Pulling up on the pedals - An Experiment
martinheadon
Posts: 12
I noticed recently that I seemed to increase my power (measured by Stages crankarm) when I pulled up on my pedals. But it didn't necessarily mean I was going any faster. So I did a little experiment. First of all, I did 30 seconds pedalling at 95rpm, only pushing down in the pedal stroke.
My rpm is 95, my speed is 19.6mph, and my power is 246. Then I did another 30 seconds, but this time pulling up on the pedals.
Same rpm and average speed, but this time my power is significantly higher - 275.
So, does this mean that I should start concentrating on the downstroke only, for maximum efficiency? There does seem to be a body of opinion that pulling up / pedalling in circles is no longer the way to go. Would it be a good idea to fit flat pedals to my turbo trainer bike, to train my legs not to push up?
And if I measured my FTP as 266 while pulling up on the pedals, is that possibly an overestimation of my actual ability? Should I test again while just pushing down on the pedals and see what I can do?
My rpm is 95, my speed is 19.6mph, and my power is 246. Then I did another 30 seconds, but this time pulling up on the pedals.
Same rpm and average speed, but this time my power is significantly higher - 275.
So, does this mean that I should start concentrating on the downstroke only, for maximum efficiency? There does seem to be a body of opinion that pulling up / pedalling in circles is no longer the way to go. Would it be a good idea to fit flat pedals to my turbo trainer bike, to train my legs not to push up?
And if I measured my FTP as 266 while pulling up on the pedals, is that possibly an overestimation of my actual ability? Should I test again while just pushing down on the pedals and see what I can do?
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Comments
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Someone pleaae correct me if im wrong but I thought you are supposed to get the foot through the upstroke as quick as possible and unweighted so you dont lose the momentum of the power you put through the downstroke?
That would explain why more power was needed in the second test.0 -
http://www.cyclingweekly.co.uk/fitness/training/how-to-pedal-efficiently-173185
http://www.bikejames.com/strength/why-pulling-up-doesnt-add-to-your-pedal-stroke-power/
http://roadcyclinguk.com/riding/bike-fitting-the-myth-of-the-upstroke.html#lQyMIwXxkk8i7LSI.97
http://www.telegraph.co.uk/men/active/recreational-cycling/10840824/How-to-cycle-with-the-technique-of-a-pro.html
https://books.google.co.uk/books?id=wMgEBAAAQBAJ&pg=PA174&lpg=PA174&dq=pulling+up+on+pedals+efficiency+phil+burt&source=bl&ots=fFUCFrVAk-&sig=cd3822vq9DOSpgQsw7Oq4bLMJe0&hl=en&sa=X&ved=0CDwQ6AEwBGoVChMIve2A_cHYyAIVhF0UCh08bwKd#v=onepage&q=pulling%20up%20on%20pedals%20efficiency%20phil%20burt&f=false0 -
As speed is directly proportional to rpm, then of course you will be going the same speed at the same rpm (and probably the same power). I would suggest you changing the style of pedalling is causing an error in measurement. You'd probably have more success using a dual sided power meter or a powertap hub, but it would tell you that you are doing the same rpm and speed for the same power no matter what your pedalling technique. Your experiment is flawed, you'd need to look at your bodies reaction to either to find out which is more efficient, If any...0
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I think you just discovered another limitation of a single sided power meter.....
Id suggest that what you're seeing is a large error in the power number as you favour your left leg when you starting messing around with your pedal stroke.More problems but still living....0 -
I noticed recently that I seemed to increase my power (measured by Stages crankarm) when I pulled up on my pedals. But it didn't necessarily mean I was going any faster. So I did a little experiment. First of all, I did 30 seconds pedalling at 95rpm, only pushing down in the pedal stroke.
My rpm is 95, my speed is 19.6mph, and my power is 246. Then I did another 30 seconds, but this time pulling up on the pedals.
Same rpm and average speed, but this time my power is significantly higher - 275.
So, does this mean that I should start concentrating on the downstroke only, for maximum efficiency? There does seem to be a body of opinion that pulling up / pedalling in circles is no longer the way to go. Would it be a good idea to fit flat pedals to my turbo trainer bike, to train my legs not to push up?
And if I measured my FTP as 266 while pulling up on the pedals, is that possibly an overestimation of my actual ability? Should I test again while just pushing down on the pedals and see what I can do?
"STRETCHY" is correct.
Presentation Abstract
Session: B-41-Sports Equipment
Wednesday, May 27, 2015, 1:00 PM - 6:00 PM
Presentation: 914 - A Counterweight Improves Efficiency for an Amputee Cyclist
Location: Exhibit Hall F, Poster Board: 310
Pres. Time: Wednesday, May 27, 2015, 2:00 PM - 3:30 PM
Category: 0402. Biomechanics and Neural Control of Movement - sport biomechanics
Keywords: cycling; efficiency; amputee
Author(s): Brett A. Weitzel1, Daniel S. Nelson1, Steven J. Elmer2, Jim C. Martin, FACSM1. 1The University of Utah, Salt Lake City, UT. 2Michigan Technological University, Houghton, MI. (Sponsor: Jim C. Martin, FACSM)
Abstract: Cycling technique is steeped in cultural lore. One deeply held belief is that pedaling techniques which increase the pulling action (muscular leg flexion) will improve efficiency. In contrast, research indicates that cycling efficiency is reduced when cyclists increase leg flexion power. These previous studies used acute interventions that may not have allowed sufficient time to adapt to and refine the technique. Single-leg amputee cyclists must produce substantial leg flexion power to lift the leg and thus have likely optimized the pulling action. The cyclist who volunteered for this investigation is a 4 time U.S. National Champion in road and track events who has performed single-leg cycling for 7 years. Thus, he should have a fully adapted and refined pulling technique. Purpose: To evaluate the effect of a counterweight system, which reduces the requirement for muscular leg flexion, on the metabolic cost and efficiency of a single-leg amputee cyclist. Methods: The cyclist performed two incremental cycling trials (100W + 35W/5min); one with and one without an 11.6kg counterweight on the unused crank. Expired gasses were measured and data from the last minute of each stage were used to calculate metabolic cost and efficiency. Differences in metabolic cost and efficiency for the four stages were evaluated using separate paired Student’s t tests. Results: Metabolic cost for the four incremental stages was reduced by 1.2±0.1kcal/min (p<0.001) and efficiency was increased from 16.8±2.0% to 18.6±1.8% (p<0.001) when cycling with the counterweight system. Conclusion: A counterweight system, which reduced the requirement for muscular leg flexion, decreased metabolic cost and increased efficiency even in this amputee single-leg cyclist who must pull up substantially during his normal cycling. The changes observed in this individual were similar to those observed during previous acute double- and single-leg interventions suggesting that previous results were not confounded by lack of practice. Rather, it appears that pulling up during cycling is inherently more metabolically costly and less efficient than pushing down. These data suggest that cyclists should not adopt pedaling techniques which increase the pulling action. Finally, a counterweight system may increase performance and enjoyment for amputee cyclists.
Disclosures: B.A. Weitzel: None.0 -
interesting experiment for sure but you have to conduct for longer and report back. First if you were cycling outside then conditions are too variable to draw conclusions about cadence and speed given variations in course, temp, air pressure, rolling surface and wind. If you are riding inside eg on the turbo then this is more promising but 30secs N of 1 study is too haphazard. If you repeated 5-10 times and got the same result then at least we would have more confidence in the data (no criticism of you, just looking at this as a scientific experiment).
So lets assume the finding is consistent and reliable. If you discount the speed and cadence then you have discovered that my pulling on the upstroke (or concentrating more on this) does help your power approx 12% which is a very useful gain under similar conditions. On the other hand if you don't discount the speed and cadence then you have discovered that my pulling on the upstroke (or concentrating more on this) doesn't help your output (speed) which was the same despite giving 12% more power which is disappointing. However in both cases it is v odd to generate more power and yet go at the same speed. The only way to explain this is if conditions changed between tests 1 and 2. Which effectively tells us the experiment, although interesting, went wrong somewhere because it is impossible for conditions to stay exactly the same and for more power input to NOT be reflected in some kind of improvement in output.
My conclusion. Very interesting, but please repeat a few times, keep conditions controlled and ideally indoors and report back!0 -
Were you recording HR too for these tests ?0
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It starts out with promise, using one pedalling dynamics study to refute one myth wrt pedalling "technique", then goes off the rails by launching straight into recommending other belief-based pedalling techniques.0 -
Do you even bother to read this stuff before posting? That's the same article you posted earlier.0 -
Do you even bother to read this stuff before posting? That's the same article you posted earlier.
mmmm one post is for part ONE and the other is part TWO :oops:0 -
If only they had put a link to part TWO at the end of part ONE!0
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If only they had put a link to part TWO at the end of part ONE!
Great idea
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Still mixes in belief based statements.0
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Do you even bother to read this stuff before posting? That's the same article you posted earlier.
whoops, do you even bother to read this stuff before posting?
Keep up - we've already covered that.0
