cap your sustainable power at an upper limit. It is the very flatness of the power-duration relationship (where power declines relatively slowly over a wide range of time, i.e., hours) beyond the first few minutes of exercise that results from this fact. The reason for focusing on a particular approximate duration is NOT because of any inflection point in that region, but because power at distinctly shorter (e.g., 20 min) or longer (e.g., 2 h) will be significantly above or below the maximal steady-state intensity.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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So then you must agree that this statement is misleading:

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer."

Because,

"When power exceeds CP20, fatigue will occur much sooner, whereas power just below CP20 can be maintained considerably longer."
"When power exceeds CP40, fatigue will occur much sooner, whereas power just below CP40 can be maintained considerably longer."
"When power exceeds CP60, fatigue will occur much sooner, whereas power just below CP60 can be maintained considerably longer."
"When power exceeds CP120, fatigue will occur much sooner, whereas power just below CP120 can be maintained considerably longer."
Quote Reply
Re: TTE / FTP Question [paull] [ In reply to ]
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paull wrote:
BTW I don't have a particular affinity to whether a threshold exists or not in terms of lab data - Noakes says no, others say yes. I just think its time people stopped claiming that "FTP" is some kind of special intensity where you can naturally pedal away until the cows come home and its so absolutely noticeable that almost any rider can ride at it on demand.. All intensities have the same features and any rider can ride at 10 pace, 25 pace or 50 pace on demand and get it roughly right every time - they are not likely to get 25 pace more right than 50 pace or 10 pace and AC's quoted study above where he claims this is demonstrated - it absolutely does not demonstrate this whatsoever since they only tested one intensity - other intensities would have given the same finding.

Like Trev, you clearly don't understand the signifance of the study I mentioned. It isn't the fact that the subjects held a steady power for 30 min, but the fact that *they honed in on their MLSS while doing so* (and more closely than the CP model).

IOW, perceived exertion indicates that there is indeed a "threshold" intensity, as any experienced athlete (or even untrained subject...just go look up all of the studies of self-regulation of exercise intensity in various training studies) can tell you.

With all that said, there clearly are a few "perceptual idiots" in the world.
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Re: TTE / FTP Question [paull] [ In reply to ]
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paull wrote:
So then you must agree that this statement is misleading:

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer."

Because,

"When power exceeds CP20, fatigue will occur much sooner, whereas power just below CP20 can be maintained considerably longer."
"When power exceeds CP40, fatigue will occur much sooner, whereas power just below CP40 can be maintained considerably longer."
"When power exceeds CP60, fatigue will occur much sooner, whereas power just below CP60 can be maintained considerably longer."
"When power exceeds CP120, fatigue will occur much sooner, whereas power just below CP120 can be maintained considerably longer."

No, it is not misleading, as it is an accurate description of reality.

Again, try sustaining a power measurably above vs. below your FTP for as long as you can, then report back to everyone here.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Lol

Do any of these not reflect reality ?


"When power exceeds CP20, fatigue will occur much sooner, whereas power just below CP20 can be maintained considerably longer."
"When power exceeds CP40, fatigue will occur much sooner, whereas power just below CP40 can be maintained considerably longer."
"When power exceeds CP60, fatigue will occur much sooner, whereas power just below CP60 can be maintained considerably longer."
"When power exceeds CP120, fatigue will occur much sooner, whereas power just below CP120 can be maintained considerably longer."

...

I've ridden enough 10's to know already :) And 15's and 50's and 30's and 5's...

Definitely nothing special about 25TT pace. Anyway, I do believe we are going around in circles. We'll have to agree to differ.
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Re: TTE / FTP Question [paull] [ In reply to ]
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FTP is a power meter based estimation of the point we see in the physiology reflecting concepts such as lactate threshold, oxygenation threshold derived from near-infrared spectroscopy, ventilatory threshold, Critical Power, MLSS and even the Conconi test.

All intensities don't have the same features. Their mix of energy supply will differ and this will influence training and what events a rider should target.

As mentioned before this sort of stuff is very basic for time trials. Where the utility of a well constructed power duration curve comes in handy is for more complex events like track racing, criterium's, road races, undulating time trials and as we saw in the Giro stage races.

This sort of assessment is the start of the process. But then Andy does keep saying "the map is not the territory".

Hamish


paull wrote:
BTW I don't have a particular affinity to whether a threshold exists or not in terms of lab data - Noakes says no, others say yes. I just think its time people stopped claiming that "FTP" is some kind of special intensity where you can naturally pedal away until the cows come home and its so absolutely noticeable that almost any rider can ride at it on demand.. All intensities have the same features and any rider can ride at 10 pace, 25 pace or 50 pace on demand and get it roughly right every time - they are not likely to get 25 pace more right than 50 pace or 10 pace and AC's quoted study above where he claims this is demonstrated - it absolutely does not demonstrate this whatsoever since they only tested one intensity - other intensities would have given the same finding.

Hamish Ferguson: Cycling Coach
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Re: TTE / FTP Question [Kiwicoach] [ In reply to ]
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Kiwicoach wrote:
Functional Threshold Power is an estimate of the point where we transition from using a mix of carbohydrate and fat to solely using our finite CHO stores. This point is observable when doing ramp tests or the MLSS test.

MLSS is better estimate of this true threshold point than a ramp test although you can observe the transition using lactate, heart rate, NIRS, and expired gas analysis.

Because of the issues with performing ramp tests, where we see a lot of guessing where the inflection point is, if not obvious, and the challenge that performing tests in the lab is not specific to where we actually perform. Plus, the costs and logistics of doing lab test. Also, our physiology changes very rapidly, so, metrics determined from a test have a very short period of usefulness.

So we estimate threshold power from data from the bike in the field. Not just the FTP, but peak power (PMAX), sprint power (PMAX/FRC), track time trial power (FRC), track pursuit power (FRC/FTP) and time trial power (FTP) and long term power (Stamina). To help us plan our training and to teach riders to learn what performance at a given level looks like.

A good summary of the most important points. Whilst a headline number is nice to bragg about and/or track progress, the important part is to establish appropriate training levels to elicit the desired physiological adaptations. To me, MLSS seems a very relevant point on the curve to establish.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
paull wrote:
So then you must agree that this statement is misleading:

"When power exceeds FTP, fatigue will occur much sooner, whereas power just below FTP can be maintained considerably longer."

Because,

"When power exceeds CP20, fatigue will occur much sooner, whereas power just below CP20 can be maintained considerably longer."
"When power exceeds CP40, fatigue will occur much sooner, whereas power just below CP40 can be maintained considerably longer."
"When power exceeds CP60, fatigue will occur much sooner, whereas power just below CP60 can be maintained considerably longer."
"When power exceeds CP120, fatigue will occur much sooner, whereas power just below CP120 can be maintained considerably longer."


No, it is not misleading, as it is an accurate description of reality.

Again, try sustaining a power measurably above vs. below your FTP for as long as you can, then report back to everyone here.
Perhaps these guys should head over to an electrical engineering forum and start arguing that silicon diodes don't exhibit a voltage threshold at around .7V. The VI curve of a diode is strikingly similar to the maximum power duration curve of a cyclist.
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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deleted
Last edited by: paull: Jun 14, 18 23:43
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Re: TTE / FTP Question [paull] [ In reply to ]
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paull wrote:
Andrew Coggan wrote:

With all that said, there clearly are a few "perceptual idiots" in the world.


<offending remark in response removed - apology noted>

You do know what Andy was referring to?
That while many are able to self regulate to a threshold intensity pretty well, a minority don’t do so well at it.

http://www.cyclecoach.com
http://www.aerocoach.com.au
Last edited by: AlexS: Jun 15, 18 16:59
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Re: TTE / FTP Question [AlexS] [ In reply to ]
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deleted...


My apologies. I did get that wrong
Last edited by: paull: Jun 14, 18 23:52
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Re: TTE / FTP Question [Trev] [ In reply to ]
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What is interesting, to me, is that at a certain intensity, the working muscles will desaturate. They can not get enough oxygen from the blood, oxygen saturation will drop and anaerobic metabolism will have to dump metabolites into the bloodstream faster than we can get rid of them. It does not matter that one can go a little harder if one does not have to go on for as long, what is interesting is this physiological fact. Why? Because desaturation will drive adaptation!

Endurance coach | Physiotherapist (primary care) | Bikefitter | Swede
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Re: TTE / FTP Question [Kiwicoach] [ In reply to ]
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Kiwicoach wrote:
Functional Threshold Power is an estimate of the point where we transition from using a mix of carbohydrate and fat to solely using our finite CHO stores. This point is observable when doing ramp tests or the MLSS test.

Is this true?

I always understood that fat metabolism was a relatively constant background rate with maybe a dip in total energy per hour above FTP, but not a complete shutdown. I thought that the point of the FTP/LT was that greater and greater PERCENTAGE of energy supply was coming from higher availability sources (muscle / liver glycogen, anaerobic CHO) which have limited supply and greater lactate byproducts. However, as long as CHO was available, fat metabolism would continue to contribute in the background (again, perhaps at a reduced level, eg: 300 cal / hr down to 200-150 cal / hr...just no ZERO).

Maybe this is this the point where we BEGIN to transition to lower absolute fat contribution (and ultimately reach zero for a 30s effort or something)?
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Re: TTE / FTP Question [Tom_hampton] [ In reply to ]
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Difficult question to explicitly answer, since substrate oxidation also depends on diet, duration, etc. Hyperventilation at high exercise intensities can also undermine the validity of RER as a quantitative measure of fat vs. carbohydrate oxidation.

That said, some studies have indeed use RER = 1.00 to estimate "threshold" during incremental exercise tests, just as Hamish indicated (although at the same time, many years ago Larry Spriet published data showing mobilization of IMTG stores even during intense electrical stimulation of isolated rat muscle).

TL; DR: As with all such things, it's complicated. If you are only interested in getting faster, it's probably best to ignore such details and just get on with your training.
Last edited by: Andrew Coggan: Jun 15, 18 8:54
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Re: TTE / FTP Question [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Difficult question to explicitly answer, since substrate oxidation also depends on diet, duration, etc. Hyperventilation at high exercise intensities can also undermine the validity of RER as a quantitative measure of fat vs. carbohydrate oxidation.

That said, some studies have indeed use RER = 1.00 to estimate "threshold" during incremental exercise tests, just as Hamish indicated (although at the same time, many years ago Larry Spriet published data showing mobilization of IMTG stores even during intense electrical stimulation of isolated rat muscle).

TL; DR: As with all such things, it's complicated. If you are only interested in getting faster, it's probably best to ignore such details and just get on with your training.


If I could simply train all the time....that's what I'd do, and I wouldn't be on ST much. Unfortunately, recovery leaves lots of time for pondering these things--and, I like understanding things. At 50 I seem to have more recovery time. I'm okay with complicated...I'm also ok with "in general <blah blah blah>, but there are lots of variations."

RER=??

IMTG = intra-muscular triglycerides?

ETA: I'm also ok with a pointer to a few studies that you think validly demonstrate the situation.
Last edited by: Tom_hampton: Jun 15, 18 9:23
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Re: TTE / FTP Question [Tom_hampton] [ In reply to ]
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Tom_hampton wrote:


If I could simply train all the time....that's what I'd do, and I wouldn't be on ST much. Unfortunately, recovery leaves lots of time for pondering these things--and, I like understanding things. At 50 I seem to have more recovery time. I'm okay with complicated...I'm also ok with "in general <blah blah blah>, but there are lots of variations."

RER=??

IMTG = intra-muscular triglycerides?

ETA: I'm also ok with a pointer to a few studies that you think validly demonstrate the situation.


https://en.wikipedia.org/...atory_exchange_ratio

The respiratory exchange ratio (RER) is the ratio between the amount of carbon dioxide (CO2) produced in metabolism and oxygen (O2) used.[1]
The ratio is determined by comparing exhaled gases to room air. Measuring this ratio can be used for estimating the respiratory quotient (RQ), an indicator of which fuel (carbohydrate or fat) is being metabolized to supply the body with energy. This estimation is only valid if metabolism is in a steady state

Oxidation of a carbohydrate molecule




Oxidation of a fatty acid molecule


Last edited by: paull: Jun 16, 18 4:54
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