The Powermeter Thread

[Alex Simmons/RST]

I end up with negative watts while regeneration braking into my bionic leg implants. The 1973 originals cost $6m but they've now worn out, looks like I'm going to have to fork out $600m to replace them. Unbelievable! Anyway I have a new bike made from unobtanium and it goes fast enough to blow the curls right out of Farrah's hair... just wondering if anyone makes a powermeter that can measure power at my titanium ankles? That way no matter which bike I've got, no matter what shoes I'm wearing, whether running, walking, swimming or kicking someone in the head, left foot, right foot, power output or input, I'm getting a continuous reading to my bionic eye headsup display. Regards Steve Austin.

My SRMs did just fine recording the power from my bionic leg.


PS - Oscar sends his regards.

 

[Polyarmour]

My SRMs did just fine recording the power from my bionic leg.


PS - Oscar sends his regards.

Lol Alex, I forgot about your bionic leg. (even though it's right there on your photo)
And I thought I had an exclusive arrangement with Oscar G?
I don't want my bionic leg secrets getting out.
Look what happened to Pistorius after Oliveira "bugged" his blades with a PM.

 

[CoachFergie]

http://www.scientificamerican.com/article.cfm?id=just-a-theory-7-misused-science-words

 

[FrankDay]

http://www.scientificamerican.com/article.cfm?id=just-a-theory-7-misused-science-words

What a good idea (getting rid of more precise terms - because a lot of people misuse/misunderstand them - for less precise terms) - NOT. We will be able to talk about the evolutionary model and intelligent design model using similar words making it easier to imply they are equals.

Anyhow, from the article:

But though these words may be routinely misunderstood, the real problem, scientists say, is that people don't get rigorous science education in middle school and high school. As a result, the public doesn't understand how scientific explanations are formed, tested and accepted.

If people are trying to have a true discussion it seems to me important that they make sure that the other participants understand how they are using specific words if some confusion arises. As the article points out, different disciplines may define the same word differently such that confusion can arise unless how each is using the word is clarified. (Edit: And, of course, if lay people are involved the issues are compounded.)

 

[Alex Simmons/RST]

What a good idea (getting rid of more precise terms - because a lot of people misuse/misunderstand them - for less precise terms) - NOT. We will be able to talk about the evolutionary model and intelligent design model using similar words making it easier to imply they are equals.

Anyhow, from the article:
If people are trying to have a true discussion it seems to me important that they make sure that the other participants understand how they are using specific words if some confusion arises. As the article points out, different disciplines may define the same word differently such that confusion can arise unless how each is using the word is clarified. (Edit: And, of course, if lay people are involved the issues are compounded.)

Unlike you of course ;-)

Exhibit A

Exhibit B

 

[FrankDay]

Unlike you of course ;-)

Exhibit A

Exhibit B

Huh?

In the example you linked one person (Dr. Coggan) tries to hold a whole thread hostage to his particular definition of a word when others are trying to have a discussion using another, perfectly valid, definition. I would have had no problem if Dr. Coggan would have said in that thread "you know in exercise physiology we use the word "strength" this way and what you guys are trying to discuss I would call X." But he didn't. He simply refused to give an alternative term for what people were trying to discuss. If you will note, in Exhiibit A I actually tried to give reference to a definition of the word strength which would have allowed the conversation to continue despite using, in the eyes of a strict exercise physiologist, an inferior term. Dr. Coggan, sees himself as being so superior he simply couldn't allow it because how others were using the word didn't jibe with what he thought was the only proper definition.

 

[CoachFergie]

Not sure if I posted this, but a good overview of using TrainingPeaks to manage the riding and racing process using a power meter as a measurement tool...

http://www.youtube.com/watch?v=Mn5go5zeM8U

And of course, for those who are wanting to take things to the next level Andy's webinar 2 is on tomorrrow!!!

"The New Science of WKO+4, Part II: Limitations of Current Models"

http://support.trainingpeaks.com/athlete-edition/webinar-schedule.aspx

 

[CoachFergie]

Looking forward to more discussion about the models using W' and FRC.

I have a trial version of RaceDay software that allows one to see W' although it looks like Golden Cheetah plan to incorporate this in their version 3.1. Neither programme is as flexible and easy to use as WKO+ so suspect there is a bit of GIGO going on.

Here is the chart from a MAP (Max Aerobic Power) test I did last night showing that even with a 10min gap between a warm up effort and the test W' did not fully recover.

We have Oceania Track Cycling Champs next week so hiring an SRM for one of my U19's so will be interesting to compare what RaceDay shows by comparison to WKO+ 4.0 in modelling how the rider goes in her various sprint events.

 

[acoggan]

Looking forward to more discussion about the models using W' and FRC.

I have a trial version of RaceDay software that allows one to see W' although it looks like Golden Cheetah plan to incorporate this in their version 3.1. Neither programme is as flexible and easy to use as WKO+ so suspect there is a bit of GIGO going on.

Here is the chart from a MAP (Max Aerobic Power) test I did last night showing that even with a 10min gap between a warm up effort and the test W' did not fully recover.

We have Oceania Track Cycling Champs next week so hiring an SRM for one of my U19's so will be interesting to compare what RaceDay shows by comparison to WKO+ 4.0 in modelling how the rider goes in her various sprint events.

1. Make sure you don't confuse W' (AWC) with W' balance. The former has been around for almost 50 y; the latter for only a couple.

2. I assume you went to failure during each of the ramp tests? If so, any idea why your W' balance was markedly different at the point of fatigue in the two tests?

 

[CoachFergie]

If only there was some information out there about the limitations of the current models. A webinar perhaps

 

[Alex Simmons/RST]

2. I assume you went to failure during each of the ramp tests? If so, any idea why your W' balance was markedly different at the point of fatigue in the two tests?

I think the initial effort was intended as a warm up only, not to failure. At least Fergie mentioned the warm up.

Quite a solid warm up, not sure I'd be doing a steady ramp up to more than 90% of MAP as my MAP test warm up.

I usually have warm up as a mix of effort in levels 1/2/3, mostly L2, with a couple of 30-second L4 efforts. Nothing nearly as strenuous as in Fergie's example.

 

[CoachFergie]

I think the initial effort was intended as a warm up only, not to failure. At least Fergie mentioned the warm up.

Quite a solid warm up, not sure I'd be doing a steady ramp up to more than 90% of MAP as my MAP test warm up.

I usually have warm up as a mix of effort in levels 1/2/3, mostly L2, with a couple of 30-second L4 efforts. Nothing nearly as strenuous as in Fergie's example.

It's a fairly common warm up I use for track. Simon Jones said the Brits use it and but didn't go into too much detail about the progressive effort. I see Team Sky do the same 8 min progressive (Simon was Wiggin's coach) effort and do specify to level 5 power (seeing they use TrainingPeaks I assume that is the Coggan level 5). But instead of the 30sec effort they do 3 x 6sec sprints.

Perhaps I will try that when I have another go at a MAP before I'm on the road for two weeks.

Just going to brush up on W' balance now but suspect in 45min I will learn why these current models just don't seem to cut it

 

[Alex Simmons/RST]

I doubt it'd make much difference TBH.

Precise warm up protocols are more for the head than the legs.

 

[sciguy]

Just in case anyone missed this over on the Wattage list, Garmin just released new versions of the 810 and 510 firmware that allow one to disable the sometimes dicey auto-zero function for SRM power meters. It took a while but I'm glad to see they've made this much requested upgrade.

http://www8.garmin.com/support/download_details.jsp?id=6005

Hugh

 

[Alex Simmons/RST]

Just in case anyone missed this over on the Wattage list, Garmin just released new versions of the 810 and 510 firmware that allow one to disable the sometimes dicey auto-zero function for SRM power meters. It took a while but I'm glad to see they've made this much requested upgrade.

http://www8.garmin.com/support/download_details.jsp?id=6005

Hugh

+1

Better late than never!

 

[CoachFergie]

Part 2...

http://www.youtube.com/watch?list=PLOhzd0zmrJzlKlDksLr5vT7Ujw94wjc1F&v=H6_bU5hL9xM

And a teaser for part 3!

 

[FrankDay]

Part 2...

http://www.youtube.com/watch?list=PLOhzd0zmrJzlKlDksLr5vT7Ujw94wjc1F&v=H6_bU5hL9xM

And a teaser for part 3!

I look forward to listening to the next two parts. Hopefully they will fix their sound issue as a good portion of part two there was no sound. It is too bad he didn't include WKO3 in his model analysis but maybe he will address that next week when he shows how much better WKO4 is.

The question still remains in my mind regarding the real world usefulness to the individual athlete of such a model. It may mean that academics are beginning to better understand what is involved in athletic performance but does knowing this (and being able to describe it) result in better outcomes for those who use it? We will see if that gets addressed.

 

[elapid]

... but does knowing this (and being able to describe it) result in better outcomes for those who use it? We will see if that gets addressed.

 

[acoggan]

It is too bad he didn't include WKO3 in his model analysis

There is no model of the power-duration relationship in WKO+3?

 

[CoachFergie]

I doubt it'd make much difference TBH.

Precise warm up protocols are more for the head than the legs.

True.

Tried the Team Sky variation of the warm up, also at a higher TSB of -8 than -13 and the result, of course one off results always being taken with a grain of salt, was an 18 watt difference to Monday.

The chart from RaceDay...

Look forward to revisiting these files in WKO+ 4.0 to see what else I can refine in the training, racing, recovery, warm up, taper process to squeak out a few more watts!

 

[FrankDay]

There is no model of the power-duration relationship in WKO+3?

Not having actually used WKO+3 perhaps I was misinformed as to what kind of information came to people who used the product. But, it was my understanding that people who put in their power data got estimates of their FTP and graphs showing their mean maximal power for different durations and that people then used this to estimate their power potential for different durations to help them plan racing and training strategy. While not a "model" in the strictest sense, I guess, didn't this appear to be a "model" to the typical user?

It seems to me if all this is about is your developing what you believe to be a good power/duration model that this would not necessitate a completely new book compared to simply revising your old one.

Then again, you and I agree, that the importance of a model isn't in whether it is right or wrong but in its usefulness. I look forward to seeing part 3 to see what you really got and how you anticipate this data being used by the athlete.

 

[CoachFergie]

Int J Sports Med
DOI: 10.1055/s-0033-1349093

The 3-min Test Does not Provide a Valid Measure of Critical Power Using the SRM Isokinetic Mode

B. Karsten, S. A. Jobson, J. Hopker, L. Passfield, C. Beedie

Abstract

Recent datas suggest that the mean power over the final 30 s of a 3-min all-out test is equivalent to Critical Power (CP) using the linear ergometer mode. The purpose of the present study was to identify whether this is also true using an “isokinetic mode”. 13 cyclists performed: 1) a ramp test; 2) three 3-min all-out trials to establish End Power (EP) and work done above EP (WEP); and 3) 3 constant work rate trials to determine CP and the work done above CP (W′) using the work-time (=CP1/W′1) and 1/time (=CP2/W′2) models. Coefficient of variation in EP was 4.45% between trials 1 and 2, and 4.29% between trials 2 and 3. Limits of Agreement for trials 1–2 and trials 2–3 were −2±38 W. Significant differences were observed between EP and CP1 (+37 W, P<0.001), between WEP and W′1(−6.2 kJ, P=0.001), between EP and CP2 (+31 W, P<0.001) and between WEP and W′2 (−4.2 kJ, P=0.006). Average SEE values for EP-CP1 and EP-CP2 of 7.1% and 6.6% respectively were identified. Data suggest that using an isokinetic mode 3-min all-out test, while yielding a reliable measure of EP, does not provide a valid measure of CP.

Key words

critical intensity - exercise testing - anaerobic work capacity - reliability - validity

 

[CoachFergie]

Int J Sports Med
DOI: 10.1055/s-0033-1355352

The Use of Velodrome Tests to Evaluate Aerodynamic Drag in Professional Cyclists

J. García-López, A. Ogueta-Alday, J. Larrazabal, J. A. Rodríguez-Marroyo

Abstract

The purpose of this study was to analyse the validity, reliability and sensitivity of velodrome tests to detect small changes in aerodynamic drag in cycling. 12 professional cyclists were assessed to obtain the drag area (SCx) during wind tunnel and velodrome tests. Incremental and steady-state protocols were performed in the velodrome with a portable power meter, and 6 bicycle positions were analysed and compared that involved lowering the handlebars and advancing the pads between 2–5 cm. A significant relationship (r=0.88, p<0.001) between the SCx in the wind tunnel and velodrome tests was found (0.240±0.007 and 0.237±0.008 m2, respectively). The velodrome tests underestimated the SCx (0.0035±0.0038 m2 and p<0.01), which decreased (p<0.001) when the bicycle speed increased (0.0013 m2 each 1 km · h−1). The SCx values showed high reliability during the steady-state (r=0.99, p<0.001) and incremental protocols (r=0.94, p<0.001). Small changes in the aerodynamic position affected the SCx (p<0.001), which decreased by 0.011±0.007 m2 (4.6±2.9%, 95% CI=2.7–6.4%). In conclusion, the validity, reliability and sensitivity of velodrome tests to detect small changes in aerodynamic drag in cycling were demonstrated. Although SCx values were not interchangeable between different studies, the velodrome tests presented advantages with respect to the wind tunnel tests.

Key words

cycling - biomechanics - aerodynamics - time-trial

 

[CoachFergie]

Int J Sports Med
DOI: 10.1055/s-0033-1349844

High Agreement between Laboratory and Field Estimates of Critical Power in Cycling

B. Karsten, S. A. Jobson, J. Hopker, A. Jimenez, C. Beedie

Abstract

The purpose of this study was to investigate the level of agreement between laboratory-based estimates of critical power (CP) and results taken from a novel field test. Subjects were fourteen trained cyclists (age 40±7 yrs; body mass 70.2±6.5 kg; V̇O2max 3.8±0.5 L · min−1). Laboratory-based CP was estimated from 3 constant work-rate tests at 80%, 100% and 105% of maximal aerobic power (MAP). Field-based CP was estimated from 3 all-out tests performed on an outdoor velodrome over fixed durations of 3, 7 and 12 min. Using the linear work limit (Wlim) vs. time limit (Tlim) relation for the estimation of CP1 values and the inverse time (1/t) vs. power (P) models for the estimation of CP2 values, field-based CP1 and CP2 values did not significantly differ from laboratory-based values (234±24.4 W vs. 234±25.5 W (CP1); P<0.001; limits of agreement [LOA], −10.98–10.8 W and 236±29.1 W vs. 235±24.1 W (CP2); P<0.001; [LOA], −13.88–17.3 W. Mean prediction errors for laboratory and field estimates were 2.2% (CP) and 27% (W′). Data suggest that employing all-out field tests lasting 3, 7 and 12 min has potential utility in the estimation of CP.

Key words

critical intensity - exercise testing - power-duration relationship

 

[sittingbison]

...It is too bad he didn't include WKO3 in his model analysis but maybe he will address that next week when he shows how much better WKO4 is... but does knowing this (and being able to describe it) result in better outcomes for those who use it?...

Not having actually used WKO+3 perhaps I was misinformed as to what kind of information came to people who used the product.....

Frank you are outta here