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#91 |
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Registered User
Join Date: Jun 2004
Location: Jyvaskyla, Finland
Posts: 665
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Beerco said: Where has this been shown?
Why in the only good study done of course.. I'll leave you to look it up. The cyclist wasn't just elite either... but all the others pulled up with no positive torque..ie, just enough to get the leg out of the way. When you're next to Frankie Andreu and hear the wzhhh wzhhh wzhhh with every down stroke, you know who's stomping and who's spinning. The stronger the rider, the more obvious the sound of their stomping is. Indeed that sound should correspond to the feet being at 3 o'clock and 9 o'clock. Just as shown in that study. However, one can't tell how much of that whz is from pulling up... the trailing foot is also at the best position to apply power at 9 o'clock where Ftan is maximal. One really needs force plate measurements to get the details, as was done in that study. I would be more interested in the results of such a test done on sprinters going over 1800 w. |
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#92 | |
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Registered User
Join Date: Nov 2003
Posts: 575
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Quote:
I expressed myself poorly. What I meant to say is that the goal is to achieve maximum sustainable power by whatever means is possible. I think you're picking up on it now though with the total energy thought. It is pretty well known in the physiology community (see the Coyle study) that peak torque in the pedal stroke is slightly more than double that of the average torque. So, for a given power output, more than 90% of the work is done between 1 and 5:00 in the pedal stroke. For a given power level, to apply force evenly you'd have to reduce peak torque by 1/2 and increase the torque everywhere else by up to 10 times! If you could increase the torque everywhere else to the same as peak, you'd see power more than double. But, it's not muscular force that's limiting your power production, it's oxygen delivery and utilization. It has been shown that by using a single leg, a test subject can sustain exercise at greater than 1/2 of VO2max (the upper limit for oxygen consumption). Think about what this means. This means that Leg 1+ Leg2= VO2max (ideally) but a single leg can consume more than 1/2 VO2max or...that Oxygen delivery is the issue, not how many muscles are using it. Also remember that your body can direct blood where it's required. Do you suppose there are any losses from trying to shuttle blood between a bunch of dinky little muscles like the hip flexor and the glute/quad as opposed to trying to feed just the glute/quad? I've said this in another post. The human body is not an electric motor and there's no reason to try and make it perform like one. It is much closer to a two cylinder IC engine. Two cylider engines have two big torque peaks as each cylinder fire and you know what, they work pretty darn well. |
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#93 | |
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Registered User
Join Date: Nov 2003
Posts: 575
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Quote:
That study shows that one or two elite cyclist barely pull and push the pedals at around 6:00 & 12:00. It also clearly shows that at 9:00, even the elites who are lifting are doing so at a torque less than 1/10th that of the down stroke. One could argue that the sub-elites lift to make up for a weaker down stroke, but I haven't heard anyone argue that...yet ![]() |
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#94 |
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Registered User
Join Date: Jul 2003
Location: dublin ireland
Posts: 383
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[QUOTE=beerco]
For a given power level, to apply force evenly you'd have to reduce peak torque by 1/2 and increase the torque everywhere else by up to 10 times! If you could increase the torque everywhere else to the same as peak, you'd see power more than double. But, it's not muscular force that's limiting your power production, it's oxygen delivery and utilization. That's true it's not muscular force that's preventing you from increasing torque everywhere else to the same as peak, it's not knowing what muscles to use and how to get most benefit from them, especially the arms and hips. |
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#95 |
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Registered User
Join Date: Dec 2004
Location: PHX, AZ
Posts: 93
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I think a pertinent point that beerco has made is that the pulling can't really contribute anything. I tried to make the point but failed. If you are generating suffucuent diwnward force then there is noithing for the "pulling" leg to pull. If you are not strong enough or are in the too alrge a gear then there is. THat was an observation I made back in my little experiment and was the only time I was able to measure or feel any tension that benefited from pulling up. I do know that in my case as I've gotten stronger and pushed down harder the only thing that I do is cler the leg quicker for the next push down and my power-tap and results keep saying that it's working ahead of my older smoother pedaling style.
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#96 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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As was said earlier smoothly is not evenly.
The upstroke can produce significant ammounts of force if the rider has trained their upstroke. Can someone show me the Coyle study? |
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#97 | ||
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Registered User
Join Date: Nov 2003
Posts: 575
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Quote:
No, it can't. (key being signifiCAN'T) Quote:
Gladly: http://www.midweekclub.com/articles/coyle91.pdf |
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#98 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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Why can't it?
I spent 3 months training training twice a week to improve my max power output via upstroke work. The hill is 5min walk from my house and I was climbing at 40rpm in a 39*15 on the first week. I moved up a cog every 2 weeks and now climb the same hill at 40 rpm in a 53*12. That's a massive improvement in max power output (not after sustainable just power for surges). |
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#99 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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The Coyle test is flawed because he studied cyclists who had trained for downstroke work. To measure the possible power from the upstroke he should at least test on a subject who has trained with upstroke work.
It shows that "elite' riders push more on the downstroke. I don't think this suprises anyone as more pressure results in more force. It's a bit like comparing a 2 litre car to a 5 litre and concluding that engines with a higher capacity create more power. Both groups created significantly more pressure on the downstroke, but the elite riders created more. Group 2 used a slightly larger pedal angle (pedal up) which suits downstroke work. This is common for track riders and is the only peice of useful information for this thread in the study. Coyle 1991 Begining on page 6. |
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#100 | |
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Registered User
Join Date: Nov 2003
Posts: 575
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Quote:
It can't because those muscles are just too small. I'm sure you got more fit and faster, it just isn't because you worked on your upstroke. I thought of an interesting experiment - go buy yourself some powercranks and a power tap. Now go for a ride except never pedal with a downstroke. i.e. pull up with one leg then return that leg backward to 6:00 and start again. Get back to us on how little power you make on the upstroke. p.s. do you find yourself pedaling at 40rpm often during your rides? |
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#101 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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When the bunch is doing 60kph down the back straight I do.
There was no fitness work involved in this power training (it was low heart rate work). I was averaging 91% of my max HR in time trials before and after this training. The glutes are very large muscles. If you hadn't noticed they keep you verticle all day and are very strong. Last edited by Brizza : 31-05.-2005 at 11:52 AM. |
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#102 | |
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Registered User
Join Date: Jun 2004
Location: east coast australia
Posts: 1,309
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Quote:
I'm not sure which part of my post you are referring to but I'm sure if you are a coach you have seen studies to show that concentrating on pulling up reduces power overall. And from experience you can see that good cyclists pedal smoothly. That doesn't mean they can't develop more power in one part of the stroke than another. If you read studies you would know that they do. I didn't ever claim otherwise. So what part of my post is contrary to existing evidence? It sounds like you haven't read it properly. |
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#103 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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Who would focus on the upstroke and ignore the downstroke?
While I've had a massive jump in power from my upstroke, I still train with platform pedals and sandshoes to work on my downstroke. |
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#104 | |
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Registered User
Join Date: Jul 2003
Location: dublin ireland
Posts: 383
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Quote:
The question arises, when do you stop focusing on your upstroke. As JERRYZ stated, his increase in power seems to come from the earlier start to the downstroke which in a way is the same objective as the rotorcrank idea. By focusing on pulling up, you are delaying the start of your downstroke and this is one of the ways that pulling up reduces overall power. The advantage that you are getting from pulling up is the result of unweighing and if you concentrated on the correct unweighting technique and an earlier start to your downstroke, you would see an even greater increase in power. |
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#105 |
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Registered User
Join Date: Jun 2003
Location: Newcastle, Australia
Posts: 334
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I didn't see you on the side of the road watching to see if I was or wasn't pushing down yesterday.
While training you can only specialise in one but why can't you use both when racing? Just because you can't do both doesn't mean others can't. |
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