I am glad to see you took intro Logic in college (entry qualifications must be low in the U.S.).

http://www.nizkor.org/...eal-to-ridicule.html

Obviously, I'm kidding. But, seriously, congratulations on the '89 FIFA World Youths. That must have been awesome.

Winning the Champions League in consecutive years for different clubs wasn't so bad either.

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It's too variable and effected by to may outside influences. It's really a horrible metric to use for anything as a whole, but in a lot of cases it's the only information we could get outside the lab.

No doubt.

I gotta say, I only care mildly about this general topic but the conversation has been fascinating and very entertaining.

I think the Lavendar room has crept into the main forum.

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Jen

"In order to keep a true perspective on one's importance, everyone should have a dog that worships him and a cat that will ignore him." - Dereke Bruce

pretty sure I ridiculed you and then told you your argument was unimportant (not false). Was that little bit about my intelligence a rebuttal against me and not my logic??? Hmmmm.... I'm sure there is a name for that, too bad I'm too dumb to remember it. Oh well, I will let the smarter people continue to ridicule you. Good luck with the step aerobics and Special K.

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I never noted any ridicule in your response, nor did I see any address about the context of my argument. Perhaps a little remedial reading class is in my future!
What logic was demonstrated in your original post that I would have attempted to ridicule?


Thank you for knowing your place. I will enjoy the step aerobics and Special K immensely. Always do. I hope you have a good time training for triathlon as well.

I am afraid this place appears worse.

True, but I'm starting to get curious though, since this definitely isn't the first time you've brought this up. I'm curious as to how I might have acquired a reputation in the local community that is even the slightest bit negative.


Paulo called me an idiot. You're talking about my reputation. I'm not saying there are hard feelings (except maybe Paulo--I still don't think his contributions are as constructive as he thinks they are), and I totally had a man-child reaction to the thread yesterday, but it absolutely is personal on some level.


Along the same lines as above, I don't think Paulo is as helpful as he thinks he is. In some ways Paulo may be the smartest one here for hardly getting involved, or for not actually articulating his point of view, instead replying with monosyllabic answers and pejorative remarks, thereby avoiding the issue of having his own opinions and sources torn apart.
Paulo's first response was
"You don't know what you're talking about. You do sound incredibly authoritative, which makes me think you're either very young or very idiot. "
followed by:
"Wrong."
"Wrong."
"I am not going to do your homework for you. But hopefully you're able to use The Google. "
I suppose I should know to expect that level of uselessness from him. If all he's going to do is show up and say "yes" or "no" then why even bother. I can't even begin to understand the motivations of someone who has enough of a desire to help out that they post, but not enough that they're willing to post something substantive even when prompted many, many times. I don't believe in spoon-feeding people information either, but there's a difference between A) Being intentionally obtuse, B) sending someone a link and letting them drawing their own conclusions, and C) posting a link and writing out the spoiler right there as well. I spent a good 2-3 hours researching this yesterday using my school's journal database, and I couldn't find anything supporting Paulo's argument. I think anyone who truly claimed to care about helping someone learn would step in at that point at least and help out. I certainly don't think Paulo owes it to me to help, but if he's going to fuck with me then he at least has to expect that I'll get pissed at him when he serves no useful purpose to me. It's also worth noting that I was getting pissed at Paulo's little troll minion Seasonschange as well, but was mostly just replying with double the frustration to PS.

That said, I still have yet to see A SINGLE article supporting the use of power-based measurements. Unless I missed something, I believe all anyone could do was refute the HR argument--nobody could prove the validity of the power argument (except for one post that mentioned off-handedly that one of the studies happened to use the 25% efficiency figure in an equation somewhere). That's a non-trivial thing, and has yet to be substantiated. That frustrates me on a lot of levels. I think if the tables were turned, and there were 10 or so people trying to pick apart the power meter calorie measurement method it wouldn't be that difficult to find a hole here or there.

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You won't see specific "power" based studies like you're thinking of. Why would they spend the money to do studies with the powermeter when they use full cycles built specifically for this kind of testing?

Do a search for "cycle ergometry studies" to find what you are looking for.

And as much as it might sting, Paulo's assessments were correct. Either you are young and not developed much in critical thinking and assessment, or you stubbornly cling to a belief when several people attempt to point out why it is an erroneous belief. Your adherence to the HR stance simply prompted more "wrong" responses, since it was, well, wrong.

John

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I'm not sure there has to be an article, does there? The FACT that 1KJ = 1Kcal should be evidence enough to talk calories expended. Maybe I'm wrong, I dunno.

Here's a snippet from a ride I did last January. It was a ~4hr group ride, which turn into bike races sometimes.

Entire workout (153 watts):
Duration: 3:50:01 (4:12:11)
Work: 2093 kJ
TSS: 211.6 (intensity factor 0.756)
Norm Power: 223
VI: 1.46
Pw:HR: n/a
Pa:HR: n/a
Distance: 66.997 mi
Elevation Gain: 2116 ft
Elevation Loss: 2128 ft
Grade: -0.0 % (-12 ft)
Min Max Avg
Power: 0 1252 153 watts
Cadence: 30 246 83 rpm
Speed: 0 39.7 17.2 mph
Pace 1:31 0:00 3:29 min/mi
Altitude: 570 852 693 ft
Crank Torque: 0 1259 163 lb-in

ETA: I really wish (but only for the sake of this comparison) that I used a HR monitor b/c garmin connect estimates calories expended using that so it'd be interesting to compare the Powertap's WKO+ KJ/kcal with the Garmin's HR "calories."


I've "bolded" the important part. So I'm assuming that I burned appx 2093 kcals on this ride. Don't worry about being on edge, it's the off-season. Everyone is on edge in some way.

I posted the math before. Are you looking for an article that shows the range of cycling efficiency in riders?


It's pretty easy, you measure the output through a power meter, then from there you can estimate the calories burned by estimating the riders efficiency.


The efficiency that most people use is around 23-24% for trained cyclists, although I don't have a study to back that claim up that the majority of trained cyclists have that efficiency. Maybe that's what you're looking for?

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Co-host of the Ask a Cycling Coach Podcast

That's exactly what I'm looking for!

I understand how the system works. Your calories burned are proportional to your efficiency and rear wheel power (with appropriate conversion factors applied). That part I don't think anyone can disagree with, and I certainly never have. I've only taken issue with the lack of evidence proving the range of efficiencies that everyone keeps quoting. Thanks to Devlin, I looked for cycling ergometry + efficiency and had much better luck. Thank you! Have a look at this one:
Efficiency in cycling: a review
Gertjan Ettema1 and Håvard Wuttudal Lorås1
[/url](1) Human Movement Science Programme, Faculty of Social Sciences and Technology Management, Norwegian University of Science and Technology, 7941 Trondheim, Norway


The executive summary is that the r^2 for the best fit line representing the data points connecting metabolic work rate and external power looks a lot better than that connecting GME and external power.

Figure 2a shows the data according to cadence. Even though most studies report a clear negative effect of cadence on gross efficiency, the overall picture shows a minimal effect. The inter-study variation is much larger than any visible trend, and some studies show the opposite (positive) effect or an inverted u-shape with an optimal cadence. The inter-study variation may easily be thought to be caused by methodological differences. However, when plotting the same pool of data against external power, a different picture is shown. A very consistent relationship between work rate and efficiency is found. This relationship is even more clearly demonstrated by plotting the metabolic rate against work rate (Fig. 2c). A linear relationship is found, which is not unexpected but merely reflecting what various studies have reported explicitly (e.g., Anton-Kuchly et al. 1984; Bijker et al. 2001, 2002; Chavarren and Calbet 1999; Coast and Welch 1985; Francescato et al. 1995; Gaesser and Brooks 1975; Hintzy-Cloutier et al. 2003; McDaniel et al. 2002; Moseley et al.2004; Widrick et al. 1992). As stated before, the curved work rate–gross efficiency relationship is a consequence of the offset (y-intercept) of the work rate–metabolic rate relationship. Note, that this offset does not, per sé, indicate any fixed baseline energy cost that, physiologically, is independent of work rate. The rather surprising aspect of the result is the high consistency between the various studies regarding the work rate–metabolic rate relationship, where it seems to be lacking as a function of cadence. Although one should be cautious with the interpretation of correlations here, that between metabolic rate and external power amounts to 0.97 (n = 93, p < 0.0001; 26 studies, 29 conditions/subject groups, meaning that 94% of the variation among all (mean) energy expenditure values for all these situations is explained by absolute work rate. This outcome is only slightly more ambivalent when separate data for all different cadences at the same power output were entered (in 9 studies), as shown in Fig. 2e. Also when converting the data to work rate-efficiency curves, only small differences with the original calculations occur (Fig. 2f), with the correlation being reduced to 0.95 (r 2 = 0.91). In other words, factors other than work rate, including cadence, explain less then 10% of the variation in energy expenditure. Adding cadence as a dependent factor, the explained variance is increased to 94% (cadence explains about 10% on its own). These findings, both correlation values as well as the absolute cost-work rate relationship, agree well with McDaniel et al. (2002) (redrawn in grey in Fig. 2c, but not included in the analysis), who looked at cadence, work rate and movement speed (by altering crank length). In their study, 95% of all variation in metabolic cost, including all experimental conditions, was explained by work rate. In the present data pool, cadence and power are correlated to some extent (r = 0.171, p < 0.019; Fig. 3a), which complicates the interpretation somewhat as these two factors share some of their variance. Still, both factors seem reasonably evenly spread over all data considered in this overview (Fig. 3a). Therefore, it is unlikely that this correlation between work rate and cadence has a strong effect on the findings. Interestingly, the intercept of the two-dimensional regression at zero work rate and zero cadence (Fig. 3b), which would be the theoretical value for energy expenditure while sitting still on a bicycle, reaches a value of 40 W (not statistically significant from zero). This value is too low, but still physically possible, despite the rather large extrapolation range from the experimental data. Overall, it seems that the very original findings by Fenn (1924) on isolated muscle also apply to the entire human body in cycling in a very consistent manner.

+

Lucia et al. (2002) reported rather high gross efficiency values for some top cyclists. The average for the group amounted to 24.5% (with a peak individual value at 28.1%). Jeukendrup et al. (2003) argued that these results were extremely high from a theoretical point-of-view and must have been affected by errors in the measurements (see also below, next section). They furthermore concluded that if these data were correct, “some interesting physiological adaptations may exist…”. Coyle (2005) reported an increase in efficiency over a period of 7 years of training and competing in one of the most outstanding cyclists of modern times from about 21–23%. Coyle proposed that biochemical adaptations may have caused this improvement (i.e., a greater contribution from aerobically-efficient type I fibres). When considering these data and their placement within the data derived from the literature (Fig. 2b, c; data enclosed in a grey square; only overall average is shown for both studies), these values do not seem extraordinary, although Lucia et al. (2002) appear to show a slightly high efficiency value. This is supported by values from Sallet et al. (2006) on elite and professional riders who score even higher efficiencies at powers above 400 W (data most to the left in Fig. 2b, c). The main reason why gross efficiency is relatively high is likely because of the high work rate. Also the improvement in efficiency reported by Coyle (2005) may be explained by an increased power at which these values were determined. Nevertheless, the studies by Sallet et al. (2006) and Lucia et al. (2002) show metabolic rates below the regression line in Fig. 2c, which may indicate either measurement error or, indeed, some physiological changes that enhance efficiency above the increase that is directly linked to that for the work rate. It is interesting to note that the same group (Lucia et al. 2004) report a lower efficiency is reported (23.4 vs. 24.5%) at a slightly lower power (366 vs. 385 W).

+

Irrespective of definitions and concepts, a framework for the accuracy of efficiency measurements can be established. It seems reasonable to allow for a 5% error in biological measurements with regard to studies on cycling efficiency. Figure 2d shows the ranges of efficiency calculations that arise from 5% error in both metabolic rate and external power going in opposite directions. The vertical bar shows the range near 300 W if only one of these measures has that same error. Only one data point falls clearly outside the range of 5% error (filled circle). This is the result from Luhtanen et al. (1987) at the highest work rate, which was, as mentioned earlier, well above the lactate threshold and thus bound to result in a lower efficiency. Thus, the difference between studies may be partly explained by differences in (systematic) errors. This merely strengthens the notion that cycling is an extremely consistent exercise model with regard to the relationship between metabolic rate and external power. Thus, the situation presented in Fig. 2c may constitute a very solid framework for the interpretation of past, present and future
studies.




**Edit to add figures**

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Yes, you're wrong. The 1kJ to Cal conversion is a conservative approximation assuming about a 24% efficiency which is at the high end of measured efficiency for athletes. If you happened to be 20% efficient you would have burned 2500 Cals instead of the 2093 you assumed.

If you're trying to lose weight it's better to underestimate caloric expenditures, so most people assume the 24% efficiency which leads to 1kJ of work equating to 1 Cal burned.

Well good :) I'm sure there have been some studies that have shown that. Can someone use the google and find them? Then we can end this thread.

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Co-host of the Ask a Cycling Coach Podcast

See my above post.

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You're going to have to go waaaaaaaaaaaaaaaay back to find the studies on human and mechanical work. I wanna way most of that stuff was done in the , 20s, 30s and 40s. Wanna look for work by guys like A.V. Hill.

All of the work on bikes will have been done on Ergometers...Monarchs were/are the most popular type, even in the 90s were where using rpms on a loaded flywheel to calculate the workloads, so we won't find really SRM, or that type of thing being used till very recently, and even then you'll still see it done the old way most of the time.

The study he cited gives him all he needs to know in this one sentence (Near the end of text)


John

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Top notch coaching: Francois and Accelerate3 | Follow on Twitter: LifetimeAthlete |

Would it be possible to wrap this thread up - it's no longer entertaining.

Thanks!

Predictable considering I was trying to talk about a subject of which I know nothing.

Of course it's not entertaining, now it's actually becoming educational.

John

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No, I gave you a choice between young vs. idiot. It seems you picked idiot, I cannot be responsible for your choices.



I understand some of the disconnect now. My contributions are not meant to be constructive and again, it is your choice to try to see them as such.

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I am going to have to start a new thread if the real issue is not addressed here:

Is walking one mile and running one mile equal in the required caloric expenditure?

Read this, I think it will help.

http://www.runnersworld.com/...4-311-8402-0,00.html

Hugh

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