The Powercrank Thread

[coapman]

So, there is stuff to be learned from those negative studies. It just isn't what you think it is.

PC training cannot increase power output. The most difficult sector while using PC's is between 9 and 12 o'c. With standard cranks there is no difficulty here because all that's required is the raising of the knee from after BDC as the pedal is moving upwards, this results in a swinging lower leg which can be easily steered by the rising pedal through this difficult sector without any resistance against the rising pedal. Trying to drag an independent pedal/crank around 10 and 11 o'c with the lower leg can be very stressful on the hip flexors, what is there to be gained by this unnecessary workload.

 

[Boeing]

you two need to get a room

 

[coapman]

Physiological responses to training using PowerCranks on trained cyclists.

Stephen J. Dixon, Michael F. Harrison, Kenneth A. Seaman, Stephen S. Cheung and J. Patrick Neary. University of New Brunswick, Fredericton, NB; Dalhousie University, Halifax, NS; University of Regina, Regina, SK

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 adaptations 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 wks 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. Supported by NSERC

Oral presentation at Canadian Society of Exercise Physiologists meeting, November 2006. unpublished.

Any feedback from the POWERCRANK research that took place in Galway over the winter and spring months ?

 

[sciguy]

Any feedback from the POWERCRANK research that took place in Galway over the winter and spring months ?

The most recent update I can find:

Rolling Update:

3rd September 2012

The study has 8 subjects committed to ride PowerCranks (PC’s) and 8 subjects committed to ride ConnectedCranks (CC’s) for 6 hours minimum per week for six months
All subjects will provide Speed, Cadence and Heart Rate data for the 6 hours per week
Subjects will be baseline tested before study and every month for six months there after.

It's interesting what data the subjects will and will not be providing.

Hugh

 

[FrankDay]

The most recent update I can find:

Rolling Update:

3rd September 2012

The study has 8 subjects committed to ride PowerCranks (PC’s) and 8 subjects committed to ride ConnectedCranks (CC’s) for 6 hours minimum per week for six months
All subjects will provide Speed, Cadence and Heart Rate data for the 6 hours per week
Subjects will be baseline tested before study and every month for six months there after.

It's interesting what data the subjects will and will not be providing.

Hugh

I inquired about this and was told there had been some personal or technical problems and the study never started. Can't remember exactly what the problem was. the researcher wanted to know if we wanted him to send the cranks back or he thought he could do it again later this year. We told him to go for it.

 

[CoachFergie]

I inquired about this and was told there had been some personal or technical problems and the study never started. Can't remember exactly what the problem was. the researcher wanted to know if we wanted him to send the cranks back or he thought he could do it again later this year. We told him to go for it.

No great loss. The guy posted on Andy Coggan's Facebook that he was going to show us that uncoupled cranks worked. Clearly biased.

 

[Oldman]

The balance of the research is clear. PowerCranks are worthless for trained cyclists.

But what is worthwhile is that these two finally did get a room...

 

[CoachFergie]

http://www.frontiersin.org/Exercise_Physiology/10.3389/fphys.2013.00232/abstract

Bit of a no-brainer showing that independent cranks and normal cranks alter the way muscles work while pedalling.

More speculation about long term benefits. The benefits would only apply if one was competing using independent cranks in competition. If not the case then one is better training specifically towards the goal.

 

[CoachFergie]

As revealed by the large 95% confidence intervals on
Figures3, 4, there was a high inter-individual variability in the
way the participants adapted to these new mechanical constraints.

Mechanical constraints. Impose them and the body adapts. Remove them and the body adapts to the original demands. Fernandez-Pena (2009) showed this quite well.

 

[FrankDay]

http://www.frontiersin.org/Exercise_Physiology/10.3389/fphys.2013.00232/abstract

Bit of a no-brainer showing that independent cranks and normal cranks alter the way muscles work while pedalling.

More speculation about long term benefits. The benefits would only apply if one was competing using independent cranks in competition. If not the case then one is better training specifically towards the goal.

You really don't see the big picture here do you.

In another thread you and others are waxing on about how easy pedaling is and that it can be learned in 5 minutes. Well, this and other studies show that there are many different coordination patterns that can make the pedals go around. Just because you can make them go around doesn't mean that the coordination pattern you are using is the best of the bunch. Now, if it can be shown that the coordination pattern that is learned from training on independent cranks is superior from the one that we learned pedaling on regular cranks then the question would be: can I learn to pedal my regular cranks (assuming you want to continue to race on regular cranks) in this "better" fashion. If Noels "linear" technique is shown to be superior to them all everyone will be wanting to know how to learn it.

Of course, no technique has yet to be proven superior to any other YET so, as they say: ignorance is bliss. But, when one is, everyone should then be asking: How can I learn this better technique? My guess is Fergie, you will be one of the last asking that question.

 

[CoachFergie]

The way we pedal is mechancally constrained by the type of crank we use. What we can do is choose how long we pedal and how intense we pedal. Doing enough of that without acumulating large amounts of fatigue is where real performance gains are made.

 

[FrankDay]

The way we pedal is mechancally constrained by the type of crank we use. What we can do is choose how long we pedal and how intense we pedal. Doing enough of that without acumulating large amounts of fatigue is where real performance gains are made.

The only thing that is constrained is the point of the foot that is touching the pedal is constrained to move in a circle. The muscles that are used to force the motion can use a whole variety of coordination techniques to make it happen and, guess what, the foot will still move in a circle. The only question is with what power and what efficiency. The two remaining questions are 1. what is the best coordination pattern to use for best power and best efficiency. and 2. what is the best training technique to achieve that best coordination pattern. The other questions you ask are still pertinent regardless of the pedaling technique used.

 

[CoachFergie]

The two remaining questions are 1. what is the best coordination pattern to use for best power and best efficiency. and 2. what is the best training technique to achieve that best coordination pattern. The other questions you ask are still pertinent regardless of the pedaling technique used.

You, or anyone has failed to provide any data, published or unpublished that shows that changing the coordination pattern from a natural pedalling stroke is significantly more powerful or more efficient.

Best training technique is the one that prepares a cyclist for the demands of their event.

They are pertinent because pedalling technique plays such a tiny role in the overall performance in cycling.

 

[FrankDay]

You, or anyone has failed to provide any data, published or unpublished that shows that changing the coordination pattern from a natural pedalling stroke is significantly more powerful or more efficient.

Yes, that is why there is a debate. If good data existed to support one methor or another the debate would have ended long ago.

Best training technique is the one that prepares a cyclist for the demands of their event.

I would think the best training technique is the one that prepares the athelte to win their particular event.

They are pertinent because pedalling technique plays such a tiny role in the overall performance in cycling.

If everyone pedals the same, that is the case. However, it isn't clear that using a better pedaling technique than the competition cannot be a deciding factor. Why would any truly competitive athlete want to give up any possible edge? But, some apparently do because it is either too weird or too much work.

 

[CoachFergie]

Yes, that is why there is a debate. If good data existed to support one methor or another the debate would have ended long ago.

Pretty one sided debate when the other side has on speculation and marketing fluff as evidence.

However, it isn't clear that using a better pedaling technique than the competition cannot be a deciding factor. Why would any truly competitive athlete want to give up any possible edge? But, some apparently do because it is either too weird or too much work.

A whole field of science devoted to sports performance and cycling is one of the easiest measured sport. Some great new studies come out on a monthly basis that allow us to make new gains all the time. None in the area of pedalling sorry.

But keep trying to convince us, it's so amusing.

 

[FrankDay]

Pretty one sided debate when the other side has on speculation and marketing fluff as evidence.

No, the other sied has a theory and anecdotal evidence. Pretty much the same as your side.

A whole field of science devoted to sports performance and cycling is one of the easiest measured sport. Some great new studies come out on a monthly basis that allow us to make new gains all the time. None in the area of pedalling sorry.

LOL. Lets look at the world hour record. If there were new gains to be made in the literature "all the time" where are they reflected in any of the cycling world records, especially the iconic hour record.

 

[CoachFergie]

No, the other sied has a theory and anecdotal evidence.

Yeah right, theories with only a vivid imagination to back it, even your anecdotal evidence is pretty weak. Courtney Ogden wins a race on short cranks. Completely meaningless, proof of nothing.

Lets look at the world hour record. If there were new gains to be made in the literature "all the time" where are they reflected in any of the cycling world records, especially the iconic hour record.

You don't think the UCI killed that by restricting it to Merckx Position?

All other World Records are consistently coming down. Only thing going backwards is the speed of the Tour de France but that is because they are slowly getting rid of the powerc..., sorry, drug users from the sport.

 

[coapman]

Have a look at " Cycling Forums " I am waiting for an answer.

 

[FrankDay]

Have a look at " Cycling Forums " I am waiting for an answer.

Was this directed to me? Answer to what?

 

[coapman]

Was this directed to me? Answer to what?

An answer to a question I asked SWAMPY on " cycling forum ". Like the answers or claims etc on the SLOWTWITCH forum at the present time from PC users, nobody believes there is an increase in torque in the sectors where you claim most advantages occur at TDC AND BDC.

 

[FrankDay]

An answer to a question I asked SWAMPY on " cycling forum ". Like the answers or claims etc on the SLOWTWITCH forum at the present time from PC users, nobody believes there is an increase in torque in the sectors where you claim most advantages occur at TDC AND BDC.

Huh? Anyhow, what anyone believes or not is really not persuasive since no one actually measures these forces. With the soon (hopefully) availability of the iCranks this knowledge void will disappear.

Further, the total power generated around the pedaling circle is the sum of the instantaneous powers generated at each point around the circle. Any increase at any point around the circle (everything else remaining constant) result in an overall increase. If you, or anyone else, wants to concentrate on increasing power over only a portion of the circle so be it. I, for one, will take power improvement wherever I can get it. We each, now, have to make that choice. Choose wisely if you are serious.

 

[coapman]

Further, the total power generated around the pedaling circle is the sum of the instantaneous powers generated at each point around the circle. Any increase at any point around the circle (everything else remaining constant) result in an overall increase. If you, or anyone else, wants to concentrate on increasing power over only a portion of the circle so be it. I, for one, will take power improvement wherever I can get it. We each, now, have to make that choice. Choose wisely if you are serious.

When using PC's or the circular style everything else does not remain constant, power application between 2 and 4 o'c is reduced and it is the power applied in this sector that accelerates the speed of the bike. On a flat surface from the time the crank passes 4 o'c until the other crank applies torque at 2, bike speed is decreasing regardless of what is happening elsewhere in the pedalling circle. By reducing power application in this 2-4 sector you are reducing the acceleration of the bike. Obviously by more than doubling that 2-4 power effect which can be done by extending it from 11-4, you are not only increasing bike acceleration time in each pedalling stroke but also reducing deceleration time. Choose wisely if you are serious.

 

[FrankDay]

When using PC's or the circular style everything else does not remain constant, power application between 2 and 4 o'c is reduced and it is the power applied in this sector that accelerates the speed of the bike. On a flat surface from the time the crank passes 4 o'c until the other crank applies torque at 2, bike speed is decreasing regardless of what is happening elsewhere in the pedalling circle. By reducing power application in this 2-4 sector you are reducing the acceleration of the bike. Obviously by more than doubling that 2-4 power effect which can be done by extending it from 11-4, you are not only increasing bike acceleration time in each pedalling stroke but also reducing deceleration time. Choose wisely if you are serious.

It doesn't matter what pedaling style one uses there will always be some variation in the pedaling forces applied around the circle. Assuming one is at a constant speed whenever the sum of the two pedal forces is above the resistive forces the bike will accelerate and whenever they are less the bike will decelerate around the average speed of the bicycle. It is simple newtonian physics.

There is nothing that says that increasing force at any part of the circle requires reducing force at another part of the circle unless one is maintaining a constant power and cadence. If you think that just because one unweights more requires them to push less why isn't it that if I push more I don't have to unweight less?

 

[coapman]

It doesn't matter what pedaling style one uses there will always be some variation in the pedaling forces applied around the circle. Assuming one is at a constant speed whenever the sum of the two pedal forces is above the resistive forces the bike will accelerate and whenever they are less the bike will decelerate around the average speed of the bicycle. It is simple newtonian physics.

There is nothing that says that increasing force at any part of the circle requires reducing force at another part of the circle unless one is maintaining a constant power and cadence. If you think that just because one unweights more requires them to push less why isn't it that if I push more I don't have to unweight less?

Total unweighting when used with the natural pedaling technique can be a stress free and pain free action, why does PC pedaling cause so much stress and pain.

 

[FrankDay]

Total unweighting when used with the natural pedaling technique can be a stress free and pain free action, why does PC pedaling cause so much stress and pain.

Huh? Most peoples natural pedaling style does not involve total unweighting but, rather, partial unweighting. Making someone use muscles way beyond where they are trained always is stressful and painful. Ask your sedentary grandmother to run a marathon and tell me if she thinks it was stressful and painful. But, once those under trained "unweighting" muscles approach the same level of training as all the other muscles PC training is no more stressful or painful than normal training. The stress and pain is temporary.