Power Meter Terminology

Strange Rover
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Power Meter Terminology

Postby Strange Rover » Mon May 03, 2010 3:53 pm

Now I dont have a power meter but would love to one day. I find all the talk on power stuff really interesting but really dont have a clue on some of the language.

So can anybody interpret what is being said here...
twizzle wrote:Never go on a PedalPower 'social ride' with guys who turn out to be A graders. At one point there were four of us in a pace line hammering along at 53km/h on a 1% descent.

132.9km in 6:15 (4:15 ride time). 31.3km/h, 3911Kj, 253w average/286w NP, IF .793.

Aerobic Decoupling 2.36%. I guess I don't need any more base...

I think this one post has got most of the good terms in it but if there are other common terms that are used then feel free to explain them also.

Thanks in advanced.

Sam

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toolonglegs
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Re: Power Meter Terminology

Postby toolonglegs » Mon May 03, 2010 4:49 pm

3911Kj...the amount of work done... measured by the power meter (not what the body has actually burnt...but is a much more accurate way of telling how much energy you have used compared to the guesstimate of a heart rate device ).But basically,3911Kj is close enough to 3900 Kcal if you are watching your waist line.

253w av...the actual average watts for the duration of your ride.Some power meter recording devices allow you to ignore the none pedaling times in your average.That is left up to you to decide.Similar to a speedo set to just record the time you are actually rolling...not sitting at the lights.

286w NP...Normalized Power,an estimation of the power you could of maintained for the same "physical cost" if you effort had been constant...basically if you had ridden a constant TT instead of having many accelerations and soft pedalling moments.A good way to know what say a hard race "would" have averaged (cost you phsyically) if you had ridden steadily though out.Not of much use under 20 minutes...really a good indicator for hour long efforts etc.

IF...793 The ratio of Normalized Power to a riders FTP.

So then we must mention FTP (Functional Threshold Power)...basically your maximum hour power...what you could sustain in a best effort for an hour or close to.Like a 40km TT for example.Probably the most important number for an endurance cyclist....and the number you are always striving to improve as it basically affects all other areas.
Aerobic Decoupling 2.36%
I have no idea :lol:

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Alex Simmons/RST
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Re: Power Meter Terminology

Postby Alex Simmons/RST » Mon May 03, 2010 5:09 pm

toolonglegs wrote:
Aerobic Decoupling 2.36%
I have no idea :lol:
I wouldn't bother finding out either.

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toolonglegs
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Re: Power Meter Terminology

Postby toolonglegs » Mon May 03, 2010 5:17 pm

Alex Simmons/RST wrote:
toolonglegs wrote:
Aerobic Decoupling 2.36%
I have no idea :lol:
I wouldn't bother finding out either.
:lol:

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JV911
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Re: Power Meter Terminology

Postby JV911 » Mon May 03, 2010 7:32 pm

any suggested books/reading for a PM noob?
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toolonglegs
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Re: Power Meter Terminology

Postby toolonglegs » Mon May 03, 2010 7:46 pm

JV911 wrote:any suggested books/reading for a PM noob?
Only one needs suggesting...but there is a new edition out or about to be out.
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twizzle
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Re: Power Meter Terminology

Postby twizzle » Mon May 03, 2010 8:28 pm

Alex Simmons/RST wrote:
toolonglegs wrote:
Aerobic Decoupling 2.36%
I have no idea :lol:
I wouldn't bother finding out either.
I'm hurt. :sad:

:P I take it that's it's a useless measurement we should all ignore?
I ride, therefore I am. But don't ride into harm's way.
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Alex Simmons/RST
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Re: Power Meter Terminology

Postby Alex Simmons/RST » Tue May 04, 2010 8:44 am

twizzle wrote:I'm hurt. :sad:

:P I take it that's it's a useless measurement we should all ignore?
Find me some evidence that it has any basis or practical use and I might change my mind.

It really only provides any consistent information when the effort is controlled, fairly steady (e.g. dead flat terrain or turbo trainer) and at lower training levels. So that rules out most decent training / racing.

Joe Friel wrote about it:
http://home.trainingpeaks.com/articles/ ... friel.aspx

Personally you are far better off seeing if power is improving since, well, that's what drives us down the road.

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Re: Power Meter Terminology

Postby twizzle » Tue May 04, 2010 11:50 am

Alex Simmons/RST wrote:
twizzle wrote:I'm hurt. :sad:

:P I take it that's it's a useless measurement we should all ignore?
Find me some evidence that it has any basis or practical use and I might change my mind.

It really only provides any consistent information when the effort is controlled, fairly steady (e.g. dead flat terrain or turbo trainer) and at lower training levels. So that rules out most decent training / racing.

Joe Friel wrote about it:
http://home.trainingpeaks.com/articles/ ... friel.aspx

Personally you are far better off seeing if power is improving since, well, that's what drives us down the road.
Reading the article, it doesn't seem to be negative towards using decoupling as a measure of endurance fitness, although the explanation I had read hadn't stressed the need to maintain relatively constant power or HR. Looking at the data from my ride on Sunday, even though I was damned tired the HR and Power were still trending together for the last hour, when I was pretty much TT'ing home (leave pass had expired).
I ride, therefore I am. But don't ride into harm's way.
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Alex Simmons/RST
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Re: Power Meter Terminology

Postby Alex Simmons/RST » Tue May 04, 2010 12:11 pm

twizzle wrote:Reading the article, it doesn't seem to be negative towards using decoupling as a measure of endurance fitness,
Probably because it's the author who's promoting it as something useful.
twizzle wrote:although the explanation I had read hadn't stressed the need to maintain relatively constant power or HR.
Well that's what you gain from experience.

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Re: Power Meter Terminology

Postby Strange Rover » Thu May 06, 2010 9:35 pm

OK...got another one...
toolonglegs wrote:So in 1 hour I can do 4 x 5 minutes at VO2 or 2 x 20 minutes at FTP...but try and explain that to people :lol: .

So what is V02..im guessing just flat out??

Also - what sort of power do any of you power meter guys produce when riding at a constant 30 or 40 or 50km/h on flat ground with no wind...not after exact measurements but just something to get a more of a feel of what the power numbers mean.

Thanks again.

Sam

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toolonglegs
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Re: Power Meter Terminology

Postby toolonglegs » Thu May 06, 2010 9:58 pm

VO2 for me....is 110% to 130% of FTP roughly.
No not flat out...but a 5 minute effort at a higher pace than ftp...that you can hold steady for 5 minutes...then have a similar length rest and be able to do it again.They are not easy that is for sure.

No idea on the other question....really is way too many variables.But have a look at analytic cycling or similar and they give you are good idea.

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Alex Simmons/RST
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Re: Power Meter Terminology

Postby Alex Simmons/RST » Fri May 07, 2010 4:54 pm

Strange Rover wrote:So what is V02..im guessing just flat out??
VO2 refers to the volume (in litres) of oxygen utilised by the body.

The more O2 utilised per unit time, the greater the power output.

VO2max refers to the maximal rate of oxygen utilisation, usually expressed in litres per minute. It is also often quoted per unit of body mass (kg) to normalise it across riders of different sizes.
Strange Rover wrote:Also - what sort of power do any of you power meter guys produce when riding at a constant 30 or 40 or 50km/h on flat ground with no wind...not after exact measurements but just something to get a more of a feel of what the power numbers mean.
One cannot provide such an estimate as it is so dependent on a range of variables. It be could anywhere from 100 watts for a smaller and very aero rider at 30km/h to 1000 watts for a large and un-aero rider at 50km/h.

go to this site if you want to play with some numbers:
http://analyticcycling.com/

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