[reply]This is a very telling statement. It amounts to hearsay. How can he "confirm" they were "good" cyclists? Define "good". Also, saying that you met the PC user in Hawaii, it hints that perhaps this user is a triathlete, and the fact that said person knows 2 of the participants could imply that those 2 participants were also triathletes as opposed to strictly road racers. In my opinion, triathletes tend to have more room to grow in terms of VO2 than road racers since that is not a highly trained aspect for their events.

The abstract does not say what the exact training protocol was. It is quite possible that the study used a mix of athletes, some of whom who were triathletes with relatively poor VO2 compared to their capability, subjected the subjects to VO2 and anaerobic levels (all we know is the 80/20 split of aerobic/anaerobic, not the exact protocol), and improvement was found. If you take athletes who have not been working on level 5 and up and put them on an appropriate protocol, you will see improvement.

I consider myself highly trained on the bike (somewhere around 600 hours on the bike in the last year) and have relatively good VO2 power compared to functional threshold. But I'll be the first to admit that if I've been doing a ton of L4 and below, those first few weeks of VO2 training kick my butt. I routinely see at least a 5% increase in VO2 power in just a couple of week and depending on where I was, as high as 10%. I'm sure if you took a look at me now, I could easily gain 10-15% VO2 - a dedicated block of time for anaerobic only to be injured, off the bike for a week, and struggling to even finish a 5 minute interval at my previous threshold. I'm highly trained, but I came into late October with a slight deconditioned state and different focus. As Andy would say - specificity, specificity, specificity. If you haven't been training VO2, you can easily increase it by over 10% in season no matter whether you use regular or power cranks.[/reply]

Of course the abstract does not say what the exact training protocol is, it is an abstract. I agree, the devil is in the details. Like those who try to say that the Coyle study "proved" that it is better to just push harder. That paper did no such thing.

Anyhow, the person in question just happened to win his age group so i suspect he has some sense of what constitutes a "good" cyclist from a triathlete "poser". But, I am sure the study didn't consist entirely of TDF participants so "good" is relative. One more anecdote. When I was at Canada someone working the Adidas booth came up to me all effusive. Turns out he was given a pair of PC's by the coach at the National Training Center in Victoria (this is the cycling national team, not the triathlon) and he was very happy about his improvement. We had just received this abstract so I told him about the study and asked him to predict how much power they gained and how much it showed VO2 max had increased. He said 100 watts and 15%
VO2 max. I asked him why he chose those numbers and he said "because that is what I saw".

Regarding your contention it is "easy" to improve VO2 max in 6 weeks (on 8 hours a week of training no less), given the right circumstances, in trained people. Show me the study that proves this. Without that your contention is pure speculative hogwash in my opinion.

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Frank,
An original Ironman and the Inventor of PowerCranks

 
A starting VO2max of 58.1 (and lower!) is hardly enough to cause me to "believe" they were "highly trained." I'm in the category of "hardly trained" and my VO2max is higher than that.[/reply]

BINGO!! These are probably not in season highly trained cyclists.

[reply]Frank,
Any chance you have one of the authors email addresses so we could contact them for more info about the study?[/reply]

I don't have them where I am. Stephen Cheung though can be reached through Pezcyclingnews, as he writes many articles for them.

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Frank,
An original Ironman and the Inventor of PowerCranks

[reply]
Stephen J. Dixon, Michael F. Harrison, Kenneth A. Seaman, Stephen S.Cheung and J.Patrick Neary. University of New Bruswick, Fredericton, NB; Dalhousie University, Halifax, NS; University of Regina, SK , presented at the Canadian Society for Exercise Physiology (CSEP) Nov 3, 2006

Physiological responses to training using PowerCranks on trained cyclists

ABSTRACT

PowerCranks? are cycling cranks that are independent of each other, requiring force application throughout the pedal stroke, theoretically increasing muscle recruitment and stimulus in the legs. This study examined the physiological adaptions to PowerCranks, and the time course of responses in maximal and submaximal cycling performance. Eight Trained cyclists (35.1 ± 6.8 yr) participated in 6 weeks of 100% immersion training using solely PowerCranks, consisting of ~8 h/wk of aerobic and anaerobic (~80:20) cycling training. A continuous incremental cycling test to exhaustion (50 W increase every 2 min) was performed prior to and following the training program using normal cranks. In addition, 10 min of submaximal cycling (70% of VO2max wattage) were performed with both normal cranks and PowerCranks at an approximate cadence of 85 rpm, pre and post training. VO2max increased 15.6% (58.1 ±5.8 to 67.3 ± 6.6, P=0.013), Maximum power increased 11.6% (316.7 ± 25.8 to 358.3 + 20.4, P=0.011) following PowerCranks training. In summary, our data suggest that PowerCranks increased maximal aerobic capacity and power in trained cyclists. [/reply]



Frank this has nothing extra to offer. I agree with the 11 % power increase and can explain in detail how training with your cranks creates this extra power. Why did the Luttrell study find no change in VO2MAX ?

I must say, I enjoy your style of debate: come up with a faulty conclusion that is the very definition of confirmation bias, then, when called on it, change the subject to someone else's interpretation of a different study--pile on some anecdote, and voila!

Do you understand why it's difficult for so many people to take you seriously?

If you read the Luttrell study you will find they didn't look for it. They measured VO2 max at the beginning of the study so they knew where 69% of VO2 max was for their testing. They then tested at the beginning and after the test period at this power level for an hour. The study design was to look at cycling efficiency primarily, not maximum power.

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Frank,
An original Ironman and the Inventor of PowerCranks

I have contacted the guy (stephen.cheung@dal.ca) and asked him for a reprint. I will post it and a review as soon as I've got it.

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Francois-Xavier Li @FrancoisLi
"We don't stop playing because we grow old; we grow old because we stop playing." George Bernard Shaw
http://www.swimrunfrance.fr
http://www.worldofswimrun.com

I've just ready your bio and you are a really impressive guy. I find it hard to believe that someone with an engineering background from the USNA, and an anesthesiologist MD, would not have more of a critical viewpoint of the study. Clearly from your experience as an anesthesiologist you would understand that any intervention whether a drug or the use of power cranks must be tested against a control group to tease out the various interactions. Most pharmaceuticals for instance are not just tested to see if they work, they are tested to see amongst other things, whether they work better than placebo, or work better than an alternative drug. Obviously, in the case of the power cranks the study of interest would be whether power cranks works better than regular cranks. Now better can mean a variety of things, but I think for most triathletes, better would equate to increasing sustainable power, i.e. LT Power.

The abstract that you posted merely shows that exercising 8 hours a week improves various metrics of fitness. This is not ground breaking. The most that can be "proven" from reading the abstract is that exercising with Power Cranks leads to some fitness gains, whether this is more, less or the same as with regular cranks cannot be determined.

[reply]I've just ready your bio and you are a really impressive guy. I find it hard to believe that someone with an engineering background from the USNA, and an anesthesiologist MD, would not have more of a critical viewpoint of the study. Clearly from your experience as an anesthesiologist you would understand that any intervention whether a drug or the use of power cranks must be tested against a control group to tease out the various interactions. Most pharmaceuticals for instance are not just tested to see if they work, they are tested to see amongst other things, whether they work better than placebo, or work better than an alternative drug. Obviously, in the case of the power cranks the study of interest would be whether power cranks works better than regular cranks. Now better can mean a variety of things, but I think for most triathletes, better would equate to increasing sustainable power, i.e. LT Power.

The abstract that you posted merely shows that exercising 8 hours a week improves various metrics of fitness. This is not ground breaking. The most that can be "proven" from reading the abstract is that exercising with Power Cranks leads to some fitness gains, whether this is more, less or the same as with regular cranks cannot be determined.[/reply]

I agree that interpretation would be difficult without a control group. To the best of my knowledge there was a control group. It just isn't stated in the abstract. I can't state that categorically as I have not seen either the protocol or the raw data but I had the same concerns when I first read it and asked the very same question question and I was told there was one. But, I can't prove it so I won't say definitely there is one. It is a shame, if there is one, the abstract does not say so for sure.

Assume there is a control group (how would you calculate statistical significance without one?) and these changes are over and above what the control group saw, would that change your view of what you are reading?

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Frank,
An original Ironman and the Inventor of PowerCranks

ditto.

this thread blows my mind.

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Where would you want to swim ?

[reply][reply]
As someone who is heavily involved in the peer review process in the field of STM (Science/Technical/Medical) publishing I have to question if the abstract being offered here HAS indeeed been peer reviewed? [/reply]

The Canadian Society of Exercise Physiology meeting is much smaller than, say, the American College of Sports Medicine annual meeting, so I'd be surprised if the abstract had to go through any sort of peer review. That said, there's no question in my mind that it would have been accepted for presentation, even, e.g., there is no mention of a control group.

Of course, even if the abstract had been peer-reviewed, you still couldn't cite it unless it were the sole source available...[/reply]


Here is another study that might be of interest to the discussion.


http://nsca.allenpress.com/nscaonline/?request=get-abstract&doi=10.1519%2F1533-4287(2003)017%3C0785:EOSTUP%3E2.0.CO%3B2

The Journal of Strength and Conditioning Research: Vol. 17, No. 4, pp. 785–791.
Effects of Short-Term Training Using Powercranks on Cardiovascular Fitness and Cycling Efficiency
Mark D. Luttrell

Department of Health, Sport and Exercise Science, University of Kansas, Lawrence, Kansas 66045
Jeffrey A. Potteiger

Department of Physical Education, Health and Sport Studies, Miami University, Oxford, Ohio 45056-3491

ABSTRACT

Powercranks use a specially designed clutch to promote independent pedal work by each leg during cycling. We examined the effects of 6 wk of training on cyclists using Powercranks (n = 6) or normal cranks (n = 6) on maximal oxygen consumption (O2max) and anaerobic threshold (AT) during a graded exercise test (GXT), and heart rate (HR), oxygen consumption (O2), respiratory exchange ratio (RER), and gross efficiency (GE) during a 1-hour submaximal ride at a constant load. Subjects trained at 70% of O2max for 1 h·d−1, 3 d·wk−1, for 6 weeks. The GXT and 1-hour submaximal ride were performed using normal cranks pretraining and posttraining. The 1-hour submaximal ride was performed at an intensity equal to approximately 69% of pretraining O2max with O2, RER, GE, and HR determined at 15-minute intervals during the ride. No differences were observed between or within groups for O2max or AT during the GXT. The Powercranks group had significantly higher GE values than the normal cranks group (23.6 ± 1.3% versus 21.3 ± 1.7%, and 23.9 ± 1.4% versus 21.0 ± 1.9% at 45 and 60 min, respectively), and significantly lower HR at 30, 45, and 60 minutes and O2 at 45 and 60 minutes during the 1-hour submaximal ride posttraining. It appears that 6 weeks of training with Powercranks induced physiological adaptations that reduced energy expenditure during a 1-hour submaximal ride.

Reference Data:Luttrell, M.D. and J.A. Potteiger. Effects of short-term training using Powercranks on cardiovascular fitness and cycling efficiency.

Key Words: cycling efficiency, energy expenditure, cardiorespiratory, submaximal exercise

frank, statistical significance can merely be comparing pre and post intervention (training) values. given no additional information, this is certainly how i would interpret the abstract. so training improves vo2 max. groundbreaking.

I think where you and others may be confused is with the term statistical significance.

Significance in the popular vernacular means one thing, i.e., having importance and relevance to, e.g., a decision.

You are conflating this idea of significance with the term statistical significance.

Statistical significance depends on the statistic that is being measured. In the case of the abstract that you posted, statistic is the difference between the VO2max and peak power between the start of the protocol and the end of the protocol.

To make it clear the statistic is not the difference between the Power Crank user and a regular crank user, that would be an intergroup difference (or difference between two groups). Rather the abstract posits an intragroup statistic (the difference within the powercrank group from the start to the end).

When a statistic is significant, it simply means that you are very sure that the statistic is reliable, i.e., the difference did not arise from chance. It doesn't mean the finding is important or that it has any decision-making utility. Nor does it in this case give any clue as to the CAUSATION of the change. Was it the Power Cranks per se? or just the fact that they were exercising in a regimented way for 8 hours a week for 6 weeks?

I think this is where a lot of people get upset with you, in that you make a logical leap to say the CAUSATION of the improvement was the Power Cranks rather than the fact that they were exercising. Now, it could turn out to be true that Power Cranks are more effective than regular cranks and may have benefits on the run. However, these hypotheses have not been verified in a scientifically CONTROLLED manner, nor has the abstracts you posted showed this to be the case.

If it turns out to be the case that there is an added benefit from using Power Cranks versus regular cranks I am sure you will soon be a lot richer and many people will buy your product, and I will be in line . Unless of course you want to give it to me for free and I'd use them without the scientific verification ;)

Frank, I don't really care what the study says, but Macca was 2nd at Kona, Tom Evans 2nd at IMLP, Courtney Ogden 2nd at IMC...all PC users. Brian Keast started winning his age group at Kona after starting to use PC's. Coincidence...perhaps. Its probably a coincidence that Fabian Cancellara and Dave Zabriskie were 1-2 at Worlds ITT on Cervelos. After all, Cervelos can't possibly make you faster...its all placebo effect :-). Like I said, these studies can say all kind of things...what I care about is how the athletes using the technology do in real racing.

If we all waited for definitive proof from studies there would be no innovation. No QR Superform, no long sleeve tri specific wetsuits, no fast clinchers, no aero helmets, and Greg Lemond would never have one the 1989 TdF using those unproven "weird" triathlon bars (aka aerobars)...someone has to take a leap of faith and try something new...hey, without that, we would not have slowtwitch and we would not have the ironman (coincidentally, Frank Day was one of the original finishers, who took that leap and decided that it might be possible to do all these three sports in those distances in one day).

Bottom line, is that there are innovators and early adopters of technology and then there are guys who will wait until something is proven definitively. Everyone can have their own approach to adopting tools and technology. I suspect that most of the guys wanting studies to prove things definitely have never worked in a startup either :-)

Dev

I'm looking forward to giving them a whirl this winter. Frank is kind enough have PowerCranks to sponsor the Timex Team, so I'm looking forward to adding them as a training tool. So I can be yet another N=1 "study." I've not heard anything negative from any of the athletes I know that use them, which is pretty impressive. At the very least, I'm hoping it'll give me something else to focus on while riding the trainer besides how boring it is! :P

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Hey Rappstar, I liked the way Dr. Tommy described it, "If you had an option to swim in a medium that ensured zero forward progress without 100% catch, would you train in anything else? This is what PC's are to cycling...a medium that ensures that you cannot pedal without setting up your stroke 100%"...and yes if nothing else, they can be quite amusing. When you get them, try this drill...ride forward with both feet in perfect synch (100% beside each other, vs 180 degrees apart). Do this at a traffic light pulling away from traffic. Then try it on the rollers and feel your abs burn!

Dev

But Dev,

The winners of those events didn't use Power Cranks. Should we then by your logic use what the cranks that the winners actually use rather than what the second place person uses?

i am all for innovation. and there is no doubt that the pc's, while not cheap, are a clever invention.

BUT,

there are two kinds of innovators.

those that let the product speak for itself.

those that do an amazing job of getting in the way of the product trying to speak for itself.

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Where would you want to swim ?

Brian Keast won his age group 2 years in a row at Kona. I'm going with what he used. And when Dr. Tommy tells me something there is usually some solid reasoning behind it :-). If there is something in common that Norman, Jasper and Victor are doing, then I'm all for it.. For the moment, I know that Macca, Dr. Tommy and Courtney had PC's in common :-). Sample size N=3. For the record Dr. Tommy has also won IMC and IMFLA, so PC's can even lead to overall wins :-)

Dev, you're drawing some interesting conclusions to say the least. Something to remind yourself is that people who introduce frequent and consistent use of PCs (or any tool) often improve simply because it brings change to their training. We all fall into some kind of monotraining rut at times which inevitably creates improvement plateaus. Once we realize it we often turn to tools like PCs to break through these plateaus. In addition, people who introduce tools like PCs are typically doing so because they're trying to bring a new level of focus or commitment to their cycling. Point being, we often don't know if it's just the change and/or new commitment level to the training program or something else (eg the tool, both, ???) that is the true cause for improvement.

Lastly, I don't think anyone is waiting for definitive proof from a study. They just have serious questions about the abstract (which is poorly written, imho) and the statements Frank is making (and rightly so).

Thanks, Chris

I think there is an inherent value to change though. And PC's present that change in a safe, functional manner. I.e., if you want something to break the plateau, you could say "I'm going to ride standing 100% of the time." This would be a change, and, assuming you rode hard, would likely force some sort of change. The value I see in PC's is that we know that they offer a training benefit (i.e. it is not clear they offer a benefit over regular cranks, at least not from the abstract of the study presented, although there was another study posted that appeared to support that conclusion) AND they are functionally specific to cycling and running. So if you currently have a good training plan, then introducing PC's is potentially a good way to take it to break a plateau. It's like I said about riding on the trainer. If PC's allow me to stave of boredom or focus 2% better, that is just as good for me as a 2% physiological benefit. Change for the sake of change can be a good thing, and PC's offer that in a convenient, functional form. Note that I say all this as a rider who has not used them, but I've seen/heard enough that I am eager to try them.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Hi Chris, you may have a point, but the bottom line is that people are making improvements on powercranks. Talk to any PC user who was dedicated enough to work through a couple of seasons on them and they all swear by them. If it is greater committment to training, then that is fine, but they realistically do force you to ride differently. The naysayers may have an issue with the abstract and Frank's claims.

Personally, I do often think that Frank's claims go too far. I'd rather that he focus on the race results of the PC users. They speak volumes. Unlike many of the posters on ST, the average triathlete won't analyse something to death. If pros get good results on them, trigeeks are the first to rush to buy the product if for nothing else than to be associated with the 'brand' that "x" pro is using. This is all Frank needs to do at this point to sell PC's. He does not even need to quantify the gains. People will buy as soon as the results come. The results have come. Frank just needs to market them and follow through with supply to meet the hockey stick effect ramp that will come.

Dev

Rappstar, To the degree that I agree with you? Well, I already decided to purchase a set a few weeks ago...

And Dev, I'm clearly not a naysayer but I do have an issue with the study and Frank's statements.

Thanks, Chris

Chris, you and me both. I'm reserving judgement on the study until we know for certain whether or not there was a control group. As for Frank's statements, I concur that some are a bit overzealous, BUT he gets drilled on the forum all the time and the product is his brainchild and passion. Would that everyone in the bike industry were so passionate. I doubt anyone here would be so perfectly objective about their own methodology. Andrew Coggan, who many here see as the strict scientist, posts his own "study" done on his wife (!) as evidence against big-gear work. That is an N=1 sample. Yet he posts links to it. If you question him, he will admit the flaws in his "study," but you notice he doesn't throw it away... Frank believes in his product, but he is not a physiologist. I don't hold his excitement or his passion against him. I wonder how many here would be perfectly objective in defending something of their own creation. That's not letting him off the hook, just thinking as a human. I'll admit my own bias in this, of course, since I've met Frank and gotten to chat with him in person as he is a sponsor of the Timex Team. But I also think I've posted on here enough that people know I'm not a mouthpiece. And again, I speak merely as someone who is excited to try the product based on feedback from training partners, not as a veteran user.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

J-

I'll be very interested to hear about yer experiences w/ the PC's, being that you are already a very strong cyclist and solid runner to begin with. Plus, you will probably be the most anal, detail oriented athlete ever to throw a leg over 'em (I mean that as a good thing ;-) so it'll be informative to see what sort of findings you come up with. Keep us posted!

Part of me has been tempted to try 'em, but the PT was a higher priority on the capital expenditure list (as was the new wetsuit). Next time I have 8 bills burning a hole in my pocket (as if!), I'll definitely give 'em another thought or three.

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float , hammer , and jog