Facts, Not Fiction

 
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    #41
    Quote Originally Posted by Atticus View Post
    We'll agree to disagree. My expertise is in semantics, and I am certain that the term "4% energy return", though very meaningful to the engineers who designed it, is a meaningless term in any real-world application.
    It's meaningless to you because you have no idea what the people who coined it mean by it, nor have you indicated any interest in asking them. You aren't speaking for anyone but yourself.

    It's actually fascinating that you're not an engineer, or a scientist, or a shoe developer, and yet you're bold enough to say it has no real-world application.

    I like to ask the people who know about these things before I go asserting that something is useless, when in fact I know next to nothing about the problem at hand. Then I don't end up sounding like a know-it-all who actually knows nothing.
    Last edited by trackCanuck; 10-17-2019 at 12:20 AM.
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    #42
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    Quote Originally Posted by trackCanuck View Post
    It's meaningless to you because you have no idea what the people who coined it mean by it, nor have you indicated any interest in asking them. You aren't speaking for anyone but yourself.
    Speaking of which . . . you are assuming I didn't do MY homework. Which, of course, I did. Here's a representative article:

    https://www.runnersworld.com/news/a2...-percent-work/

    An excerpt:

    The same University of Colorado Boulder researchers who verified the 4 percent claim of the Vaporflys examined what a 4 percent energy savings would mean for runners of different sizes and speeds. Through whole bunch of theory and math—which they just published in Frontiers in Physiology—they determined that the relationship between improvement in running economy and speed is not linear—that is, saving 4 percent energy does not necessarily mean you’ll run 4 percent faster. . .
    For instance, a 4-hour marathoner who saves 4 percent energy will run 4 percent faster (9 minutes and 36 seconds, or a 3:50:24 marathon), whereas a 2-hour marathoner will run only about 2.5 percent faster (3 minutes, or a 1:57:00 marathon).
    I do believe they did their math due diligence, and in mathematical theory, this is all well and good. But if EK got a 3-minute help from the shoes, PLUS the minutes he saved from the perfect conditions, pacing, and air-blockers, we should have seen 1:55, to which you say, well maybe he COULD have, if the pace asked for it, and then I say, but he didn't. We have fact and then we have conjecture. I am a born skeptic. When he runs the 1:55, I will apologize and admit my premise flawed. Your mileage may vary (which is also my point).

    You can keep calling me a dunder-head, but I did do the homework. I just remain unconvinced of the value of the term '4% less energy' in the real world of the stop-watch. I apologize if this really upsets you.
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    #43
    Athletes mention the "trampolining" affect from the Vaprofly shoes. The newest version has a separation between back and front half of the sole. It also looks thicker than earlier models. If the shoes move from 3% to 5% (to 10% !) as the soles get thicker and technology improves, then should they be banned ?
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    #44
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    No....
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    #45
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    The ghost of Abebe Bikila wants to know why the pansies of today need to wear shoes at all.
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    #46
    This feels like the nonsense with the green catapoles in 1972. Those poles were available to any athlete who wanted to use them.
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    #47
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    Quote Originally Posted by steve View Post
    Serious question. Is there good evidence anywhere that doping in the modern era with the guidance of health care professionals (like Ben Johnson, Marion jones, Lance Armstrong, A-Rod, etc.) has negative health effects?
    Does dying count as a negative health effect. A few years back there were a number of deaths from heart issues in cycling, and that was with testing etc.

    One problem that a lot of people seem clueless about is that allowing doping leads to a race to the bottom. If A takes X units of EPO, B might want 2X, and C wants 3X, etc. EPO will definitely kill you if you take too much because the blood is too thick.
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    #48
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    This part is just wrong, mainly irrelevant

    they determined that the relationship between improvement in running economy and speed is not linear—that is, saving 4 percent energy does not necessarily mean you’ll run 4 percent faster. . .
    Being linear does not make a 4% energy gain translates in to a 4% faster speed. It could be linear and have a 4% gain result in a 0.1% increase in speed, just so long as a 5% energy gain results in a 0.125% gain in speed.

    The example that is then given is a non-linear case, but they do not actually provide anything in that quote that says how non-linear it really is. More importantly it does not give a translation of what it means for a 12mph or a 13mph marathon. Also, it can be non-linear but the curvature is so small as to not matter much. Gravity leads to massive objects 'bending' a light beam but this effect is small for earth and minuscule for the moon, and even more minuscule for a third of Saturn's moons (20 just got added to the tally that now is 81 and the new ones are about 5km in diameter).
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    #49
    Quote Originally Posted by 26mi235 View Post
    Does dying count as a negative health effect. A few years back there were a number of deaths from heart issues in cycling, and that was with testing etc.

    One problem that a lot of people seem clueless about is that allowing doping leads to a race to the bottom. If A takes X units of EPO, B might want 2X, and C wants 3X, etc. EPO will definitely kill you if you take too much because the blood is too thick.
    I thought that was with blood doping in dutch cyclists in the '80s and not with EPO use under a physician's guidance. Regardless, I'm looking for evidence in scholarly articles or even good anecdotal reports. I'm finding position statements that admit more research needs to be done, and speculation that PEDs are safe to use, under certain controls, to improve performance. Essentially, a lot of talk without a lot of evidence.

    I'm personally against PEDs in part because of my perception that they cause harm. When discussing it outside this forum, I had to admit that I had no good evidence for that stance when they are used under good supervision. It's still cheating based on the rules and all sports have rules that are important to follow, so I'm still against them, but the negative hearth benefits don't seem to be there in the way I thought they were.
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    #50
    It would indeed be absurd to conclude that a "4% greater energy return" translates into 4% greater speed. Men's legs are over 40% stronger than women's, even at the same bodyweight, but men only run 10-12% faster than women.
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