Is that your huge hip flexors, or are you just happy to see me?

RIP, The question is how many watts are applied to the pedals to produce those 300 watts. First there are drivetrain losses. We can all agree that thoseare really small (unless you use on ofthe Wippermen chains to gain back 10 watts ;-) just joking). We have the power that is produced by the subject. Then we have the power that is transferred to the bike.

I really suggest that you reread how the power was calculated during those tests. The 1 hour test wattage was calculated from the force pedals. The index is the efficiency of the power applied verses the power output. It say everthingabout the efficiency of the sytem (rider and bike and the transfer of the power between the two).

I think I have to stop this though. I am being accused of being an engineer. You know RIP that was a low blow and almost worse than some of the name calling others have done before :-(

Oh My God..I have been on vacation and almost missed the PC thread of the year! Actually I Luv mine but in all honesty can't claim they have improved my cycling yet. However my running is soooo much better! I only use them 2-3 days a week on a trainer now for what I call run maintenance. My half marathon time has dropped from 1:55 to 1:41. Thanks Frank!! Tell RIP he needs to get laid :o)

No goobie, you misunderstand the numbers. Normally people are only applying 2 lbs or so (more or less) back pressure, which means in the example given they are normally lifting 18 lbs. (the other two lbs to get them up are coming from the other leg). So, by making them unweight the entire 20 lbs we are making them go from 18 to 20 lbs lifting work.

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Frank,
An original Ironman and the Inventor of PowerCranks

What made you select the circular pedaling style as
the one where power could be increased. If hip
flexors are the suppliers of this extra power, then
the stomping (Coggan's) style could benefit more.

I'm sorry, but that is just plain funny

I didn't select anything regarding style. I stumbled across the concept and thought it might be a good training tool for what I thought the proper pedaling style was. I think circular pedaling is the proper name to call what they do simply because one must provide some forward force around the entire circle. Whether the PC's are effective at teaching any particular style is not important in my book. In fact, I don't know what style we actually teach because I have never seen pressure plate pedal force analysis done on well-adapted PC'ers. So, the question is, rather: Is what they do to teach a new style and train new muscles (or, better train the old) an improvement over what people did before? I would say it is.

Where the extra power comes from is probably several different sources, the big ones being simply unweighting the recovery portion and, at the same time, redirecting pedal forces to be more tangential (see too slows questions to Winkle above). I think it is the combination of several small improvements, all added together, that result in the large power gains, not one big thing.

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Frank,
An original Ironman and the Inventor of PowerCranks

"Where the extra power comes from is probably several different sources, the big ones being simply unweighting the recovery portion and, at the same time, redirecting pedal forces to be more tangential (see too slows questions to Winkle above). "

How does unweighting the recovery pedal increase power? And how much power would this be worth (approx.)? What is the percentage gain, in wattage, of this increased benefit that PCs offer for the unweighting?

I personally think that good and powerful pedalling really is all about pushing down really hard on the pedals, but hey, that is based on the whole "caveman walk up hill" theory.

Such a result would be too bizarre for words, unless, perhaps the subject was someone like Skyman, or you (who has no trouble single legged pedaling 25 miles or so).

I think I will wait until I see the actual data. Why don't you see if you can get it and the circumstances (the PC history of the athlete).

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Frank,
An original Ironman and the Inventor of PowerCranks

Why? Afraid I might break your crank?? Actually can't imagine a more stimulating night then listening to you describe "angular velocity and how crank length defines the power applied". On second thought, I think I will go watch Shrek2 instead...Ciao

Rip, the only additional work PC's require of the HF's over stair climbing is lifting the weight of the pedals, crank, and shoe. Since, many when they stair climb wear heavy shoes like work boots, this difference is nil. The only other thing PC's do is require a higher lift, but nothing out of the ordinary.

What on earth does the fact that the extensors are stronger have to do with this. The extensors are stronger and do more work in both instances. Wasn't it you who referred to the unnatural use of the HF's, and climbing stairs upside down using inversion boots? Where on earth did that come from? What is unnatural about what the PC's make the user do.

Gee whiz, if you have no trouble single legging it for 25 miles it seems to me that you should have no trouble climbing stairs upside down in inversion boots because you can already do what the PC's train ordinary mortals to do. Why do you object to them again?

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Frank,
An original Ironman and the Inventor of PowerCranks

As an always interested and inquisitive observer, I'm trying to decide if this was no to "Is that an offer" or if it was no to "does it come with a 90 day money back guarantee".

So 25 miles one-legged was hard. Glad to hear that. Only one word to help you understand what the PC's do for the athlete. In some ways, they are easier than one-legged drills because you don't have to drive the bike on the back side, only lift the foot up to keep up with the down ward crank but, in other ways they are a lot harder than one legged drills because, when PC'ers start to feel their HF's turn to toast, what do they do to survive? One-legged drills. Allows resting of one leg while the other keeps the bike going.

So, to summarize. To a regular crank trained rider, one-legged drills is one of the toughest things they do. To a PowerCranker, it is one of the easiest.

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Frank,
An original Ironman and the Inventor of PowerCranks

 
How does unweighting the recovery pedal increase power? And how much power would this be worth (approx.)? What is the percentage gain, in wattage, of this increased benefit that PCs offer for the unweighting?


Sitting on the saddle of a bike whose chain has been removed from the chainwheel, with your feet on the pedals set in 3 - 9 o'clock position, you will
find perfect balance. Lift the rear foot off the 9 o'clock pedal and see what happens and that is
without making a conscious effort to apply power to
the pedal. You don't need PC's to gain this free
additional power advantage, any sensible rider can
do it naturally.

JC wrote: "If your extensors are starting to fatigue you should recruit your flexors more. If your flexors are fried, you should rest them and use your extensors to a greater extent."


Sorry if I thought you meant that as a stand-alone statement. I thought we were in agreement about this statement as it stood. I apologize for assuming so.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

RVP wrote: Because at submaximal intensities only a fraction of all possible motor units within the leg extensors are being used, leaving many motor units still available to either 1) carry on the task when the initially recruited motor units fatigue, or 2) be recruited to increase the exercise intensity up to 100% of VO2max.

You still evade answering my question.

At submaximal intensities, the extensor group (with only a fraction of all possible motor units being used) will still fatigue enough to decrease their work rate. Whether other motor units are available or not is immaterial...we see a decrease in work rate of the extensors after a certain time.

We cannot afford to increase their workload closer to 100% of VO2 max, because we still have to run when we get off the bike...which is going to require those extensors to work for another long period of time. So, now what? Why not use flexors to help the extensors by either decreasing their workload so we can perhaps run faster when the bike leg is over, or using the flexors to increase speed some? Again, he cannot just work the extensors harder, or it hurts performance by slowing him down before the bike leg is finished and/or slowing the run after the bike.

Do you understand the question, or are you just avoiding giving a straight answer?

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Perfection wrote: "How does unweighting the recovery pedal increase power? And how much power would this be worth (approx.)? What is the percentage gain, in wattage, of this increased benefit that PCs offer for the unweighting?

Sitting on the saddle of a bike whose chain has been removed from the chainwheel, with your feet on the pedals set in 3 - 9 o'clock position, you will find perfect balance. Lift the rear foot off the 9 o'clock pedal and see what happens and that is without making a conscious effort to apply power to the pedal. You don't need PC's to gain this free additional power advantage, any sensible rider can do it naturally. "

What you describe is exactly the case. unweight that back pedal and you get all this "free" power just by lifting your leg a bit. And you are right, it is very natural. In fact, ifyou do not do that some, you cannot make the pedals go around. The problem comes from the fact that it is not natural to completley unweight the pedal because we learned to ride a bike not attached to the pedals so we learned to backweight a little to keep contact. So, we unweight a lot but not completely so there is a little bit of back pressure. If we can just learn to unweight a little more, we can get a little more free power. That is part of what PC's do. They force the user to unweight completely and in the process retrain the brain to make it "natural".

So, how much is that worth? Depends upon how "bad" the athlete is now in this particular regard and how "good" he is in producing power. Using the back pressure data in Whitt and Wilson I believe eliminating this negative alone can account for a 10-20% increase in power in most users, less in elites, more in beginners.

Frank

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Frank,
An original Ironman and the Inventor of PowerCranks

RVP wrote: You used stair-climbing of an example of why use of the hip flexors must be considered natural. I say that that is a poor analogy, or at least an incomplete one, because it ignores the much larger forces being generated by the leg extensors in this scenario. Regardless of how additional force/power you claim can be generated using the hip flexors after a person has trained with PCs, it is still necessary to compare it that generated by the leg extensors to keep things in context.

You are correct....Stair climbing and pedalling are not the same thing. Pedalling is easier, because you don't have to have hip flexors at all to pedal with a normal crank, but, you must have hip flexors to climb a staircase like "normal".

Ever run stairs? Ever trip going up a stair because you didn't lift you foot high enough? I have, and I have. I find it much easier to run stairs since training my hip flexors to get my foot up higher. Certainly, the great majority of the work being done is firing extensors to propel me up the stairs...but, no way could I go two, three, or four at a time without good hip flexor action. Pedalling is different than stair climbing, because when stair climbing, you don't use your extensors to assist your flexors to pick the foot up high enough to clear the next stair.

I don't know if you've read Skyman's report of finding PowerCranks fairly easy, but, he says he has done a LOT of uphill running...which can require more hip flexor action than flat terrain running...maybe that is why he isn't having a hard time adjusting to PowerCranks.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Yaqui, what surprises me about Skyman is the HF endurance he has seemingly gained running hills. As opposed to XC skiing, the problem with hills or running stairs is the hill usually comes to an end in only a couple of minutes then the athlete must turn around and run down, which requires very little HF action. This is not a very good way to gain endurance event endurance, but Skyman seems to have done it, at least to a certain extent. Shows it is not impossible.

Frank

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Frank,
An original Ironman and the Inventor of PowerCranks

Yes, I would think XC skiiers would have the easiest time adapting to PowerCranks. I also have heard XC skiiers say PC's really helped their skiing.

What WOULD surprise me, is if Skyman uses them for a few months and reports no significant change in his running times. Sure, it's possible he won't. I think he'll be pleasantly surprised, though.

I just did my favorite workout with PC's today. Warm up on them, run two miles, get back on the bike for a couple of miles, run a couple, etc. I got 8 miles running and 10 on the trainer today, first day I could do anything hard in a couple of weeks. I think I coughed out the last bit of bronchitis/pneumonia crud I've been fighting, and I'm relieved that I'll be able to race this weekend after all. I may not have my best times, but it sure is nice to feel good for a change. I'll go out on a limb and say I might even have my fastest run split of the year this weekend, if I recover well...I'll know that tomorrow morning. This particular PC/run brick is usually closely predictive of my performance in the following weekend's race. Who knows how the swim will go...missing two weeks of swimming can't be good for this non-fish.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)