New study shows leg flexion less efficient than extension.

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

One poorly performed study by Luttrell, that was published in JSCR, and was laughed off the stage when presented at ACSM because they couldn't show they had calibrated the gas analysis equipment properly, and several subsequent studies (Burns, and Williams studies for a start) showed no improvement in efficiency.

Ah Frank's beloved Luttrell and Potteiger study. I was there when it was presented at ACSM. There was a line at the mic with people waiting to ask questions. I didn't even get to ask a question before the moderator closed questions and moved on to the next speaker. One guy accused the speaker (I think Potteiger presented) of presenting a paid infomercial. I've never seen anything like the response to that presentation before or since.
As you mention there are likely a number of issues with that study. For me, the main issue is the use of the pan loaded Monark. Belts heat up and change friction over time. When we have used a pendulum loaded Monark we typically have a student designated to do nothing but keep an eye on the pendulum and constantly tweak it to hold it where we want it. With the pan load you have no idea what the resistance really is unless you have load cells on both ends of the belt. MacIntosh has a paper showing how inaccurate that system is.
Also, that 10% difference they report is so large that if it were real it would show up in other studies as you said. A single drop of lube (intentional or inadvertent) on the flywheel would go a long way to explain the results. When we lube the belts on our pendulum loaded ergs they require much more tension for the same load. Maybe the chain was making noise and the student running the study spayed lube on it and accidentally got some on the flywheel. And, as you mentioned there may have been met cart calibration issues. There are no doubt many reasons that paper only made it in to the lower tier JSCR.
Bad science gets published now and again but "truth will out" eventually.

Thanks, you're not the first to recall how badly received that paper was.

LOL. Let's see if we can come up with a scenario that might explain why that paper was so "badly received." Perhaps there was some very well known researcher there who had expressed strong views about the topic such that, if Lutrell was correct, it would be obvious to the world he cares about that he had been both petty and, more importantly, WRONG! Anyhow, it doesn't matter if the paper was badly received at some meeting or not. It is what it is and it stands on its own. Nothing since then has shown the data or protocol to be seriously flawed.

 

[PhitBoy]

Re: New study shows leg flexion less efficient than extensio

Nothing since then has shown the data or protocol to be seriously flawed.

Yeahbut....

Int J Sports Physiol Perform. 2009 Mar;4(1):18-28.
Cycling efficiency and performance following short-term training using uncoupled cranks.
Williams AD1, Raj IS, Stucas KL, Fell JW, Dickenson D, Gregory JR.
Author information
Abstract
OBJECTIVES:

Uncoupled cycling cranks are designed to remove the ability of one leg to assist the other during the cycling action. It has been suggested that training with this type of crank can increase mechanical efficiency. However, whether these improvements can confer performance enhancement in already well-trained cyclists has not been reported.
METHOD:

Fourteen well-trained cyclists (13 males, 1 female; 32.4 +/- 8.8 y; 74.5 +/- 10.3 kg; Vo2max 60.6 +/- 5.5 mL.kg-1.min-1; mean +/- SD) participated in this study. Participants were randomized to training on a stationary bicycle using either an uncoupled (n = 7) or traditional crank (n = 7) system. Training involved 1-h sessions, 3 days per week for 6 weeks, and at a heart rate equivalent to 70% of peak power output (PPO) substituted into the training schedule in place of other training. Vo2max, lactate threshold, gross efficiency, and cycling performance were measured before and following the training intervention. Pre- and posttesting was conducted using traditional cranks.
RESULTS:

No differences were observed between the groups for changes in Vo2max, lactate threshold, gross efficiency, or average power maintained during a 30-minute time trial.
CONCLUSION:

Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.


Int J Sports Physiol Perform. 2012 Jun;7(2):113-20. Epub 2011 Nov 29.
Effects of short-term training with uncoupled cranks in trained cyclists.
Burns JM1, Peiffer JJ, Abbiss CR, Watson G, Burnett A, Laursen PB.
Author information
Abstract
PURPOSE:

Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.
METHODS:

Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.
RESULTS:

No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.
CONCLUSIONS:

Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

Effect of Independent Cycle Crank Training on Running Economy and VO2 Max in Distance Runners

Dale R. Wagner, Edward M. Heath, Aaron W. Smith

Human Movement Science, Utah State University, Logan, UT

ABSTRACT

Wagner DR, Heath EM, Smith AW. Effect of Independent Cycle Crank Training on Running Economy and VO2 Max in Distance Runners. JEPonline 2013;16(1):1-9. The purpose of this study was to examine the changes in running economy and maximal oxygen consumption (VO2 max) of cross-country runners with cross-training on the PowerCranks™. Seven men and 6 women completed 6 wks of stationary cycle ergometer training using either the PowerCranks™ or the standard cranks (control group). The subjects trained 3 d∙wk-1 at 60 rev·min-1 at 3 to 3.5 kg for 30 min, which increased to 40 min after the 3rd wk and 50 min after the 4th wk, with a 48-h minimum between training sessions. Pre-and post-running economy and VO2 max were measured. There were no significant differences in running economy or VO2 max after training in either the control or the PowerCranks™ group. Further, the difference in change scores for running economy between the PowerCranks™ (0.102 ± 0.101 L∙min-1) and the control (0.010 ± 0.108 L∙min-1) groups was not significant (P=0.15). Cross-training for 6 wks with independent cycle cranks 3 d∙wk-1 had no effect on the running economy or VO2 max of highly-trained collegiate distance runners.

And slightly different but related

Korff T, Romer LM, Mayhew I, Martin JC
Brunel University, Centre for Sports Medicine and Human Performance, Uxbridge, Middlesex, UK. thomas.korff@brunel.ac.uk
Medicine and Science in Sports and Exercise [2007, 39(6):991-995]
Type: Journal Article, Research Support, Non-U.S. Gov't
DOI: 10.1249/mss.0b013e318043a235
Abstract Highlight Terms
No biological terms identified
PURPOSE: To optimize endurance cycling performance, it is important to maximize efficiency. Power-measuring cranks and force-sensing pedals can be used to determine the mechanical effectiveness of cycling. From both a coaching and basic science perspective, it is of interest if a mechanically effective pedaling technique leads to greater efficiency. Thus, the purpose of this study was to determine the effect of different pedaling techniques on mechanical effectiveness and gross efficiency during steady-state cycling.

METHODS: Eight male cyclists exercised on a cycle ergometer at 90 rpm and 200 W using four different pedaling techniques: preferred pedaling; pedaling in circles; emphasizing the pull during the upstroke; and emphasizing the push during the downstroke. Each exercise bout lasted 6 min and was interspersed with 6 min of passive rest. We obtained mechanical effectiveness and gross efficiency using pedal-reaction forces and respiratory measures, respectively.

RESULTS: When the participants were instructed to pull on the pedal during the upstroke, mechanical effectiveness was greater (index of force effectiveness=62.4+/-9.8%) and gross efficiency was lower (gross efficiency=19.0+/-0.7%) compared with the other pedaling conditions (index of force effectiveness=48.2+/-5.1% and gross efficiency=20.2+/-0.6%; means and standard deviations collapsed across preferred, circling, and pushing conditions). Mechanical effectiveness and gross efficiency during the circling and pushing conditions did not differ significantly from the preferred pedaling condition.

CONCLUSIONS: Mechanical effectiveness is not indicative of gross efficiency across pedaling techniques. These results thereby provide coaches and athletes with useful information for interpreting measures of mechanical effectiveness.

Int J Sports Med. 2008 Oct;29(10):817-22. doi: 10.1055/s-2008-1038374. Epub 2008 Apr 17.
Effects of pedal type and pull-up action during cycling.
Mornieux G, Stapelfeldt B, Gollhofer A, Belli A.
Source
Institut für Sport und Sportwissenschaft, Universität Freiburg, Freiburg, Germany. guillaume.mornieux@sport.uni-freiburg.de
Abstract
The aim of this study was to determine the influence of different shoe-pedal interfaces and of an active pulling-up action during the upstroke phase on the pedalling technique. Eight elite cyclists (C) and seven non-cyclists (NC) performed three different bouts at 90 rev . min (-1) and 60 % of their maximal aerobic power. They pedalled with single pedals (PED), with clipless pedals (CLIP) and with a pedal force feedback (CLIPFBACK) where subjects were asked to pull up on the pedal during the upstroke. There was no significant difference for pedalling effectiveness, net mechanical efficiency (NE) and muscular activity between PED and CLIP. When compared to CLIP, CLIPFBACK resulted in a significant increase in pedalling effectiveness during upstroke (86 % for C and 57 % NC, respectively), as well as higher biceps femoris and tibialis anterior muscle activity (p < 0.001). However, NE was significantly reduced (p < 0.008) with 9 % and 3.3 % reduction for C and NC, respectively. Consequently, shoe-pedal interface (PED vs. CLIP) did not significantly influence cycling technique during submaximal exercise. However, an active pulling-up action on the pedal during upstroke increased the pedalling effectiveness, while reducing net mechanical efficiency.

 

[CoachFergie]

 

[JamesCun]

Re: Re:

Nope, at least on a bicycle.
...you unweight by pushing down then pulling up on the skis.

Glad we agree that unweighting is pulling up with force. Confused why you would state that it wasn't pulling up. Maybe you are starting to talk in so many circles out so many sides of your mouth that you can't keep things straight.

 

[JamesCun]

Re: New study shows leg flexion less efficient than extensio

Instead, people see a result that doesn't conform with their bias and just discount it.

Take a look in the mirror. The one with the bias and something to gain is you, Frank.

Why is this result so large? Coyle demonstrated a similar efficiency improvement in a trained cyclist (the best in the world) albeit over a longer length of time. The fact that this result is so large should be a reason for other to try to replicate the study. No one has done that. Some have done similar studies but not the same study. Either doing less time, or using a more experienced cohort that could explain their failure and Luttrell's positive finding.

Now we are talking about Lance Armstrong over years of training and doping? That is a super valid comparison to a short term study.

Yep, and until someone replicates that study and demonstrates the finding was the result of an error it remains a valid study...The problem is you guys are really up the creek without a paddle if someone replicates the study and gets the same or similar results. All your smartness will be shown for what it is, a bunch of bias. Replicate the study and see what happens (except, if you do, please also measure pedal forces so we can document whether and how pedal forces changed by the intervention).

Really Frank, a study is valid until another study proves it invalid? That isn't how things work in the real world. If the methods aren't valid, the study isn't valid. You don't need another study to discount one that was done poorly. Just like we don't need another study like Dixon to know that Dixon wasn't a valid study.

 

[backdoor]

Re: Re:

Nope, at least on a bicycle.
...you unweight by pushing down then pulling up on the skis.

Glad we agree that unweighting is pulling up with force. Confused why you would state that it wasn't pulling up. Maybe you are starting to talk in so many circles out so many sides of your mouth that you can't keep things straight.

Unweighting means doing no more than lifting the weight of your leg/foot off the pedal in the same way as you lift your foot off the ground when walking or running. Pulling up means applying or trying to apply upward torque to the rising pedal.

 

[FrankDay]

Re: Re:

Nope, at least on a bicycle.
...you unweight by pushing down then pulling up on the skis.

Glad we agree that unweighting is pulling up with force. Confused why you would state that it wasn't pulling up. Maybe you are starting to talk in so many circles out so many sides of your mouth that you can't keep things straight.

Of course it is pulling up, pulling up against gravity. Weight is caused by gravity. Unweighting means going against gravity. It is like resting one foot on a bathroom scale and lifting it up and watching the weight number go down. It can go down a little or a lot (to zero) depending upon how hard one wants to lift. Only when one "pulls up" enough to fully overcome gravity can one apply any positive upward force on the pedals on the backstroke. Everyone unweights when riding a bike. To say otherwise simply is admitting you don't understand what everyone does when riding a bicycle.

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

Instead, people see a result that doesn't conform with their bias and just discount it.

Take a look in the mirror. The one with the bias and something to gain is you, Frank.

I wasn't at that meeting. I was simply trying to visualize a scenario that could explain such a vehement reaction to a simple study at a scientific meeting.

Why is this result so large? Coyle demonstrated a similar efficiency improvement in a trained cyclist (the best in the world) albeit over a longer length of time. The fact that this result is so large should be a reason for other to try to replicate the study. No one has done that. Some have done similar studies but not the same study. Either doing less time, or using a more experienced cohort that could explain their failure and Luttrell's positive finding.

Now we are talking about Lance Armstrong over years of training and doping? That is a super valid comparison to a short term study.

In the history of cycling I am only aware of three studies that have demonstrated cycling efficiency improvements in trained cyclists. Armstrong, Lutrell, and the OP of this thread. Armstrong and the OP are especially intriguing because, in Armstrong's case, no other athlete of similar stature has ever demonstrated a similar improvement. Coyle attributed it to muscular fiber type change from training but if this were the case such changes would be commonplace amongst the pros. It isn't. How else to explain it. One thing we know is that Carmichael told us that Armstrong was working on improving his pedaling technique at the back and top of his stroke during this period. The OP clearly demonstrates that pedaling technique can affect pedaling efficiency, at least that is the only explanation I can come up with. Even though the study had an N=1 and the subject acted as his own control (similar to Dixon) it is still compelling. Lutrell demonstrated a change in efficiency after a period of using a product designed to change technique. While he did not demonstrate how the technique changed he did demonstrate efficiency changes. All of these are related. You may choose to ignore them if you choose but if you are interested in improving efficiency then these studies should get your attention and if one can answer the question as to how these efficiency changes occurred one might understand how to make it happen in everyone. Or, maybe someone spilled some oil on the machines being used or forgot to calibrate the equipment in all of these cases and they all happened to change in the same way.

Yep, and until someone replicates that study and demonstrates the finding was the result of an error it remains a valid study...The problem is you guys are really up the creek without a paddle if someone replicates the study and gets the same or similar results. All your smartness will be shown for what it is, a bunch of bias. Replicate the study and see what happens (except, if you do, please also measure pedal forces so we can document whether and how pedal forces changed by the intervention).

Really Frank, a study is valid until another study proves it invalid?

Yep

That isn't how things work in the real world. If the methods aren't valid, the study isn't valid. You don't need another study to discount one that was done poorly. Just like we don't need another study like Dixon to know that Dixon wasn't a valid study.

While it may not work that way in your real world (obviously) that is how it is supposed to work in the scientific world. It is why researchers took such great care to reproduce the "cold fusion" experiment to see if it could be reproduced. People thought the results probably bogus (if true it would have turned physics upside down) but until it was repeated they couldn't say for sure. Same with Lutrell and Dixon and any other "published" study you don't like. Just cause you don't like it or the results does not invalidate it.

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

Sigh, here we go again.

Nothing since then has shown the data or protocol to be seriously flawed.

Yeahbut....

Int J Sports Physiol Perform. 2009 Mar;4(1):18-28.
Cycling efficiency and performance following short-term training using uncoupled cranks.
Williams AD1, Raj IS, Stucas KL, Fell JW, Dickenson D, Gregory JR.
Author information
Abstract
OBJECTIVES:

Uncoupled cycling cranks are designed to remove the ability of one leg to assist the other during the cycling action. It has been suggested that training with this type of crank can increase mechanical efficiency. However, whether these improvements can confer performance enhancement in already well-trained cyclists has not been reported.
METHOD:

Fourteen well-trained cyclists (13 males, 1 female; 32.4 +/- 8.8 y; 74.5 +/- 10.3 kg; Vo2max 60.6 +/- 5.5 mL.kg-1.min-1; mean +/- SD) participated in this study. Participants were randomized to training on a stationary bicycle using either an uncoupled (n = 7) or traditional crank (n = 7) system. Training involved 1-h sessions, 3 days per week for 6 weeks, and at a heart rate equivalent to 70% of peak power output (PPO) substituted into the training schedule in place of other training. Vo2max, lactate threshold, gross efficiency, and cycling performance were measured before and following the training intervention. Pre- and posttesting was conducted using traditional cranks.
RESULTS:

No differences were observed between the groups for changes in Vo2max, lactate threshold, gross efficiency, or average power maintained during a 30-minute time trial.
CONCLUSION:

Our results indicate that 6 weeks (18 sessions) of training using an uncoupled crank system does not result in changes in any physiological or performance measures in well-trained cyclists.

A couple of problems here. The participants were apparently better trained than the Lutrell cohort. One can theorize that it is easier to improve less experienced cyclists than the more expert cyclists. The authors did not bother to confirm that the intervention was adequate to change pedaling technique to that desired (see below).

Int J Sports Physiol Perform. 2012 Jun;7(2):113-20. Epub 2011 Nov 29.
Effects of short-term training with uncoupled cranks in trained cyclists.
Burns JM1, Peiffer JJ, Abbiss CR, Watson G, Burnett A, Laursen PB.
Author information
Abstract
PURPOSE:

Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independent-clutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal oxygen uptake (VO2max), and muscle-activation patterns.
METHODS:

Sixteen trained cyclists were matched-paired into either an uncoupled-crank or a normal-crank training group. Both groups performed 5 wk of training on their assigned cranks. Before and after training, participants completed a graded exercise test using normal cranks. Expired gases were collected to determine economy of motion, gross efficiency, and VO2max, while integrated electromyography (iEMG) was used to examine muscle-activation patterns of the vastus lateralis, biceps femoris, and gastrocnemius.
RESULTS:

No significant changes between groups were observed for economy of motion, gross efficiency, VO2max, or iEMG in the uncoupled- or normal-crank group.
CONCLUSIONS:

Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks.

Here the intervention was for only 5 weeks. But, the authors did bother to see if the intervention changed technique. What they found is that 5 weeks was inadequate to change technique and, of course, efficiency.

Effect of Independent Cycle Crank Training on Running Economy and VO2 Max in Distance Runners

Dale R. Wagner, Edward M. Heath, Aaron W. Smith

Human Movement Science, Utah State University, Logan, UT

ABSTRACT

Wagner DR, Heath EM, Smith AW. Effect of Independent Cycle Crank Training on Running Economy and VO2 Max in Distance Runners. JEPonline 2013;16(1):1-9. The purpose of this study was to examine the changes in running economy and maximal oxygen consumption (VO2 max) of cross-country runners with cross-training on the PowerCranks™. Seven men and 6 women completed 6 wks of stationary cycle ergometer training using either the PowerCranks™ or the standard cranks (control group). The subjects trained 3 d∙wk-1 at 60 rev·min-1 at 3 to 3.5 kg for 30 min, which increased to 40 min after the 3rd wk and 50 min after the 4th wk, with a 48-h minimum between training sessions. Pre-and post-running economy and VO2 max were measured. There were no significant differences in running economy or VO2 max after training in either the control or the PowerCranks™ group. Further, the difference in change scores for running economy between the PowerCranks™ (0.102 ± 0.101 L∙min-1) and the control (0.010 ± 0.108 L∙min-1) groups was not significant (P=0.15). Cross-training for 6 wks with independent cycle cranks 3 d∙wk-1 had no effect on the running economy or VO2 max of highly-trained collegiate distance runners.

What does a running study have to do with Lutrell. Anyhow, one of the more stupid studies ever done on the PowerCranks. A study of elite runners (national championship cross country team) using the cranks AT A CADENCE OF 60 where one can presume their running cadence averages 90 or above. Since the energy requirement of pumping the legs varies with the square of the cadence. So, an intervention at less than half the effort normally encountered showed no change. Our recommendation for runners is they always ride at a cadence at or above their running cadence. What a useless study.

And slightly different but related

Korff T, Romer LM, Mayhew I, Martin JC
Brunel University, Centre for Sports Medicine and Human Performance, Uxbridge, Middlesex, UK. thomas.korff@brunel.ac.uk
Medicine and Science in Sports and Exercise [2007, 39(6):991-995]
Type: Journal Article, Research Support, Non-U.S. Gov't
DOI: 10.1249/mss.0b013e318043a235
Abstract Highlight Terms
No biological terms identified
PURPOSE: To optimize endurance cycling performance, it is important to maximize efficiency. Power-measuring cranks and force-sensing pedals can be used to determine the mechanical effectiveness of cycling. From both a coaching and basic science perspective, it is of interest if a mechanically effective pedaling technique leads to greater efficiency. Thus, the purpose of this study was to determine the effect of different pedaling techniques on mechanical effectiveness and gross efficiency during steady-state cycling.

METHODS: Eight male cyclists exercised on a cycle ergometer at 90 rpm and 200 W using four different pedaling techniques: preferred pedaling; pedaling in circles; emphasizing the pull during the upstroke; and emphasizing the push during the downstroke. Each exercise bout lasted 6 min and was interspersed with 6 min of passive rest. We obtained mechanical effectiveness and gross efficiency using pedal-reaction forces and respiratory measures, respectively.

RESULTS: When the participants were instructed to pull on the pedal during the upstroke, mechanical effectiveness was greater (index of force effectiveness=62.4+/-9.8%) and gross efficiency was lower (gross efficiency=19.0+/-0.7%) compared with the other pedaling conditions (index of force effectiveness=48.2+/-5.1% and gross efficiency=20.2+/-0.6%; means and standard deviations collapsed across preferred, circling, and pushing conditions). Mechanical effectiveness and gross efficiency during the circling and pushing conditions did not differ significantly from the preferred pedaling condition.

CONCLUSIONS: Mechanical effectiveness is not indicative of gross efficiency across pedaling techniques. These results thereby provide coaches and athletes with useful information for interpreting measures of mechanical effectiveness.

Remember that study that showed that asking people to pull up did not result in the same coordination change as training them on independent cranks? Useless for the purpose you are trying to use it. Additionally, Lutrell trained the riders for a period of time to invoke change. No training here. Not applicable to refute Lutrell

Int J Sports Med. 2008 Oct;29(10):817-22. doi: 10.1055/s-2008-1038374. Epub 2008 Apr 17.
Effects of pedal type and pull-up action during cycling.
Mornieux G, Stapelfeldt B, Gollhofer A, Belli A.
Source
Institut für Sport und Sportwissenschaft, Universität Freiburg, Freiburg, Germany. guillaume.mornieux@sport.uni-freiburg.de
Abstract
The aim of this study was to determine the influence of different shoe-pedal interfaces and of an active pulling-up action during the upstroke phase on the pedalling technique. Eight elite cyclists (C) and seven non-cyclists (NC) performed three different bouts at 90 rev . min (-1) and 60 % of their maximal aerobic power. They pedalled with single pedals (PED), with clipless pedals (CLIP) and with a pedal force feedback (CLIPFBACK) where subjects were asked to pull up on the pedal during the upstroke. There was no significant difference for pedalling effectiveness, net mechanical efficiency (NE) and muscular activity between PED and CLIP. When compared to CLIP, CLIPFBACK resulted in a significant increase in pedalling effectiveness during upstroke (86 % for C and 57 % NC, respectively), as well as higher biceps femoris and tibialis anterior muscle activity (p < 0.001). However, NE was significantly reduced (p < 0.008) with 9 % and 3.3 % reduction for C and NC, respectively. Consequently, shoe-pedal interface (PED vs. CLIP) did not significantly influence cycling technique during submaximal exercise. However, an active pulling-up action on the pedal during upstroke increased the pedalling effectiveness, while reducing net mechanical efficiency.

Same criticism as the above.

Fergie, you simply don't understand what any of these studies say or do but you keep trying to use them to support your bias.

 

[JamesCun]

Re: Re:

Unweighting doesn't mean pulling up with force.

Frank, thanks for the BS condescending crap you wrote in response to my question. To quote the relevant text above, you are the only one here who appears to not understand how gravity works. I suggest you return your degrees and go back to high school and learn the basics.

 

[JamesCun]

Re: New study shows leg flexion less efficient than extensio

In the history of cycling I am only aware of three studies that have demonstrated cycling efficiency improvements in trained cyclists. Armstrong, Lutrell, and the OP of this thread. Armstrong and the OP are especially intriguing because, in Armstrong's case, no other athlete of similar stature has ever demonstrated a similar improvement. Coyle attributed it to muscular fiber type change from training but if this were the case such changes would be commonplace amongst the pros. It isn't. How else to explain it. One thing we know is that Carmichael told us that Armstrong was working on improving his pedaling technique at the back and top of his stroke during this period. The OP clearly demonstrates that pedaling technique can affect pedaling efficiency, at least that is the only explanation I can come up with. Even though the study had an N=1 and the subject acted as his own control (similar to Dixon) it is still compelling. Lutrell demonstrated a change in efficiency after a period of using a product designed to change technique. While he did not demonstrate how the technique changed he did demonstrate efficiency changes. All of these are related. You may choose to ignore them if you choose but if you are interested in improving efficiency then these studies should get your attention and if one can answer the question as to how these efficiency changes occurred one might understand how to make it happen in everyone. Or, maybe someone spilled some oil on the machines being used or forgot to calibrate the equipment in all of these cases and they all happened to change in the same way.

Really, you are now using Armstrong and Carmichael as an example of people who have improved pedalling technique and resulted in efficiency improvements. That is such a load of BS, total bias and speculation on your side to support your bogus claims and product.

Here are some facts 1) Carmichael didn't coach Armstrong 2) Armstrong was on a huge list of drugs and experimental doping techniques. If you want to base something on what Carmichael said about Armstrong, that is about as weak an argument as anyone could ever make. Well done Frank, you've outdone yourself this time.

 

[acoggan]

Re: New study shows leg flexion less efficient than extensio

In the history of cycling I am only aware of three studies that have demonstrated cycling efficiency improvements in trained cyclists.

A couple of slides from a presentation I gave for USA Cycling a few years ago. I'm sure that there are more studies now (although obviously not all of these utilized trained cyclists, nor did they necessarily show ongoing improvement year-over-year...just making the point that the notion that cycling efficiency is immutable is questionable at best).

P.S. The earliest study that I have been able to locate that demonstrates an improvement in cycling efficiency with training dates from the 1930s.

 

[FrankDay]

Re: Re:

Unweighting doesn't mean pulling up with force.

Frank, thanks for the BS condescending crap you wrote in response to my question. To quote the relevant text above, you are the only one here who appears to not understand how gravity works. I suggest you return your degrees and go back to high school and learn the basics.

Apparently you missed the dictionary definition of unweighting which describes the reducing of the force down without requiring the elimination of all force down. Anyhow, if you have a better term to use let's hear it.

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

In the history of cycling I am only aware of three studies that have demonstrated cycling efficiency improvements in trained cyclists.

A couple of slides from a presentation I gave for USA Cycling a few years ago. I'm sure that there are more studies now (although obviously not all of these utilized trained cyclists, nor did they necessarily show ongoing improvement year-over-year...just making the point that the notion that cycling efficiency is immutable is questionable at best).

P.S. The earliest study that I have been able to locate that demonstrates an improvement in cycling efficiency with training dates from the 1930s.

That is why I specified cycling efficiency improvements in trained cyclists. We would expect training effect efficiency improvements as muscles adapted to exercise and became more efficient. Do you have any studies that show efficiency improvement that can't be accounted for by muscle adaptation? As I said, Lutrell, Coyle (Armstrong), and the OP (Weitzel) are about the only three I can think of. I think it is clear that improving efficiency, even a little bit, in TRAINED cyclists is not easy. When we see examples of it we ought to try to understand what is going on so, perhaps, the method could be applied to everyone. Instead, it seems, many of you would prefer to ignore or deny the possibility as thinking about how it might happen is too hard (or embarrassing if the answer is it might be related to technique). Surely, you have to admit, that Weitzel demonstrates, without a doubt, that technique can play a role in efficiency.

 

[JamesCun]

Re: Re:

Unweighting doesn't mean pulling up with force.

Frank, thanks for the BS condescending crap you wrote in response to my question. To quote the relevant text above, you are the only one here who appears to not understand how gravity works. I suggest you return your degrees and go back to high school and learn the basics.

Apparently you missed the dictionary definition of unweighting which describes the reducing of the force down without requiring the elimination of all force down. Anyhow, if you have a better term to use let's hear it.

I realize that you are purposefully dense, but let's get serious here. You said unweighting doesn't mean pulling up (quoted above). You are the one who doesn't understand basic concepts. Don't deflect the questions. You spin such webs that you get tangled all the time.

 

[CoachFergie]

Performance artist gotta perform!

 

[FrankDay]

Re: Re:

Unweighting doesn't mean pulling up with force.

Frank, thanks for the BS condescending crap you wrote in response to my question. To quote the relevant text above, you are the only one here who appears to not understand how gravity works. I suggest you return your degrees and go back to high school and learn the basics.

Apparently you missed the dictionary definition of unweighting which describes the reducing of the force down without requiring the elimination of all force down. Anyhow, if you have a better term to use let's hear it.

I realize that you are purposefully dense, but let's get serious here. You said unweighting doesn't mean pulling up (quoted above). You are the one who doesn't understand basic concepts. Don't deflect the questions. You spin such webs that you get tangled all the time.

Huh? I said unweighting doesn't involve pulling up WITH FORCE (on the pedals was implied). One must pull up with the muscles to reduce the downward force on the pedals on the backstroke that would normally be present if no muscle activity was involved. I am calling this action unweighting. If you have a better term let's hear it. If one unweights enough one can completely unload the pedal and actually apply a positive force to the pedal to drive the bicycle.

 

[FrankDay]

Re:

Performance artist gotta perform!

Enjoy! LOL

BTW Fergie, you might be interested to know that we got an inquiry today from the British Cycling Team (actually the EIS but they mentioned cycling) about doing a study. That is all I know. Should make for another interesting thread in a year or two should it go forward and the results made available to us all. Brace yourself everyone.

 

[JamesCun]

Re: Re:

Unweighting doesn't mean pulling up with force.

Frank, thanks for the BS condescending crap you wrote in response to my question. To quote the relevant text above, you are the only one here who appears to not understand how gravity works. I suggest you return your degrees and go back to high school and learn the basics.

Apparently you missed the dictionary definition of unweighting which describes the reducing of the force down without requiring the elimination of all force down. Anyhow, if you have a better term to use let's hear it.

I realize that you are purposefully dense, but let's get serious here. You said unweighting doesn't mean pulling up (quoted above). You are the one who doesn't understand basic concepts. Don't deflect the questions. You spin such webs that you get tangled all the time.

Huh? I said unweighting doesn't involve pulling up WITH FORCE (on the pedals was implied). One must pull up with the muscles to reduce the downward force on the pedals on the backstroke that would normally be present if no muscle activity was involved. I am calling this action unweighting. If you have a better term let's hear it. If one unweights enough one can completely unload the pedal and actually apply a positive force to the pedal to drive the bicycle.

Nice try frank. Constantly change your story as you try to wind your way through your numerous tales.

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

In the history of cycling I am only aware of three studies that have demonstrated cycling efficiency improvements in trained cyclists.

A couple of slides from a presentation I gave for USA Cycling a few years ago. I'm sure that there are more studies now (although obviously not all of these utilized trained cyclists, nor did they necessarily show ongoing improvement year-over-year...just making the point that the notion that cycling efficiency is immutable is questionable at best).

P.S. The earliest study that I have been able to locate that demonstrates an improvement in cycling efficiency with training dates from the 1930s.

Dr. Coggan, I did a little search to see if I could find some of these studies and I ran across your "slideshare". Perhaps you could tell me why for slide 22 you say "Evidence that increasing mechanical effectiveness does not improve cycling efficiency • Longitudinal (interventional) observations – Removing toe-clips and cleats does not reduce efficiency (Coyle et al. J Appl Physiol 1988; 64:2622-2630, Ostler et al. J Sports Sci 2008; 26:47-55) – Training using uncoupled cranks does not improve efficiency (Bohm et al. Eur J Appl Physiol 2008; 103:225-232, Williams et al. Int J Sports Physiol Perform 2009; 4:18-28) – Acutely altering pedal stroke to be “rounder” reduces efficiency (Korff et al. Med Sci Sports Exerc 2007; 39:991-995) " Is there a reason you mentioned Bohm and not Lutrell? Bohm gave you the results you were hoping for, that fits your understanding? Wouldn't it have been more educational to mention there are conflicting results regarding uncoupled cranks rather than choose the studies that fit your bias?

 

[CoachFergie]

Ha ha good one Frank, ignore the commentary from PhitBoy on the very poorly performed Luttrell study.

 

[PhitBoy]

Re: New study shows leg flexion less efficient than extensio

technique can play a role in efficiency.

Exactly! In fact, that is the topic of this entire thread. When people use a technique with lots of pulling up they become less efficient. A+

 

[FrankDay]

Re:

Ha ha good one Frank, ignore the commentary from PhitBoy on the very poorly performed Luttrell study.

Huh? Exactly what did I ignore?

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

technique can play a role in efficiency.

Exactly! In fact, that is the topic of this entire thread. When people use a technique with lots of pulling up they become less efficient. A+

Not quite. The original intent of the OP was to put down uncoupled pedaling. Of course, what anyone has learned from a close reading of this thread is that neither condition of this study replicates uncoupled pedaling. Further, I think we can take from this study that pushing down harder than necessary is also not very good (18.6% is a pretty awful efficiency), just not as bad as pulling up too hard.

As I said, this study is great for demonstrating that pedaling technique has an effect on efficiency. Those that say it doesn't simply are not paying attention to what is out there. The problem is nothing more can be learned from it. There are only two data points and two methods of pedaling studied. If there were 3 points would we see a straight line or a curvilinear relationship? What technique results in the best efficiency? A serious researcher should be looking for the variables that can be changed that affect this important parameter.

 

[acoggan]

Re: New study shows leg flexion less efficient than extensio

Do you have any studies that show efficiency improvement that can't be accounted for by muscle adaptation?

None of which I am aware. IOW, the available evidence points towards biochemical, not biomechanical, changes as being responsible for training-induced improvements in efficiency.

(BTW, note that the last 4 longitudinal studies were of trained cyclists.)