Effects of Short-Term Training Using Powercranks on Cardiovascular Fitness and Cycling Efficiency
Powercranks use a specially designed clutch to promote independent pedal work by each leg during cycling in the downward and upward phases. This study examined the effects of 6 weeks of training using Powercranks or normal cranks on maximal oxygen consumption (VO2 max) and anaerobic threshold (AT) during a graded exercise test, and heart rate, oxygen consumption, respiratory exchange ratio, and gross efficiency during a submaximal 1-hour ride. The subjects trained for an hour a day, 3 days a week for 6 weeks. No differences were observed between or within groups for VO2 max or AT. However the Powercranks group had significantly higher gross efficiency, lower heart rate and VO2 at various times during the 1 hour ride post-training.
Powercranks training appears to result in a decrease in energy expenditure and enhance physiological adaptations at a given workload, which may ultimately enable cyclists to increase speed more readily during competition and thereby improve performance.
Luttrell, M, Potteiger, J. (2003). Effects of Short-Term Training Using Powercranks on Cardiovascular Fitness and Cycling Efficiency. Journal of Strength and Conditioning Research, 17 (4), 785 – 791. (1/28/2004)
There are myriad ways in which one could interpret data as presented in this study. Given that statistical values generated from utilizing a scientific methodology aren’t always presented in the most factual, non-misleading manner, one could easily say that this particular study is no better than another study which statistically “proves” the opposite findings. Wait, you say, there is NO OTHER scientific study that refutes these findings? Harrummph! Well, then, the only logical conclusion at the moment is: NYAH, NYAH, NYAH…told you so!
Actually, Jason, this study has been discussed a little on this forum already. You probably missed it because the topic doesn’t attract the vehement nay-sayers attacking the proponents of PC’s like in the “old days”. For those of us that have been training on PC’s, it’s really old news…we really don’t require scientific studies to tell us what our Heart-rate monitors and Timex watches were showing us about the effectiveness of PC training.
Here’s the ultimate marketing for PC’s which some regard as an overpriced ~$700 gadget that will eventually go the way of EXO-Powercam, biopace chainrings and other “innovations”. Out of all PC purchasers, what percentage return their cranks after the “free” 60 day trial period. I suspect it is probably not much more than 1%. Frank Day, perhaps you can comment. Those statistics alone should speak for the value that customers feel they are getting from the toy. Personally, I believe there are performance gains so I have kept mine. Anyone return their’s ?
As for the study, we can all make data tell any story we want, but as in any business, aside from generating profits and shareholder wealth, the real guage is your level of customer satisfaction (take care of the customer and the company will take care of itself…right ???)
in a way, you have to admire a dude like mr willet. guys that are doggedly and utterly convinced they know what they are talking about when in fact . . .they don’t. perseverence, so they say, is a virtue and mr willet is the mother theresa of persisting in thinking he knows about that which he has no experience with, so there is that.
i myself must take my hat off to him. as a creative and prolific PC basher i only lasted around 3 months or so until i broke down and put my legs where my mouth was and gave them an actual road test, with commitment, no less. this was, obviously, weak of me. i should have kept on blasting them without knowledge of them - and i would have even had a head start on kraig! dang.
Kraig, at the age of 37 I did my tenth Tupper Lake Half Ironman in 2003. For 10 years, I tried all kinds of training approaches. Up till then, my best bike split was 2:27 and best run was 1:25. I biked 2:23 this year for 90K and ran 1:24. Training volumes and intensities were similar to all years past, and I did my standard pre race taper, so for the life of me, after 18 years of doing triathlon and doing the same race 10 times, I have no clue how I could have made such a large improvement (5 min combined bike-run) without PC’s.
Now can you tell us about these Redshoe things or is it a bogus non existent hoax ?
ahhhhh. well i will stand corrected, sir. i would not have gathered that from your posts, i must have missed it along with the razor bit. sincere apologies all around.
as for the razor - all that about the simplest explanation and all. . . . . . have you triied installing them on a bike and busting a$$ pedalling as far and fast as you can for a few months yet? a simple plan for a complicated man. just an idea.
“Out of all PC purchasers, what percentage return their cranks after the “free” 60 day trial period. I suspect it is probably not much more than 1%. Frank Day, perhaps you can comment.”
It is about 0.5% or 5 out of a thousand. Some of those have been returned because the user didn’t get their bike when they expected and never mounted them.
“Out of all PC purchasers, what percentage return their cranks after the “free” 60 day trial period. I suspect it is probably not much more than 1%. Frank Day, perhaps you can comment.”
It is about 0.5% or 5 out of a thousand. Some of those have been returned because the user didn’t get their bike when they expected and never mounted them.
Frank, you need to post that statistic on your website by the 60 day free trial ! 0.5% return rate is pretty good. I do agree that there may be more dissatisfied custmers who never bother, but you should leverage that number for marketing purposes. It is likely more powerful and certainly more credible than any claims with respect to gains in max or sustained power.
I agree with Little Bo Peep…I mean Mr. Van Winkle in that a 5 minute overall improvement is not that overwhelming. I have been on the PCs for 3 months and have seen a dramatic improvement in my 10K, 10 mile, and half marathon times. I won’t be testing my bike improvement for another month or so as I am still working to get my cadence up. In any case, the run as always been a limiter of mine (at least at the IM distance) and PCs seem to be having a positive impact.
Dear Mr Rip Van Winkle (or whatever you really are), I believe beating your PB on a given course by 4 min is pretty significant. Hey, as long as I believe they work, who cares. In 9 previous tries on that course, I was always between 2:27 and 2:31 and most of the time in the 2:29 to 2:31 range. Blowing away a bike course PB after that many years by 4 min and going 2:23 and still running a tad faster than my run course PB is something I will take any day.
Again, who cares about performance when only 0.5% of customers return the product after the 60 day trial. Some folks must think they are good :-).
All the best in your training and racing whatever approach you use. Since you dropped in on this thread, clearly you care about PC’s otherwise you would ignore this entire bogus thread.
Rip wrote: You’re right: except for Kraig, we’ve all given up, just like most people have given up on trying to convince members of crazy cults (like Christianity) that there is no god.
Maybe this is a little like when Copernicus tried to convince people the world was round. Than guy was a NUT, wasn’t he? As far as Kraig’s interest goes…he’s genuinely a very good source of scientific theory exploration. His interest can get too technical for some people, but, his attempts at science are very good.
However, I have a question for Kraig: How did the world get round, and just how round is it? The answer, or top probable answers, are discernable to a degree, but, it doesn’t really matter that much when compared to the fact that the sun appears in the east each morning and disappears over the western horizon each evening. One could easily discuss how the sun doesn’t really “appear” and “disappear”, nor is it exactly happening due east or due west unless certain other conditions are met, such as being at the equator of the earth when viewing the sight, and it’s still only an accurate statement twice a year. See what I mean?
A reasonable person could acertain, from personal experience, that the sun appears in the east in the morning and disappears in the west each evening. Even if this person has no idea that the earth is round, is rotating on a tilting axis, the sun is 93million miles away, etc. Personal experience would still suffice to show the reasonable person that the statement is true.
Same goes for PC training. Get on them. Experience what they do. Whether or not you can dissect all the reasons why they work isn’t as important as the experience gained and results observed.
Same goes for PC training. Get on them.
Experience what they do. Whether or not you can
dissect all the reasons why they work isn’t as
important as the experience gained and results
observed.
I’m sorry Yaqui, I don’t quite buy that argument. I’m not saying the PC’s don’t work - it seems like they do - but anecdotal evidence will never be a substitute for methodical scientific analysis. All the individual testamonials of how people improve after switcing to PC’s are potentially fraught with “Redshoes”-type biases. That’s why it’s nice to see actual controlled studies done.
Personally, I’m glad people like Kraig are interested in how these things work.
anecdotal evidence will never be a substitute for methodical scientific analysis.
I 100% agree.
All I was saying is that actually understanding HOW and WHY something works can be more difficult, and difficult to a point of unimportant, compared to finding out IF they work. It’s much easier to show they do or do not work, using the scientific method, than to actually know how and why.
I’m one of the people that like to know the how and why, too. I also like to know that the darn things work before I’m stuck with the bill. But, in the meantime, I trained on them and saw dramatic results. Maybe not as dramatic as some, maybe more dramatic than others, maybe just plain old average. They work for me. I have lots of ideas why they work for me. There may be different reasons they work better for different people. But, like aspirin relieves headaches and body aches for most people, whether or not I understand how and why, I took two Powercranks and became faster at running and biking.
Understand I’m not saying aspirin works the same for everybody, and there are some people that can tell you how and why aspirin works, the important thing to me is, if the aspirin didn’t work for me, I could get my money back.
devashish paul - Unless you are a mechanical rather than biological machine the fact that there is very little variation in your results is itself abnormal. I think it reflects a psychological limiter rather than a physical one, i.e. you hadn’t gone faster because you didn’t think you could (and the PC’s altered that belief). You might be better off with the belief that consistent training will produce improved rather than consistent results. A great race stands out because it is inconsistent with prior results. Maybe if you gave yourself permission to suck sometimes you could let yourself be great too.
Rip wrote: Nice analogy about Copernicus, but for one thing: you’ve got it all backwards. The “reasonable people” of his time thought that the earth was flat, and Copernicus was unable to convince these religous devotees otherwise using science (and was killed for trying). Hopefully the same won’t happen to Kraig.
Kraig’s in no danger, thankfully! It’s not a backward analogy in this respect…some new idea came along, and the old school people refused to give it credence. It doesn’t matter how much “proof” one has or doesn’t have, it doesn’t matter how much scientific method one has or doesn’t have, nor how many peer-reviewed studies there are, NONE of these makes the earth flat or round. It is what it is. Perception is reality. If I spent $1000.00 for a coach and went from years of obscurity to 5th in the state, people would say, “It was the coaching that did it.” Maybe it was just that a coach motivated me more, or corrected a flaw in my pedal stroke or running stride.
Well, I did go from years of obscurity to 5th in the state, and I spent well under 1000.00 for a type of coach…a coach that forced me to pedal more “roundly”. This coach didn’t care how bad a day I had, if I was really tired, if there was a headwind, if it was hot or cold, etc. EVERY PEDAL STROKE, that stupid mutha forced me to do it better than I used to do it. It worked for me, it showed up in my results. I don’t really know all the reasons it did work, just that it got the results I wanted. IF it is for reasons similar to the Redshoe reasons, so be it.
Studies like the one in JSCR suggest it may be more than the Redshoe experiment.
jhc wrote: Now if I could improve even to 5th in my neighborhood, it would be quite an achievement.
Just remember, you are “that guy” to lots of the people in your neighborhood. You know, “that guy” that is a triathlete, “that guy” that they wish they could somehow have the guts to imitate. In the end, it doesn’t really matter what place any of us achieve, but it sure is fun seeing how much we can improve while we’re here!
Uh, I think Copernicus was involved in bringing about a heliocentric view of the solar system, rather than the prevailing geocentric view. By that time, everyone knew the world was round (how else to explain a ship sinking below the horizon?).
And Copernicus was no nut. The “scientists” who attempted to model the Church-mandated heliocentric view were coming up with more and more elaborate mechanisms to explain things like the retrograde motion of Mars and other planets (at times, it appears to move backwards across the sky over the course of days). Look up “epicycles”.
“Reasonable” people of the time, at least those with a scientific education, could ascertain from personal experience of watching retrograde motion that the Church position just didn’t make sense.
I think that works out at about $150 a minute ! I think our times are pretty close. Send me a check each year for $100 and I’ll let you beat me.
So you spend $800 on an idea like this and lo and behold!, it turns out to be demonstrably good. You improve and soon more studies are done and they prove, at long last, beyond a shadow of doubt, that the PCs give you an extra 5/10 minutes. Shortly after that so many Tri geek bozos demand the product that some entrepreneur buys 20 and opens a PC club. 500 Tri geek bozos join and within a year everyone who has any sense is training with PCs.
For a short period of time you improved relative to your geek competitors, now you’re back where you were.
Except of course that now you’re $800 poorer and Frank’s $800 richer.
