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Why don't you contact him and get it then post it for all of us. I accept Dr. Cheung knows how to design a study and do the statistics such that the summary (abstract) reflects the reality.CoachFergie said:
seriously, you do not know what aerobic and anaerobic training is split 80/20?JamesCun said:
Indeed, yet you would rather stick with your bias than explore such a possibility for you
Perhaps. That is why no single study is perfect and needs to be repeated to confirm results and to check for alternative explanations. However, we expect this to be confirmed since individuals who have tested themselves have reported similar increases (over a longer period of time though) (see edit below).
Edit: Here are some test results done by a rider wanting to test our claims. Training was done exclusively on PowerCranks and testing was done just before starting PowerCranks training and at 6 and 13 months by a national team coach.
Results: pre 6mos 13 mos
VO2max (ml/min) 4692 5609 5794
VO2max (ml/kg/min) 71.2 81.7 85.5
FTP (W) 284 358 394
So, in 6 months he saw a 19.5% increase in VO2max absolute
a 14.7% increase in VO2max relative (weight must have gone up a bit) and
a 26% increase in FTP (starting out at 284 he was already at the pointy end of the amateur ranks I suspect). The coach told him after 13 months he was at a pro level and the only difference was he would not be able to recover as well as the younger folk.
you are free to contact the authors to see what you can get. Cheung is well known and available.
Frank, the fact that you are willing to use, promote and defend a study that has no available info or data is surprising. Seems you had these exact same discussions in 2007, with the same outcomes. Also strange that you feel the burden is on everyone else to back up your claims and track down the info. If I was promoting a product, I would hunt down the studies that supported it, not badger others to do that for me. Tells me that the real data isn't so supportive of PC usage...
The study abstract was made public at a national meeting and is available to anyone to use. I accept the findings as being true until someone shows they are not. Why wouldn't I use it, especially when it backs up what our customers report (although their results came a little faster than what our typical customer reports but I think they were more aggressive in their early training than our typical customer.) What can I say? I defend it because there is no evidence there is anything wrong with it. The fact you and others do not like the design (or the results) is not evidence there is anything wrong with what they did. And, the burden is on you, if you don't like the study results, to show they are wrong. I, for one, believe them until I am shown otherwise as they were accepted by the CSEP for oral presentation at their annual meeting. The fact I have been unable to get hold of the entire study, despite trying, does not invalidate the study nor the abstract/results published.JamesCun said:
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JamesCun said:
It's pretty simple, it's called running with the Hares and hunting with the Hounds. And it has nothing to do with science. Dixon is a poorly performed study. Acceptance for a conference means very little and lack of publication is very telling. Just another lame Frank Day story. A performance artist.
- Mar 18, 2009
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JamesCun said:
Not surprising at all. Frank is all marketing and no science. He wouldn't know science if it hit him over the back of the head with a baseball bat. Funny how Frank uses the same argument (bad study, poor design, etc) when the study results don't agree with his personal marketing strategies.
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LOL. It seems to me a particularly bad study design to test the usefulness of the cranks to use them part-time for 5-6 weeks when the manufacturer (me) says the typical new user doesn't start to see any real benefit until 6 weeks of exclusive use. You can argue that "I don't know science" if you want to but I do know my product and any such design is, most likely, only useful in proving our observation. You want benefits you need to use them a lot and for a pretty long time. I object to people claiming those studies disprove our 40% power improvement after 6-9 month exclusive use claim.elapid said:
I have no idea whether these things "improve performance" or not. However, for all the "scientist" out there, exactly how would you put a test together to determine whether they do "improve performance" or not?
Seriously, you have 100 riders use them? Then they either get better or they don't? Did they even try? Did they try to under perform on the first test to help improve their numbers later? Are you going to get race data from 100 pros so you know it isn't being gamed by the testers? (Yes, people change their performance when they are being tested -- as I am sure you "scientist" know.)
So, that is my question: What test (in detail) would satisfy the question of whether a particular training device actually improved performance? By "detail" I mean, sample sizes, study duration, control groups, controlled data (weather, fatigue, weight, caffeine, etc) -- you know all the stuff you "scientists" gather. Also, I want to know across all categories of riders -- so be sure to include details about how many Cat I, II, III, recreational, overweight, and obese individuals you have in each group. After all, a training device that is proven to work only with obese individuals is hardly of use for Cat I riders. Likewise, a device that works for Cat I riders may be of limited to no benefit to recreational riders.
Seriously, you have 100 riders use them? Then they either get better or they don't? Did they even try? Did they try to under perform on the first test to help improve their numbers later? Are you going to get race data from 100 pros so you know it isn't being gamed by the testers? (Yes, people change their performance when they are being tested -- as I am sure you "scientist" know.)
So, that is my question: What test (in detail) would satisfy the question of whether a particular training device actually improved performance? By "detail" I mean, sample sizes, study duration, control groups, controlled data (weather, fatigue, weight, caffeine, etc) -- you know all the stuff you "scientists" gather. Also, I want to know across all categories of riders -- so be sure to include details about how many Cat I, II, III, recreational, overweight, and obese individuals you have in each group. After all, a training device that is proven to work only with obese individuals is hardly of use for Cat I riders. Likewise, a device that works for Cat I riders may be of limited to no benefit to recreational riders.
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BikeGrip said:
Current state of play is no credible data has been presented so far. No study has shown by comparison to a control group that they improve performance.
Go to the start of this thread and there are several well performed studies published in quality journals that address this. Test before, have two groups carry out a block of training and test again. No differences in performances between the two groups, one training with independent cranks and one training without.
There are various checks and balances to all these points. In my research I did measure power from competition from 25 NZ national to international level riders and found the within-rider power from event to event was highly variable. Tactics, weather, road surfaces, gradients etc. Makes comparing events, even on the same course from day to day impractical.
Need to find a performance measure that has a good coefficient of variation so any change in performance measured must be beyond that level of variation otherwise the changes seen are just noise. Plenty of research models out there. Road cycling is hard because of the reasons above. My supervisor has done lots of research on sports like swimming and found very likely effects of things like caffeine on performance.
That is an excellent point. Original studies on products like dietary nitrates or beta alanine seemed to work on untrained or recreational athletes but as more work was done using high performance athletes the changes in performance were much less noticeable.
To sum the current state of play is that no claims made by the manufacturers of independent cranks have been supported with credible evidence.
Even non-credible evidence
There are lots of ways to run a study and to control for effort. And, it depends upon what you are trying to do. Let's take PowerCranks as an example. If you are simply trying to show that they work to improve performance for an equal amount of training not using them then you randomize your subjects to either use them or not. I have also considered that it might be useful to have a "placebo" group in that you put the big heavy PowerCranks on the bike but in dual mode and tell that group that these heavy cranks are designed to help the rider pull up on the back stroke. Then, you would have three groups. You could also have a partial use group, then you have 4 groups (this would let you test whether partial use can be as effective, assuming they work, as exclusive use). The more groups you have the more subjects you need, especially if the change one sees is small, and getting subjects is one of the more difficult aspects of a study. Then one can do the pre-testing. One good control regarding effort is to compare HR to the riders report of perceived effort. In general, HR correlates pretty well in any given person to their relative effort and their perception of effort such that if my max HR pre testing is 160 and it is 180 post testing then we can presume they were dogging it the first test. But, if it is 168 first test and 169 second test we can presume the efforts were similar. Then you can have each individual keep a training log, trusting them to be honest regarding their usage (most people are). Or, you can have them do all of their training in the lab on the lab bike where time and intensity can be measured but trusting them to not do anything outside of the lab. Then you do your post testing after they have completed the test intervention. Once all the data is gathered then one does the statistical analysis and then one tries to interpret what it all means. For instance, if one sees a trend but the data doesn't reach statistical significance one might conclude that even though this data doesn't demonstrate a difference that another study that either lasted longer or had more people might demonstrate a difference. This helps the next researcher design a more powerful study that might uncover and demonstrate there is, indeed, a difference.BikeGrip said:
There are a lot of everyday issues that go into designing a study. What kind of subjects do I want? It is easier to show a benefit in novices so less people and time may be needed for the study but it would mean more to the elite cyclist if a benefit were shown in elite cyclists. How many subjects can you get that fit your definition of subject type? 100? Can you get 100 sets of PowerCranks? 2? is that going to give you a good statistical sample? 6? 6 might work but can you expect to see a difference in the amount of time you have allotted? And, then, what do you do when someone drops out? Speaking of time, how much time do you have. Do you have to do the whole thing in one semester, one year, or what? How much will it cost? Where will the money come from? etc. etc.
I am sure elapid, with his self stated expertise on study design will correct me where I am wrong and expand on what is necessary to help you out here. But, to answer the last part of your question, to answer the question for all of those categories really requires a separate study for each category. My guess is if one could get a study done that showed a benefit on elite riders one could presume that it would work on all the lesser category of riders also. But, where does a researcher find a large enough group of elite riders in their little neck of the woods willing to stop what they are doing to participate in some lame study? Maybe now you are beginning to understand why there are so few studies that actually demonstrate a benefit to anything we do or use?
- Mar 10, 2009
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BikeGrip said:
Others have given thoughts on that, but consider for a moment the claims being made by Frank on his website for many years.
2005:
2008:
2011:
2012:
Today:
Since the 2-3 mph improvement claim is the most consistent one used, let's stick with that.
That would mean a regular Cat 2 could become a grand tour winning rider. It's just nonsense of epic proportions.
Or to put that into power terms for a rider + bike of 77kg, average CdA in the drops and rolling resistance on flat road, no wind:
A 2W/kg rider would need to increase power by 31% - 49%.
A 3W/kg rider by 27% - 43%
A 4W/kg rider by 25% - 39%
A 5W/kg rider by 23% - 36%
Now those are impressive numbers. Frank has himself on many occasions claimed a 40% improvement in power value and we can see it on his own website at times.
And no one says such an improvement is not possible through training, better aerodynamics and other means of reducing resistance forces, especially if you are unfit or untrained to begin with.
The question however is whether such an improvement (any improvement) in speed and/or power is due to the cranks and would be over and above that attainable training on regular cranks.
So far that has not been demonstrated to any degree, let alone enabling a rider to add 2-3 mph to their speed.
If it had we would be seeing trained Cat 4 power crankers winning Cat 1 races, trained Cat 2 power crankers riding Pro Tour riders off their wheels, and so on. It's just a load of nonsense.
"Extraordinary claims require extraordinary evidence" - Marcello Truzzi
Coach, Alex, et al. Thanks for the input and good points... For Coach, I had looked at some of the studies you posted originally (there a quit a few). Essentially, some of these so called "scientific" studies seem a little pointless to me.
For instance, the "Training With Independent Cranks Alters Muscle Coordination Pattern in Cyclists Fernández-Peña, Eneko1,2; Lucertini, Francesco1; Ditroilo, Massimiliano1,2" study.
Ok, the conclusion...." The results provide scientific support for muscle coordination pattern alteration from the use of IC, potentially achieving a more effective pedaling action."
Hmm.. Sounds good. But the study looked at 60 second periods at 30-50% of max power. I don't really see the functional use for this. First, it would depend on how "max power" was obtained. Perhaps this "maximal pedaling test" is a standardized test or the exact details were given in the full article, but even if it were, the 60 second time period is also highly suspect. So, I pedal better for 60 seconds, then what? I am not that fast to finish my TT in 60 seconds -- but hey, I ride a Giant, so I am slow.
I could go through more, but it seems we agree on the conclusion ... "Nothing to see here" -- my issue is that it just seems that constructing any test that would be worth seeing would be extremely costly. Given that there is no patent protection for this rather simple device that has been around for decades, no company has any incentive to invest the type of money required to prove it. Even if a company did, then any other company could then come along and market the "scientifically proven" IC system without having to recover any costs from an expensive trial.
This actually leads to an interesting economic result... companies with products that actually work (but are not subject to patents) have an incentive NOT to publish scientific evidence that conclusively proves their claims. As Alex points out that, if it actually worked, then everyone would use it. While true, it would also be true that everyone would sell them -- because the market is the entire biking community. Instead, a smaller company would be far more profitable to make vague unsubstantiated claims or reference vague and inconclusive "studies" and then rely on its marketing and distribution channels to generate profits (which is how 99.9% of any sports/fitness companies make their money.) As soon at it is established that the device is universally a good thing, then sales and marketing become irrelevant and manufacturing and economics of scale dominate -- which would favor large established companies.
It would also seem that for independent cranks, a "placebo" control group would be impossible -- I don't think Frank's idea would fool too many people. As these tests generally run fairly small sample sizes (10-20), it would seem that one or two fanatics (on either side) could skew the results.
Obviously, as Alex points out, anyone can make unsubstantiated claims and if someone is promising me a "40% power increase," I offer them this bridge in Brooklyn in exchange for the cranks. I certainly am not saying these claims are remotely true -- just that I understand why no substantiated claims exist. (and it is not necessarily that the cranks simply don't do anything).
For instance, the "Training With Independent Cranks Alters Muscle Coordination Pattern in Cyclists Fernández-Peña, Eneko1,2; Lucertini, Francesco1; Ditroilo, Massimiliano1,2" study.
Ok, the conclusion...." The results provide scientific support for muscle coordination pattern alteration from the use of IC, potentially achieving a more effective pedaling action."
Hmm.. Sounds good. But the study looked at 60 second periods at 30-50% of max power. I don't really see the functional use for this. First, it would depend on how "max power" was obtained. Perhaps this "maximal pedaling test" is a standardized test or the exact details were given in the full article, but even if it were, the 60 second time period is also highly suspect. So, I pedal better for 60 seconds, then what? I am not that fast to finish my TT in 60 seconds -- but hey, I ride a Giant, so I am slow.
I could go through more, but it seems we agree on the conclusion ... "Nothing to see here" -- my issue is that it just seems that constructing any test that would be worth seeing would be extremely costly. Given that there is no patent protection for this rather simple device that has been around for decades, no company has any incentive to invest the type of money required to prove it. Even if a company did, then any other company could then come along and market the "scientifically proven" IC system without having to recover any costs from an expensive trial.
This actually leads to an interesting economic result... companies with products that actually work (but are not subject to patents) have an incentive NOT to publish scientific evidence that conclusively proves their claims. As Alex points out that, if it actually worked, then everyone would use it. While true, it would also be true that everyone would sell them -- because the market is the entire biking community. Instead, a smaller company would be far more profitable to make vague unsubstantiated claims or reference vague and inconclusive "studies" and then rely on its marketing and distribution channels to generate profits (which is how 99.9% of any sports/fitness companies make their money.) As soon at it is established that the device is universally a good thing, then sales and marketing become irrelevant and manufacturing and economics of scale dominate -- which would favor large established companies.
It would also seem that for independent cranks, a "placebo" control group would be impossible -- I don't think Frank's idea would fool too many people. As these tests generally run fairly small sample sizes (10-20), it would seem that one or two fanatics (on either side) could skew the results.
Obviously, as Alex points out, anyone can make unsubstantiated claims and if someone is promising me a "40% power increase," I offer them this bridge in Brooklyn in exchange for the cranks. I certainly am not saying these claims are remotely true -- just that I understand why no substantiated claims exist. (and it is not necessarily that the cranks simply don't do anything).
I think it is clear that designing and completing scientific studies that involve many variables and require substantial time to demonstrate are extremely difficult to design and complete. Those who demand same are doing so knowing that it is almost impossible to do. Knowing that such a study is unlikely to appear they can feel smug in their accusations that the lack of a study proves our claims have no basis while choosing to ignore the scientific and anecdotal evidence that does exist that supports the device. I presume further studies will continue to happen and maybe a study like Dixon will happen with a "proper" control group (one these guys understand) with convincing results, although I don't think anything can change there mind. We will, I guess, continue to be stuck selling to those willing to take a "leap of faith" to see if they do anything for "you". Maybe the new devices that measure technique will convince these folks that technique really does matter.BikeGrip said:
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FrankDay said:
On the issue of studies presented at conferences vs actually published after peer review, here's what Dr Larry Creswell had to say on that, with respect to a different study where many of the original presentation conclusions were overturned once it went through a peer review process.
From this item.
- Apr 21, 2009
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BikeGrip said:
Point of the study was to show that independent cranks use change the pattern of force application around the pedal stroke and secondly that when riders changed back to normal cranks the pattern rapidly reverted to normal.
How do you define worth seeing. The studies are pretty clear cut. Frank flip flops about study length to suit. But there are some 10 week training studies there. If you can't get an improvement after 10 weeks there really is "nothing to see". Humans learn pretty quick and adapt really fast. Most supplement studies find an meaningful effect and most interval strategies show a meaningful effect in far less time.
It's a moot point, Frank has already said 40% is a made up number for marketing purposes and he chose it because saying a 5-10% wouldn't have the same impact.
Probably find other marketers don't see the potential. Also considering the continual lies from Frank about the product I'm not surprised.
Quite the opposite. More incentive to do in house research to keep finding a point of difference and keep chasing the marginal gains.
Ummm, tell that to the marketing departments at Coca Cola, Nike and MacDonalds.
Andy Coggan pointed out something similar several years ago. Makes for a pretty boring time in the control group which should favour the experimental group.
It's a meaningless claim. If you had real data you would share it. Fortunately there are too many people here who have real good BS detectors.
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Alex Simmons/RST said:
Matches my recent experiences. As I said I would not expect 95% of the presentations from WCSS to find their way into a quality journal.
That is one of the most nonsensical inferences ever in view of the fact that current grand tour winners are using the product. How on earth do you expect a cat 2 rider to suddenly become the equivalent of a grand tour winner by suddenly training with a device the grand tour winner is already using? Now that is not to say that a Cat 2 rider couldn't improve enough in one season to become a pro because it has happened. I think all you could reasonably say is that a 2-3 mph improvement is likely to get the user a lot closer to the grand tour riders but not good enough to make the team or win the race.Alex Simmons/RST said:
Yes, let's look at those numbers for a 70 kg rider and assume those are max efforts. First notice that it takes a smaller percentage increase for the faster rider to see a 2-3 mph increase. But, of course, the slower rider is starting at a lot lower power so improvement should come easier, to whit:
2w/kg rider is generating 140 watts, 31% gets him to 183 Watts, that doesn't sound so difficult does it?
3W/kg rider is generating 210 watts, 27% gets him to 266 Watts, again doesn't seem so impossible, or even very difficult.
4W/kg rider is generating 280 watts, 25% gets him to 350 watts, more difficult but many can do that.
5W/kg rider is generating 350 watts, 23% gets him to 430 watts, while large, hardly a threat to a TDF sprinter who may be generating 1250 watts.
If you are talking FTP, these are still not impossible numbers (although 5w/kg is really hard to sustain for an hour but I suspect there might be a few who could do it) but the issue then becomes one of endurance, how long can they maintain the new number. It takes longer to achieve sustainable increases for endurance efforts than to simply see increases for shorter efforts. With enough time short effort increases should translate to equivalent longer effort increases. Another reason new users are not a threat to win the TDF.
So, lets compare those numbers with what has been demonstrated.
Phil Holman increased his top speed on the track from 35 to 38 mph in 7 months. Using a frontal area of 0.4 and a RR of .001 analytic cycling says this is a power improvement from 481W to 614 watts (28%). (And he won a bronze medal at worlds.) Not bad for a 7 month effort.
Then the rider previously posted who increased his professionally tested FTP in 1 year from 284 to 394 (38%) an increase in w/kg from 4.3 to 5.81.
Or, the triathlete who reported seeing his speed for a 12 mile look improve from 20 to 25 mph in one season. A calculated power increase from 136 watts to 248 watts, an 80% increase.
Such reports occur all the time.
No one would claim that the three examples above were unfit or untrained to begin with, would they? And, being experienced racers all of them it is unlikely any changed their aerodynamics substantially, at least none reported such change, attributing all the change seen to the PowerCranks. Such improvements happen all the time.
While it has not been scientifically proven that such improvements are due to the use of the cranks, it is the assessment of those using the cranks that the cranks were the proximate cause of the big improvements they saw. None of these observers have anything to gain from these reports. Why do you, someone with zero experience with the product, find them so unbelievable, other than the improvements are so large they must be lying?
Nope, will never happen. Some have managed to fulfill their dream of becoming a pro after getting on PowerCranks but such changes in someone training 8-10 hours a week will never overtake the base and experience of a pro tour rider with years of training 20 hours a week. Expecially, when the pros are using them also. There is more to getting really really good than simply slapping PC's on your bike.
Yep, and the evidence for most of our customers is what they experience for themselves. Beats anything they can read in a journal somewhere.
One last thing, the original question asked how one might construct a study, and you answer him by being critical of my claims as if they are so outlandish a study isn't necessary. The problem is that independent people actually report such results. An independent study is necessary to understand if their observations are correct or not. But it is clear you have no interest in helping him to design one or understand how one might design one. Just stay on point, attack Frank, seems to be your theme.
You do know that Computrainer offers a Performance Improvement Guarantee, improve 10% in 5 months or your money back? Do you know if that claim is backed by any credible evidence? They are the only other company that makes any kind of performance improvement claim that I know of yet I am unaware of any scientific data that supports their statement. I suspect they are simply comfortable that they have enough internal data to support that guarantee. It is the same with us.CoachFergie said:
Really, is that what he said? Wonder then why they showed up on his bike at training camp? And, even if so, so many other TDF and World Champs have and do use them that it really doesn't matter.elapid said:
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