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  #21  
Old 02-23-13, 17:46
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Originally Posted by FrankDay View Post
I guess you can take that point but most researchers are interested in getting positive results.
Exercise physiologists will look for any improvement but a sport scientist will look for performance gains at the highest level possible.

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Since it is easier to get results in the lesser trained it seems to me, if I wanted to prove a concept that I would start there.
If you wanted to delude yourself over the potential of anything.

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Once we understand that the concept works then one can test to see what is required to get results in the highly trained.
A lazy approach.

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So, we know from Luttrell that 6 weeks of part-time use can result in demonstrable benefits in the not very well trained but active cyclist but that similar intervention doesn't work in that period of time in more elite cyclists.
No change in IAT in the experimental group. This was the only test of cycling fitness they performed.

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That is not proof that the concept doesn't work but only that was not enough intervention to demonstrate improvement in highly trained cyclists.
Where other interventions show a positive adaptation is not only possible in a matter of days but after 5-6 weeks the performance gains start to taper off.

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But, Dixon was able to demonstrate that 6 weeks is enough time to demonstrate improvement in highly trained cyclists if an immersion intervention is used.
No details available about whether they were highly trained. Their VO2max scores would suggest otherwise. And of course no control group. Need to compare with a control group using normal cranks and a matched workload.
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  #22  
Old 02-23-13, 20:39
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The Impact of 10 weeks of Independent Cycle Crank use on
Cycle Performance
Robert M. Otto, FACSM, Laura Walsh, Jessica Marra, Christopher
Kushner, Alicia Diaz, Carolyn Richardson, John W. Wygand.
Adelphi University, Garden City, NY.
Email: otto@adelphi.edu
(No relationships reported)
Improvements in cycle performance may be a result of enhanced efficiency and/or a greater
power output. Cyclists strive to achieve both by over-distance training, high intensity
training, and specific cycle drills. Special products that claim to improve performance
by offering improved aerodynamics, reduced total cycle mass, better force transfer to the
crank, or providing biomechanical feedback rely on a paucity of research.
PURPOSE: To evaluate the effect of ten weeks of using independent cycle cranks
(ICC) on cycling performance as measured by oxygen efficiency (OxE), time trial
performance (TT), and body composition (BC).
METHODS: After a medical/health screening, thirty triathletes (16 male, 14 female)
(age 43.2 [range 25-54 yr], ht 176 [range 160-188 cm], and body mass 73.3 [range
54.3-97.7.5 kg]), participated in familiarization trials including DEXA scan, electronic
cycle ergometer based steady state OxE trial and a time trial. Identical testing was
performed during the familiarization trial, pre-test (within one week) and the posttest
(ten weeks later). After the pre-test trial, subjects were randomly assigned to one
of three groups (C = control, 90 = 90 min/wk and 180 = min/wk). For ten weeks all
subjects exercised (swim, cycle, run) a minimum of eight hours per week. All groups
cycled a minimum of three hours/week with C in fixed cranks, 90 for 90 min fixed and
90 min ICC, and 180 for 180 min ICC.
RESULTS: Statistical analysis by ANOVA (P<.05) reveals no significant difference among or
between trials.
CONCLUSION: The use of independent cycle crank arms for a maximum of 30 hours
within ten weeks, requires the user to apply force independent of crank position, but
does not result in quantifiable changes in cycle efficiency or performance
This study bears repeating as it was carried out over 10 weeks. Still no improvement in performance.
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  #23  
Old 02-23-13, 23:15
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From Jobson (2012)

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Therefore, the question arises as to whether or not changes in pedalling technique can affect cycling efficiency if participants are given the opportunity to adapt to a new pedalling style. To address this question, several authors have used the decoupled crank paradigm to investigate the issue longitudinally. Training with decoupled cranks forces the cyclist to actively pull on the pedal during the upstroke, with potential implications for pedalling technique and cycling efficiency. Luttrell & Potteiger (2003) reported that 6 weeks of training with decoupled cranks resulted in improved cycling efficiency. However, the participant selection in this study was poorly controlled, and thus, the meaningfulness of these results is limited. Williams et al. (2009) quantified the effect of training with decoupled cranks on pedalling technique and cycling efficiency in a more controlled fashion. These authors found no significant effects of training with decoupled cranks on cycling efficiency. Expanding on these results, Bhm et al. (2008) showed that training with decoupled cranks can change certain aspects of the pedalling technique without changing physiological variables. Together, the experimental evidence suggests that the acquisition of new pedalling techniques does not result in significant increases in gross efficiency in the short to medium term.
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  #24  
Old 02-25-13, 00:39
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The balance of the research is clear. PowerCranks are worthless for trained cyclists.
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  #25  
Old 02-25-13, 01:55
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Originally Posted by BroDeal View Post
The balance of the research is clear. PowerCranks are worthless for trained cyclists.
I'm not very good at reading between the lines. What are you trying to say?
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  #26  
Old 02-27-13, 20:09
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Originally Posted by FrankDay View Post
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.
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  #27  
Old 05-15-13, 18:17
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Originally Posted by FrankDay View Post
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 ?
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  #28  
Old 05-15-13, 19:36
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Originally Posted by coapman View Post
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 (PCs) and 8 subjects committed to ride ConnectedCranks (CCs) 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
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  #29  
Old 05-15-13, 19:47
FrankDay FrankDay is offline
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Originally Posted by sciguy View Post
The most recent update I can find:

Rolling Update:

3rd September 2012

The study has 8 subjects committed to ride PowerCranks (PCs) and 8 subjects committed to ride ConnectedCranks (CCs) 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.
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  #30  
Old 05-15-13, 21:41
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Originally Posted by FrankDay View Post
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.
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