Leg power discrepency



Fday said:
It makes sense to me that part time (or short duration) encouragement would be less than 100% effective and that people would sooner or later revert right back to where they were without continued reinforcement. That is in agreement with the studies and observations you mention.
Ok, so two follow up questions for you:

The people that I personally know have used power cranks don't use them 100% of the time, of course, and it seems like you accept that. Given that is the case, we can assume that at some point a rider will use conventional cranks for some riding.

So let's assume that the rider does change over to conventional cranks for some period of time. Do you have any data from the period of time immediately after the changeover (presumably while the rider is still "under the influence" of power cranks), when presumably, their pedalling is close(r) to a perfect 50/50 balance, that says that the rider will put out more power on conventional cranks? Hopefully this data would be from a "downstream" power meter, i.e., not an ergomo.

Also, assuming the now continue to ride with conventional cranks, do you have any data that shows a power drop off with continued use of conventional cranks (when their balance presumably degenerates)?
 
Steve_B said:
Ok, so two follow up questions for you:

The people that I personally know have used power cranks don't use them 100% of the time, of course, and it seems like you accept that. Given that is the case, we can assume that at some point a rider will use conventional cranks for some riding.

So let's assume that the rider does change over to conventional cranks for some period of time. Do you have any data from the period of time immediately after the changeover (presumably while the rider is still "under the influence" of power cranks), when presumably, their pedalling is close(r) to a perfect 50/50 balance, that says that the rider will put out more power on conventional cranks? Hopefully this data would be from a "downstream" power meter, i.e., not an ergomo.

Also, assuming the now continue to ride with conventional cranks, do you have any data that shows a power drop off with continued use of conventional cranks (when their balance presumably degenerates)?
How our customers use the product is all over the map despite our best efforts to use them as we feel is optimum. Regardless of what we feel is best I accept that most of our customers use them in a manner they feel will be optimum for them. They pay their money, they can use them as the want. My impression is that most of our customers use regular cranks at least some of the time regularly, . Many go exclusive during the off season then part time during the season. Others are part-time from the get go. Only a hand full a exclusive use all the time, including racing.

Now, regarding data, I have none other than the anecdotal data I get from grilling customers who I happen to talk to about their experiences. My expectation is that it is sort of like training in general. The more base you have the slower you lose your ability if you stop training. I think the same is true of the PC pedaling pattern. So, if you have 6 weeks on them and then do an Ironman 112 bike race you can expect to be pretty much back to your earlier pedaling style by mile 25. If you have 2 years and 20,000 miles on them you can expect your pedaling style will remain good for the entire race.

One thing is clear, people who used them quite a bit, stopped during the season, and then get back on them the next off season, do not start from the same "zero" level they were at when they first started them. So, it is clear, while they have lost something, they have not even come close to losing everything. That suggests to me that they continue to pedal the pattern and use the muscles more than they did before PC's but less than the PC's force them to do, so they lose something but not everything.

So, the only data I have is anecdotal (plus the Italian study which doesn't tell us much because it was so short) but it is better than nothing. Does that answer your question?
 
Fday said:
Does that answer your question?
Yes.

I assume that you understand why I would want to see such a thing; it would go a long way toward showing the positive effects. Ultimately, I want something to either give me more power, increase my speed or reduce my PE (or all the above). Without quantifiable results, it can be a tough sell.
 
Steve_B said:
Hopefully this data would be from a "downstream" power meter, i.e., not an ergomo.

Also, assuming the now continue to ride with conventional cranks, do you have any data that shows a power drop off with continued use of conventional cranks (when their balance presumably degenerates)?
What's a "downstream" powermeter - are these like the big water wheels that used to power the mills back in merry old England? ;)

Would your description of "downstream" rule out the SRM units?

If a power measuring device provides repeatable results why the hatred?

I know that after using the Powercranks since November, but despite weighing more than I did last summer, I'm faster up the hill I use for testing. I have the Powercranks with the "lockout mode" and decided to lock them out on two rides up the hill to (a) let me see what it feel like to 'have it easy' again and (b) ride out of the darned saddle for a while longer.

I do have a question for Frank though. Is it a physical impossibility to ride out of the saddle when on a trainer? The "family jewels" would appreciate me standing up every once in a while. :)
 
acoggan said:
Prior to the 1984 Olympics, the US team pursuit squad trained extensively with EMG biofeedback to encourage extensive "pulling up", but reverted to their prior pattern of muscle activation when they stopped training this way. Much more recently, both Jeff Broker and Max Testa have anecdotally reported that they've seen PowerCrankers revert to their prior way of pedaling once they stopped using the cranks (as much). Finally, on another forum someone (Frank himself?) linked to a PowerPoint presentation from an Italian (?) researcher who reported the same thing, i.e., that continual reinforcement is necessary.
Isn't part of training the aspect of continual positive reinforcement and forcing the body to work in a way that you believe it to be most beneficial for the results that you intend? I thought that was basic training 101... If you stop doing something that taxes you in a particular way the why would you think that you'd keep the improvements over a long period of time?
 
Fday said:
At least, now we can explain your imbalance. Injury indeed. :)

One question, what kind of problems were you having with your hip before PC's (I assume pain was one, was there more) and how long did it take for them to resolve after starting training with them? Now, it is just a matter of continuing the rehab to complete balance.

Also, congratulations on your PC mileage. Those 1000 kms on regular cranks though is slowing the balancing process down somewhat I suspect. You should eventually make it but it is going to go a little bit slower than if you were exclusive PC's. Not sure if your season will allow this but I would try to go all PC's until you are fully balanced and then try to re-integrate regular cranks back into the training fold to keep you "race ready on regular cranks".
I fell off the bike in 2003 had a classic surgery for a broken neck of femur. One year later a necrosis of the femoral head was diagnosed. Total hip prothesis.
In fact my suffering from my hip prothesis was never on the bike. It was when I'd stay seated for a while (let say 15' or 20' or more) and I'd stand up then it 'd be painful to start walking again. Pain would last for a few seconds then the painful sensation would disappear while walking.
After doing a few weeks of PC's training I realized that that particular painful sensation when standing up had diseappeared.:)
 
Fday said:
One thing is clear, people who used them quite a bit, stopped during the season, and then get back on them the next off season, do not start from the same "zero" level they were at when they first started them. So, it is clear, while they have lost something, they have not even come close to losing everything. That suggests to me that they continue to pedal the pattern and use the muscles more than they did before PC's but less than the PC's force them to do, so they lose something but not everything.

So, the only data I have is anecdotal (plus the Italian study which doesn't tell us much because it was so short) but it is better than nothing. Does that answer your question?
I had the opportunity of sharing some time with one of the Credit Agricole Pro Tour teamate Remy Pauriol who's been riding on PC's (training) for 2 years now.
He told me that beside the regular winter training on PC's (and regular cranks) he was doing some PCranking during the racing season, mainly to help his recovering in between races and also to do some kind of "recalling" (in french we'd say piqure de rappel) for his pedaling technique which according to him is the most important interest in the PC's.
 
swampy1970 said:
If a power measuring device provides repeatable results why the hatred?
Ergomos are proven to be less accurate than SRMs and Power Taps. I would not want its problems mucking up the data.

Unfortunately when you show something other than simple blind acceptance and ask someone something more pointed and specific than a "softball" question, it's regarded by some as "hatred" for some reason that escapes my understanding. It's called technical inquiry. You don't have to hate in order want real answers.

swampy1970 said:
I know that after using the Powercranks since November, but despite weighing more than I did last summer, I'm faster up the hill I use for testing.
How can you be sure that it is due to the PC's and not any other training intervention?
 
veloventoux said:
I fell off the bike in 2003 had a classic surgery for a broken neck of femur. One year later a necrosis of the femoral head was diagnosed. Total hip prothesis.
In fact my suffering from my hip prothesis was never on the bike. It was when I'd stay seated for a while (let say 15' or 20' or more) and I'd stand up then it 'd be painful to start walking again. Pain would last for a few seconds then the painful sensation would disappear while walking.
After doing a few weeks of PC's training I realized that that particular painful sensation when standing up had diseappeared.:)
Wow!!! I will have to put on my thinking cap as to what we might have done to help with the sitting to standing problem you had. I can only think that it must be related to the muscle balancing. At least most people will not say this is related to placebo effect as I can't think of anyone who might have anticipated such a change from using these.

And, thanks for the PM giving me more details. I am always trying to learn as much as I can about what these may or may not do and the specifics of peoples experiences so I can tell others should they have a similar problem.
 
Steve_B said:
I was asking a question, not making a statement.

I was hoping that you, as the inventor, would have some data on how permanent the changes are.
I apologize for the misunderstanding, I missed the question mark.

Anyhow, I have no data, at least as regards left / right imbalances and whether they would recur after stopping use of the PowerCranks. It is just my expectation they would not. Fore/aft imbalances and pedaling coordination issues is another story and I think there is good data there to suggest these will revert, albeit slowly, depending upon the base.
 
Steve_B said:
Ergomos are proven to be less accurate than SRMs and Power Taps. I would not want its problems mucking up the data.

Unfortunately when you show something other than simple blind acceptance and ask someone something more pointed and specific than a "softball" question, it's regarded by some as "hatred" for some reason that escapes my understanding. It's called technical inquiry. You don't have to hate in order want real answers.

How can you be sure that it is due to the PC's and not any other training intervention?
First one. Do the Ergomo's read a different value than comparable units (SRM, PowerTap) consistantly or does the reading 'drift' somewhat under a proven steady power - ie, if I were to hook up a 1/2 hp electric motor to the bottom bracket of an ergomo device would I see a constant ~373watts or a constant 350watts or a range that fluctuates between say 360watts and 386watts for that given measured load? Just curious as I'm going to be in the market for a non-SRM power measuring device - unless Frank wants to swap my PowerCranks for one of the new SRM equiped PowerCranks for a nonimal upgrade fee ;)

(that's the only way the set of Powercranks that's currently on my bike will be removed.)

Secondly. I've kept the training pretty constant over the last year with the exception of two things. One, I had a lengthy period of time off the bike in October and early November - during this time off, all of which was on strong pain meds I put on the extra weight. When I got back on the bike I noticed on regular cranks that I was obviously slower on the trainer. Two, I changed from regular cranks to powercranks towards the end of November. The training load was somewhat reduced during the initial adaptation period and instead of being a 30 minutes on, 5 off, 25 on, 5 off, 25 on..... it was similar time periods that were fragmented, eg 30 minutes on but split into 10 sub intervals where a rest was required due to the inability to pedal any more and initially I was limited to the initial 30 minute session. Over time these "sub intervals" were reduced in number until the desired 30 minutes, 25 and 25 were achieveable. My training is done on the trainer this time of year as I only have late evenings in which to train which is why I don't get a nice 3 hour ride in....

I have to say that my pedaling has changed. I no longer have to think about pulling up - it happens because it has too and yes it still hurts but I now think more about pushing down earlier and harder. Maybe it's due to the lack of thought required but it does actually feel more natural. It's been noted that cadence is a problem when getting used to the Powercranks, but I'm hovering around the 80rpm range most of the time now and that's rising by an a couple of rpm per week at the moment.

As stated in a post in another thread, I'm not sure why I was faster on the hill I use for testing - was it time that I made up on the steeper sections or on the flatter parts. I used that hill all the time for climbing training as it offers a nice mix of 6% and 18% for the first 3.5 miles.

I'm also seeing higher average speeds and slightly lower heart rates on the trainer too. Every week a check tire pressure and restistance (coast down time for backwheel from 20mph) for consistancy.
 
why do the PC users not use them for racing ? weight ?

Apologies but it's the first tme I've heard of them
 
giannip said:
why do the PC users not use them for racing ? weight ?

Apologies but it's the first tme I've heard of them
Lot's of reasons. First, they would be illegal for some racing, track most notably. Mostly, I think, because they don't feel up to speed on them enough and their mind set is "regular cranks are better for racing because of the weight factor". Weight is probably the main excuse people use, I think. Another reason that some may not race on them is to not alert their competition to them. The longer their competition is in the dark about them the bigger advantage they will have. Anyhow, I suspect there are as many reasons are there are people. Maybe some of them will speak up as it is clear there are some here.
 
swampy1970 said:
I do have a question for Frank though. Is it a physical impossibility to ride out of the saddle when on a trainer? The "family jewels" would appreciate me standing up every once in a while. :)
Sorry, I missed answering this.

There are two secrets to getting out of the saddle on PowerCranks. You have to understand the different coordination and you have to understand how to control the pedal speed when you come out of the saddle.

To understand the different coordination come out of the saddle and pedal one legged. Pay attention to how you are using your hamstrings more in getting the pedals up.

There are two ways of keeping the pedal speed under control. Use bigger gears and putting a lot of body weight on the handle bars. Every lb on the handlebar is one pound off the pedal.

Once you have done it once then you will be able to do it again and again and soon, without thinking about it.
 
Fday said:
Sorry, I missed answering this.

There are two secrets to getting out of the saddle on PowerCranks. You have to understand the different coordination and you have to understand how to control the pedal speed when you come out of the saddle.

To understand the different coordination come out of the saddle and pedal one legged. Pay attention to how you are using your hamstrings more in getting the pedals up.

There are two ways of keeping the pedal speed under control. Use bigger gears and putting a lot of body weight on the handle bars. Every lb on the handlebar is one pound off the pedal.

Once you have done it once then you will be able to do it again and again and soon, without thinking about it.
Thanks! I'll give it a go.
 
Fday said:
How our customers use the product is all over the map despite our best efforts to use them as we feel is optimum. Regardless of what we feel is best I accept that most of our customers use them in a manner they feel will be optimum for them. They pay their money, they can use them as the want. My impression is that most of our customers use regular cranks at least some of the time regularly, . Many go exclusive during the off season then part time during the season. Others are part-time from the get go. Only a hand full a exclusive use all the time, including racing.

Now, regarding data, I have none other than the anecdotal data I get from grilling customers who I happen to talk to about their experiences. My expectation is that it is sort of like training in general. The more base you have the slower you lose your ability if you stop training. I think the same is true of the PC pedaling pattern. So, if you have 6 weeks on them and then do an Ironman 112 bike race you can expect to be pretty much back to your earlier pedaling style by mile 25. If you have 2 years and 20,000 miles on them you can expect your pedaling style will remain good for the entire race.

One thing is clear, people who used them quite a bit, stopped during the season, and then get back on them the next off season, do not start from the same "zero" level they were at when they first started them. So, it is clear, while they have lost something, they have not even come close to losing everything. That suggests to me that they continue to pedal the pattern and use the muscles more than they did before PC's but less than the PC's force them to do, so they lose something but not everything.

So, the only data I have is anecdotal (plus the Italian study which doesn't tell us much because it was so short) but it is better than nothing. Does that answer your question?
Just wanted to shear my experience with powercranks. After training a lot on the cranks the past 16 months (around 17.000 km. total) I have decided to train AND race on regular cranks this season. I have made a "base" on powercranks during the fall and early winter, and then uninstalled the PC´s in the end of January. I still feel like I am riding the "Powercranks" way, and when I freewheel I still get the "kick" when the second pedal goes to the top of the stroke by itself unexpected :)

I, of course have no way of telling if I am already slowly reverting back to "regular" pedaling, but at least it doesn't feel that way - and I am really happy with the changes PC's have made for me.

My plan in the next years will probably be to go almost exclusive PC's during the early off-season (trying to ride around 5000 km. on the cranks) and then do all of my training on regular cranks in the racing season. I know Frank thinks that the PC's are used best when training almost exclusively on them - but this just doesn't work for me.

The longest I have been off the powercranks is around 4 weeks in a row and after that I started riding on the Powercranks like I rode them yesterday - I'm not sure the ability is disappearing that fast, as long as the base on the Powercranks is large enough (and the initial adaption-phase is finished).
 
LarsEjaas said:
Just wanted to shear my experience with powercranks. After training a lot on the cranks the past 16 months (around 17.000 km. total) I have decided to train AND race on regular cranks this season. I have made a "base" on powercranks during the fall and early winter, and then uninstalled the PC´s in the end of January. I still feel like I am riding the "Powercranks" way, and when I freewheel I still get the "kick" when the second pedal goes to the top of the stroke by itself unexpected :)

I, of course have no way of telling if I am already slowly reverting back to "regular" pedaling, but at least it doesn't feel that way - and I am really happy with the changes PC's have made for me.

My plan in the next years will probably be to go almost exclusive PC's during the early off-season (trying to ride around 5000 km. on the cranks) and then do all of my training on regular cranks in the racing season. I know Frank thinks that the PC's are used best when training almost exclusively on them - but this just doesn't work for me.

The longest I have been off the powercranks is around 4 weeks in a row and after that I started riding on the Powercranks like I rode them yesterday - I'm not sure the ability is disappearing that fast, as long as the base on the Powercranks is large enough (and the initial adaption-phase is finished).
I think someone like yourself, who has a pretty substantial base, will revert back very slowly as long as you stay within your PC capabilities. By staying within your PC capabilities I mean, if the highest cadence you can maintain for any length of time is 85 but you get on regular cranks and try to time-trial at a cadence of 95 I think you will find yourself back to the old ways probably before that race is over, simply because you haven't trained that capability yet. Regular cranks seem so "easy" after PC's that it is easy for people to make "stupid" mistakes that hurt their performance during races, when the adrenalin is pumping, that they may not see in training.

The issue I have with training on regular cranks for someone like yourself is I think you will stop the potential for any further PC improvement that might occur during the season. If there is no difference to you between riding PC's and regular cranks I just don't see why you would want to risk any sliding backwards or forego any further potential PC improvement between now and the end of the season. I can understand occasionally training on regular cranks and I can understand racing on regular cranks, but I don't understand the racing rational of giving up the PC's entirely during the season if one is adequately adapted.
 
Fday said:
So, the only data I have is anecdotal (plus the Italian study which doesn't tell us much because it was so short) but it is better than nothing.
Frank,

Is it also correct to say that you also have no power meter data showing that someone puts out more power while using Power Cranks (assuming the adjustment period has completed)?
 
Steve_B said:
Frank,

Is it also correct to say that you also have no power meter data showing that someone puts out more power while using Power Cranks (assuming the adjustment period has completed)?
No, we have tons of power data that show very large power increases. My "lack of data" only goes to what happens when people stop using them. Most of our power data is anecdotal although there have been a few independent studies showing same, the most notable one being Dixon, who showed increases in both power (11%) and VO2max (15%) in only 6 weeks.

Today got an email from a customer who reports "I have been using the power cranks since November. I have noticed a 20% increase in wattage over a 30' time trial test with really no hard training such as intervals".

Reports like this are received routinely by us.
 
Fday, I have them and use them indoors for a specific purpose and mix them with roller work and weights. My only negative observation/suggestion would be to make a version that the pedals lock into the correct forward position. It is hard to get back into correct position when your hip flexors are on fire. Being a fast twitch guy , I simply dont ride enough to fully adapt. FWIW , I can sprint on them but tempo is brutal.