Poor man's Powercranks? (PPC)

Fday

In the early days we were stuck with anecdotal reports, our own small in-house study, and theoretical benefits to support our claims. All we got was, Where are the studies? Now that there are starting to be studies we are told the same thing, two studies aren't enough, or they are flawed, or they don't comport with my bias, or something else. They are what they are.

We can only put forth the science (studies) as they appear. When other studies become available we will surely let everyone know.

Frank

Fday

No I don't. It would be unusual that such a result would come from an increased trainng load as most riders see reduced volume when they take up PC's, at least for the first 4-8 weeks or so. I understand the group contained one or two professional cyclists and a bunch of fairly elite amateur cyclists and triathletes but I don't know the specifics of the study as we don't run them.

Frank

n crowley

From the day a rider starts to use PC's, for how long is the hip flexor/thigh pain expected to continue ?

Fday

It depends upon how much effort one makes to adapt and from what point they are starting from. For most it is pretty much gone anywhere from 4-6 weeks, although it will continue as long as one is continually bumping up the mileage beyond what the muscles take reasonably easily.

ric_stern/RST

where's the control group?

__________________
http://www.cyclecoach.com

Fday

If there was one they are probably in Canada. :-)

We don't know that there was one but I have been told that there are other valid ways of doing a study that can give statiscally significant results without needing a control group. This study was done by a very reputable group out of Canada so one would assume they knew what they were doing but without access to the protocol and data one cannot know for sure.

Frank

ric_stern/RST

Calling Robert Chung... he's our stats man. I can't possibly see how you can have an intervention such as Power Cranks and not have at least one control group. It seems, at first glance, that the methodology is wrong.

And Frank, your spelling is worse than mine.

Ric

__________________
http://www.cyclecoach.com

Fday

Early on I had presumed that there was a control group as I, also, couldn't figure out how one could calculate statistical significance without one. But, I have been told there are many ways a study can be designed that doesn't require one or, perhaps the group acted as their own controls. The fact that this well respected group calculated statistical significance suggests they had designed their study in such a way that they could. Unfortunately, they didn't tell us in the abstract how they did that.

ric_stern/RST

you misunderstand, or perhaps are doing it on purpose.

It isn't the statistical significance i'm worried about per se, it's the fact that the methodology appears incorrect. That is, the point made by Rmur. Perhaps, prior to intervention the group were all doing an hour a week in 39 x 17, while eating chocolate bars, drinking beer and not in the slightest bit interested in their training. They then, did 8 hrs/week for 6 weeks and gained an improvement. well, uhm, what would you expect?

Likewise, i'm expecting a 50% increase in sustainable power from the beginning of the year to sometime by the end of april. Whether i disclose that i had 4 weeks off my bike and ended up horribly detrained you're saying wouldn't matter... I'll have had a significant increase in power...

Ric

__________________
http://www.cyclecoach.com

Fday

It is not possible to know if the methadology is incorrect without knowing what the methodology is. If they chose the correct test for their methodology then it is relevant if the results were statistically significant. If there are many ways to do something then it is not necessarily deficient if it is an acceptable way but not the way you would have chosen.

Why would you would think this group would choose to do a study in which they took riders and put them on enforced bedrest and fed them chocolate for 6 weeks then started PC training? I guess it is possible if someone wanted to make the cranks look good but it has been my experience that most researchers don't believe our claims so they make their protocol as rigourous as possible to try to minimize the PC benefit. The cranks look pretty good despite this.

So, your presumption is one I don't think is fair to make even though I also would be much happier if we had all the data. I accept the fact that without the protocol and the raw data to check one cannot "know" how good the study was. But, the authors put their name to this study. If they did crap work it will come out. I understand these authors have an excellent reputation such that I doubt they would put their name to it and present it at a national meeting if they knew it was crap work. So, for you to assume it was a piece of crap just because you don't like the results is a little to much for me.

Anyhow, take your beef up with the authors. I can only present the data I have.

BTW, I wouldn't call someone, who has an excellent base like yourself, who takes 4 weeks off their bike, "horribly detrained". A better term might be fully rested and reinvigorated.

ric_stern/RST

think about it like this: if you wanted to trial an ergogenic aid intervention (e.g. caffeine), you'd need to use a randomised, placebo, double-blind crossover methodology, to see how it worked and whether there was a learned effect (e.g. if you always did the caffiene trial last, you could attribute the increase in performance - if there was one - to a training effect). Now, while you can't do a double-blind crossover study with Power Cranks, there are other ways to make the testing more rigorous, because without a control group, the study is a joke.

For e.g., you could have a contol group doing the same training after initially matching the control group with the test group to make sure that both groups were as fit as each other and doing the same training. then one group would do the new training with power cranks, and the other group would do the exact same training without the power cranks.

Here would be a much better example of a training study, with a control group http://www.ncbi.nlm.nih.gov/entrez/...t_uids=12439086




Detraining occurs rapidly, such that my FTP has dropped significantly by ~ 100 W and my map by ~ 70 W. It may also be that performance decline isn't helped by my 'disability' (although i have only anecdotal data on that score).

http://www.ncbi.nlm.nih.gov/entrez/...l=pubmed_docsum

http://www.ncbi.nlm.nih.gov/entrez/...l=pubmed_docsum

Ric

__________________
http://www.cyclecoach.com

acoggan

No, Frank misunderstands. That is, despite (or perhaps because of?) his background it is clear from his comments that he has, at best, a very rudimentary grasp of experimental design and statistics. It is therefore a waste of time to discuss such issues with him, because he quite simply doesn't "get it".

acoggan

If you're not willing or able to discuss the strengths and limitations of this (or any other) study involving your product, you shouldn't try to use them to support your claims.

acoggan

Dr. Stephen Cheung would be the most senior individual. A search of PubMed reveals that he has published one to two papers per year for the past ~15 y, almost entirely in the area of thermoregulation. Analysis of his publication record using the ISI Web of Knowledge indicates that these papers have been cited a sum total of 236 times, or an average of 9.08 times each, with his 'h index' being 8. So, while I don't know him and can't comment on the quality of his work (which AFAIK is excellent), it would appear that it has yet to have a significant impact even in his sub-speciality. I'd therefore say that it is yet another 'Dayism' to claim that he/his coauthors have quite the reputation that you repeatedly cite.