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#21
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Beware of PowerCranks
On Jun 3, 7:58 pm, "Phil Holman" piholmanc@yourservice wrote:
I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. http://powercranks.com/assets/pdfs/C...dixon_2006.pdf Luttrell and Potteiger found no difference in VO2Max. |
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#22
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Beware of PowerCranks
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#23
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Beware of PowerCranks
wrote in message ups.com... On Jun 3, 7:58 pm, "Phil Holman" piholmanc@yourservice wrote: I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. http://powercranks.com/assets/pdfs/C...dixon_2006.pdf Luttrell and Potteiger found no difference in VO2Max. That group trained for 3 hours per week at 70% of VO2Max for 6 weeks versus 8 hours per week (20% anaerobic) for 6 weeks. The second test was considerably more extensive. There was also no control group for the second test. What does it take to get an appropriate and properly designed test? Max sums it up well.......Dr. Testa was quick to indicate that a fully controlled study is still needed, but that preliminary impressions from several high caliber athlete's had been very positive. With riders like Danielle Nardello and Stefano Garzelli liking the results and producing more even power output from using them. He had also seen some 25 - 30 watt gains at LT (lactate threshold) in people using them for the first time, but also said that other training stimulus were present. He calls them a "very valuable tool" and something that forces everyone, pro's and amateurs alike, to be more efficient by forcing you to carry the weight of the up stroke leg and also maintain force through the entire range of motion. "It's something that nothing else forces you to do and it makes you do work that is without a doubt of benefit."" Phil H |
#24
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Beware of PowerCranks
On Jun 3, 10:02 pm, "Phil Holman" piholmanc@yourservice wrote:
There was also no control group for the second test. What does it take to get an appropriate and properly designed test? On the one hand, I'd say this is like Keystone Kops. On the other, I'd have to admit that I've read some pretty bad manuscripts in my own field, and I'm often surprised at how clueless supposedly smart people can be about what constitutes a properly designed test. |
#25
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Beware of PowerCranks
In article ,
"Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. |
#26
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Beware of PowerCranks
"Tim McNamara" wrote in message ... In article , "Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. I'll assume you are talking about a theoretical ceiling and not the difference in the same athlete being in shape and not in shape. The theoretical ceiling is biologically determined but what biologically constitutes that ceiling is still up for discussion. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. I thought you of all people could separate the science from the emotion. Phil H |
#27
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Beware of PowerCranks
On Sun, 3 Jun 2007 13:45:35 -0700, "Phil Holman"
piholmanc@yourservice wrote: "Tim McNamara" wrote in message ... In article , "Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. I'll assume you are talking about a theoretical ceiling and not the difference in the same athlete being in shape and not in shape. The theoretical ceiling is biologically determined but what biologically constitutes that ceiling is still up for discussion. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. I thought you of all people could separate the science from the emotion. Phil H Dear Phil, I'm skeptical (as you've noticed), but I also suspect that my skepticism gets in the way of understanding. So here's a dumb question . . . Is the claimed improvement for PowerCranks thought to be due to a mostly physiological change, very roughly the equivalent of bigger biceps letting you lift a larger weight? Or is it due to a mostly mechanical change in technique, with the rider's body left unchanged and the improvement due to the rider learning to use the same muscles in a more efficient manner? My assumption was that it's supposed to be a raw physiological improvement, but maybe I've been missing the point and technique is supposed to play a major role. Cheers, Carl Fogel |
#28
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Beware of PowerCranks
wrote in message ... On Sun, 3 Jun 2007 13:45:35 -0700, "Phil Holman" piholmanc@yourservice wrote: "Tim McNamara" wrote in message ... In article , "Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. I'll assume you are talking about a theoretical ceiling and not the difference in the same athlete being in shape and not in shape. The theoretical ceiling is biologically determined but what biologically constitutes that ceiling is still up for discussion. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. I thought you of all people could separate the science from the emotion. Phil H Dear Phil, I'm skeptical (as you've noticed), but I also suspect that my skepticism gets in the way of understanding. So here's a dumb question . . . Is the claimed improvement for PowerCranks thought to be due to a mostly physiological change, very roughly the equivalent of bigger biceps letting you lift a larger weight? Or is it due to a mostly mechanical change in technique, with the rider's body left unchanged and the improvement due to the rider learning to use the same muscles in a more efficient manner? My assumption was that it's supposed to be a raw physiological improvement, but maybe I've been missing the point and technique is supposed to play a major role. Two things: Elimination of pedaling inefficiencies Increased aerobic capacity due to greater muscle utilization. Both of these are subject to the same adaptation of pedaling technique and in my case, required substantial training hours to realize the adaptation. Mostly in the form of conditioning the hip flexors and hamstrings to pull up. Your previous mention of the placebo effect is interesting. It "may" work for determining VO2Max or Maxpower where the subject was less than motivated and pooped out early on the "before" test. However, I don't see how a placebo effect can explain a change in gross efficiency. Phil H |
#29
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Beware of PowerCranks
On Sun, 3 Jun 2007 14:50:21 -0700, "Phil Holman"
piholmanc@yourservice wrote: wrote in message .. . On Sun, 3 Jun 2007 13:45:35 -0700, "Phil Holman" piholmanc@yourservice wrote: "Tim McNamara" wrote in message ... In article , "Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. I'll assume you are talking about a theoretical ceiling and not the difference in the same athlete being in shape and not in shape. The theoretical ceiling is biologically determined but what biologically constitutes that ceiling is still up for discussion. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. I thought you of all people could separate the science from the emotion. Phil H Dear Phil, I'm skeptical (as you've noticed), but I also suspect that my skepticism gets in the way of understanding. So here's a dumb question . . . Is the claimed improvement for PowerCranks thought to be due to a mostly physiological change, very roughly the equivalent of bigger biceps letting you lift a larger weight? Or is it due to a mostly mechanical change in technique, with the rider's body left unchanged and the improvement due to the rider learning to use the same muscles in a more efficient manner? My assumption was that it's supposed to be a raw physiological improvement, but maybe I've been missing the point and technique is supposed to play a major role. Two things: Elimination of pedaling inefficiencies Increased aerobic capacity due to greater muscle utilization. Both of these are subject to the same adaptation of pedaling technique and in my case, required substantial training hours to realize the adaptation. Mostly in the form of conditioning the hip flexors and hamstrings to pull up. Your previous mention of the placebo effect is interesting. It "may" work for determining VO2Max or Maxpower where the subject was less than motivated and pooped out early on the "before" test. However, I don't see how a placebo effect can explain a change in gross efficiency. Phil H Dear Phil, Assume that the small claimed improvement in gross efficiency is indeed real (or any other measurements). This real (not placebo) improvement could be the result of equal efforts in training, with one training method recruiting new muscles. The improvement would depend on the specific training method--no PowerCrank, no improvement. But the real improvement might also be the result of a placebo/new-toy effect causing one group to train harder during the same number of hours, not the recruitment of new muscles. The improvement would depend not on the specific training method, but on getting the subjects in one group to concentrate and train harder--PowerCrank, electric shocks, Playboy models with whips, anything would work. Either way, tests will show physiological improvement. My question is whether the improvement is due to something making the riders concentrate more on their training sessions (psychological improvement leading to more intense physical training and thus to improvement) or due to something that's purely physical (no extra concentration during training). As a rough analogy, I know that I can improve my daily ride times just by finding something that makes me pay more attention. Put a pretty girl in front of me, and I'll concentrate on keeping her in sight. Given a six-week supply of pretty girls to try to catch, I'll probably be in better shape than my twin brother, who rode the same route, even though neither of us had PowerCranks--I'd just be training harder. I gather that Tim expects some physiological limits to be unaffected by training--that is, the only way for me to match Lance on some measurements such as VO2 would be for me to pick different parents. And it's worth pointing out for anyone reading that most of the low hanging fruit in the training regimen orchard has already been picked. On the one hand, this means that we're unlikely to see anything except small and hard-to-prove improvements, so things like PowerCranks are going to be tough to demonstrat--very small increases are hard to separate from random variation and confounding factors. On the other hand, it also means that larger and larger claims for improvements are going to be harder and harder to believe. Increases of 11% and 15% should either sweep the bicycle racing world like wildfire, or else turn out to be bad science. Unfortunately, the scientific record is littered with the corpses of small, exciting studies that turned out work only when they were small or conducted by particular researchers. Despite our natural suspicions, no dishonesty is required to arrive at grossly mistaken results: http://skepdic.com/blondlot.html The N-ray scientists were working with something far more cut and dried than physiology and athletic training, where the opportunities for deluding ourselves and failing to notice confounding factors are legion. But it would be fun to find out that my skepticism is mistaken. Cheers, Carl Fogel |
#30
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Beware of PowerCranks
In article ,
"Phil Holman" piholmanc@yourservice wrote: "Tim McNamara" wrote in message ... In article , "Phil Holman" piholmanc@yourservice wrote: wrote in message ups.com... On Jun 3, 5:46 am, wrote: On Sat, 2 Jun 2007 19:39:13 -0700, "Phil Holman" Frank Day. His last posts here were after a scientific study showed a statistically significant 1.5% gross efficiency improvement. The experts here still wouldn't buy it. No offense, but that sounds like 200 watts rising to 203 watts. Well, the difference was in gross efficiency, not in power. Frank Day calls them PowerCranks, not EfficiencyCranks. Phil may know whether there has been a published RCT that shows an increase in power. I just checked their website and found another study of trained cyclists that showed a 15.6% increase in VO2max and an 11.6% icrease in max power. My understanding- which may not be correct- is that VO2 max is biologically determined and that training does not significantly change this. I'll assume you are talking about a theoretical ceiling and not the difference in the same athlete being in shape and not in shape. The theoretical ceiling is biologically determined but what biologically constitutes that ceiling is still up for discussion. As I understand it (it's been a while since I had any reason to look into this stuff and maybe new data has come to light in the interim), if your VO max is 60 ml/kg/min then that is basically it. You can't "train up" your VO2 by 15.6% at least from the data I had looked at a few years back. Miguel Indurain's published VO2 max was 88 ml/kg/min which is very much at the high end. Lemond's was reported to be over 90 ml/kg/min. A training technique that would net guys think this a 15.6% increase would make them invincible. Nobody could touch them in an event like the Tour de France. You can't get even those kinds of gains by doping. There are things you can train up by quite a bit, such as your sustained power output at lactate threshold, Wingate test, etc. Those things are important and can make a big difference in race results. PowerCranks have always been marketed a bit too much like the Second Coming for my tastes. I thought you of all people could separate the science from the emotion. Hype annoys me, what can I say. When the hype seems mighty unrealistic, I get suspicious of there being a dose of snake oil in the mix. IMHO people who are extremely competitive have a tendency to be a bit gullible when it comes to things that promise improved performance. Of interest to me would be whether whatever benefits are gained from PowerCranks are durable. When people go back to regular cranks for racing, do the maintain the neuromuscular pattern that a PowerCrank is supposed to develop? Or do they go back to normal riding quickly? Do they have to "brush up" with the PowerCranks periodically? My hunch is that the muscle recruitment pattern is quickly unlearned and the rider goes back to a normal pedal stroke within a week or so after returning to using normal cranks. |
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