Is Height A Factor ?

[old] hwt · Post by **[old] hwt** » January 26th, 2005, 10:34 pm

Whoever crosses the finish line first wins the race.

[old] GeorgeD · Post by **[old] GeorgeD** » January 26th, 2005, 11:33 pm

Paul (who has I think tried to explain this to me before) or anyone else - can you please explain again in english how the C2 calculates the pace I am rowing at. What are the variables that I can influence and their effect on pace - rate, drag, stroke length??? Obviously it is the marrying / combination of these factors with my physiological make up that will result in optimum performance. tks George

[old] PaulS · Post by **[old] PaulS** » January 27th, 2005, 1:32 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Jan 26 2005, 06:24 PM)</div></td></tr><tr><td class='quote'>PaulS, Thanks for clearing that up. As regards Torque, this jpg shows torque and watts having a direct relationship, i.e. 19:1000 and 9.5:500 etc. <a href='http://www.ps-sport.net/images/forceplot.jpg' target='_blank'>http://www.ps-sport.net/images/forceplot.jpg</a> Is this not the case then? </td></tr></table> Well John, that's not what it shows at all. I can recall you had a problem with understanding a graphical representation previously and tried to relate the Left and right Y axis values in the same way. The Watts scale is only a reference for the Watts plot, notice they are both Red. The Torque scale is for the torque plot, Navy Blue. The TorqueJoule is the Royal Blue plot. The Max value for all of these can be set independently to place the plot as desired. The Watts plot is much like a sine wave, though only the portion during the drive is being shown. That should clear it up, unless you truly do not want to understand. I also have a hint for you, listen the first time I answer the question, and if you think my answer was not right, keep thinking until you understand how it is right, it will save a lot of time.

[old] John Rupp · Post by **[old] John Rupp** » January 27th, 2005, 2:46 am

Paul, You are wrong again. I remember you not being able to add 5 + 5, but have absolutely no problem at all with you not being able to label your chart. Anyway, thanks ? for clearing up the confusion it created.

[old] PaulS · Post by **[old] PaulS** » January 27th, 2005, 10:21 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Jan 26 2005, 10:46 PM)</div></td></tr><tr><td class='quote'>Paul, You are wrong again. </td></tr></table> Ah, back to normal. For a moment there I thought your meds had begun to work. Let your witchdoctor know the dose is still too low.

[old] PaulH · Post by **[old] PaulH** » January 27th, 2005, 10:27 am

That's OK John, you don't have to read anything I write. If you had you might know that I don't advocate people do anything in particular, with one exception - I think people should try to row at lower drag factors, at least to try it, because it's easier on the back. So I'm not trying to force anybody to do anything (such as this 20spm thing - I've never recommended it or even done it). If you wanted to apologize for lying about what I said that would be fine, but it's your decision. No, the reason I'm posting here is not to recommend that people do something, it's merely to point out that when you say that height isn't a factor you're wrong, and your reasoning is wrong. As to whether I row anything - I don't put my times on the forum because it's not a standard thing to do, and it's extra work that I would almost certainly forget to update. But every workout is posted on the C2 ranking site, and my best times are on the Nonathlon site. I also row and cox for the Minneapolis Rowing Club, and this year have the dubious honor of being one of two 'Sport Program' captains. None of that should be construed as meaning that I'm any good of course, because I'm not - I'd be very happy if I could match any one of your times. Btw - the discussion you just had with PaulS on the nature of the graph. You're wrong. The interpretation of a graph can sometimes be an art, but the reading of one (what scale goes with what line etc.) isn't - it's a precise and definable thing, and yet you can't even see you're wrong on that. Cheers, Paul

[old] PaulS · Post by **[old] PaulS** » January 27th, 2005, 10:37 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Jan 26 2005, 06:26 PM)</div></td></tr><tr><td class='quote'>So would you say, then, that 8 mps is good for teams like Ebbesen's, having a lighter and faster stroke, but that 10 mps is better for teams that have a lower rate but drive harder. </td></tr></table> Only if you have the energy to spare on inefficiency, seems to work for EE's boat, just not the rest of the Danish Team. Otherwise, the ratio established by 10mps is better, from an efficiency POV. I can't recall saying that sacrificing efficiency for raw performance is a bad thing, it may just allow you to win the race, but not if your competition is equally conditioned and more efficient. i.e. 2004 Olympics M8+, The USA rowed a very good first 1750, the NED boat was too reserved and when they fianlly attacked it was too late to win. The USA went into a sprint in response to the attack, and though they had a speed increase, the Dutch were closing very rapidly. All these guys are in great shape but the Dutch showed much greater efficiency coming into the finish. Hopefully the USA takes away the importance of the first 1750m in being able to survive that final bit, otherwise it's going to be another 40 years to the next gold.

[old] John Rupp · Post by **[old] John Rupp** » January 28th, 2005, 7:51 pm

PaulH, I simply quoted you and said it was nice you agreed. If you didn't mean to say what you did or to have it come across as it did then you are welcome to change what you said. On the other hand, for someone who doesn't row much you make a lot of assumptions and assertions. Try going out and rowing a couple of hours every day for 3 or 4 years. While you're doing this, row at high drag factors, low drag factors, 7.1, 8.0, 8.7, 9.1, 10.0, 11, and 12.5 meters per stroke, 10, 12, 15, 20-30, 30-40, and 40-50 strokes per minute. Include these in your training, as it will become, in a multitude of various ways. That's just for a start. When you have done this you can come back and ask me some questions and I will be happy to assist you. But in the meantime don't pretend that you know anything about the things that I say, and don't ever tell me that I'm wrong, because you don't have a clue. Cheers. Have a nice day.

[old] PaulH · Post by **[old] PaulH** » January 28th, 2005, 8:28 pm

Find anywhere that I've tried to force people to row at 20spm, or do anything else on this forum. The fact is that I don't tell people what to do in rowing unless I'm coxing, when that's part of my responsibility, and you claiming that I do is a lie. As I said, you don't have to apologize for lying about me, that's your choice. As to not rowing much, compared to some that's very true. I've only been rowing for a couple of years, and erging for 6. So I'd need your help to tell me how to go out and row at high drag factors, low drag factors, and at specified meters per second. If it helps you to tailor the advice I normally row two seat in an eight, and two or three seat in a quad. The eight has a coxbox, but otherwise no speedcoaches or other devices available. I'd also love to hear what you row. And about saying you're wrong - if you're able to demonstrate that you're right I'll apologize fully. That should be obvious by the fact that as soon as it was brought to my attention, I was the one who posted the information about the Italian race that measured the winner by W/kg - I'm always prepared to admit when I get something wrong. But until then you're wrong both as a matter of fact and of logic. You got one thing almost right - there are times when I don't really know what you're talking about, but that's to do with the foundationless ideas you come up with rather than the inadequacy of my intellect. In those cases I'd say that neither of us knows what you're talking about. Cheers, Paul

[old] John Rupp · Post by **[old] John Rupp** » January 28th, 2005, 9:18 pm

PaulH, Considering lies, damned lies, and statistics, which one are you? Your whole message is aggressive and pushing something that you know nothing about. #1- You said I lied by saying you force people to row at 20spm. #2- You said I lied by saying there was a competition based on watts/kilogram. I have said neither of those things yet you have kept asserting or suggesting that I did. You called me names but you are the one who keeps falsely accusing. Ah what a vicious cycle you are in. I wished you a nice day but apparently you don't wish to have one. Que sera sera.

[old] Bill · Post by **[old] Bill** » January 29th, 2005, 12:58 am

Hey PaulS, I need some help with the rhetorical question you asked about power please - excuse the mixed units - they dont really affect the logic. assume lift the weight 1metre 200times x 50lbs x 1metre = 10,000lbmetres 100times x 100lbs x 1metre = 10,000lbmetres so if both athletes do this lifting in the same time (assume 10 minutes for simplicity) havent they got the same power rating ? ie 10,000lbmetres/10minutes = 1000lbmetres/minute for each athlete isnt this a bit like two ergers doing a pace of 2:00 using 25spm and 20spm ? one athlete certainly has to put more effort into a single stroke but both are doing work at the same rate - (power) measured in watts on the erg ? Maybe I need to revise my physics a bit more to better understand what you meant with the question. I will apply to the International Standards Committee to have the unit of a lbmetre/minute designated as a new unit called the billshovel. And I still havent cracked the big 7:00 Bill

[old] jamesg · Post by **[old] jamesg** » January 29th, 2005, 4:24 am

GeorgeD You ask how the C2 calculates pace. I think it works like this, measuring the work we put in, and then calculating the "pace": Engineering: there's a sensor near the flywheel that produces impulses, I believe three for every turn of the fly-wheel; Electronics: counters are used to measure the time between successive impulses, and so detect the fastest and the slowest flywheel speeds, and also to measure the times between these peaks. So we know the highest flywheel speed (at release) the lowest (at the catch) and the time between these two - which is the recovery time. Physics: if we know the inertia of the flywheel, then using those two speeds, we can calculate the energy lost by the flywheel as it slows down during the recovery. As we know both the recovery and the pull time (catch to release), we can extrapolate this energy loss, during the recovery, to the entire stroke length, to include the pull time too. This gives us the amount of energy lost by the flywheel during the entire stroke, which by definition = the work we put in. Then we divide the work done by the total stroke time, and the result is power, in Watts. The PM2 shows this at the end of each stroke, when it can at last do all the sums. In actual fact, things may well be done differently, but this is a reasonable description of the physics. The basic point is that we can see the flywheel slow down during the recovery, when there is no power input, and so calculate the power loss. Only possible because rowing is discontinuous. In any case it's a very nice piece of engineering, just a sensor and a few timers, with some nifty software of course. The fictitious "pace" is calculated from this Power using a cube function, because the drag on a hull is roughly proportionate to the square of the speed, so long as the bow wave is not significant.

[old] PaulH · Post by **[old] PaulH** » January 29th, 2005, 9:54 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Jan 26 2005, 06:35 PM)</div></td></tr><tr><td class='quote'>Like I have said before and said on the old forum too, if you want to row at 20 spm then have at it. That doesn't bother me, at all. You see I have a different outlook than you do. I have no intention to try and "force" anyone to do anything, as you seem intent on doing. </td></tr></table> <table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(John Rupp @ Jan 28 2005, 08:18 PM)</div></td></tr><tr><td class='quote'>#1- You said I lied by saying you force people to row at 20spm. #2- You said I lied by saying there was a competition based on watts/kilogram. I have said neither of those things yet you have kept asserting or suggesting that I did. You called me names but you are the one who keeps falsely accusing. Ah what a vicious cycle you are in. </td></tr></table> So assertion number one is wrong - I don't seem intent on forcing anyone to do anything, least of all row at a pace I've never knowingly rowed myself. You said I did, and then lied about that too! Now find me a similar quote that shows how I made the second assertion - I didn't, I suggest that for W/Kg tobe 'the way' that performance is measured, as you claim, that there should be more global recognition of that fact. I challenged you to find one, and thanks to Ralph one has turned up. One. So please, quote anything where I falsely accused you and I will publicly apologize. I'd like to think I could expect the same from you. Cheers, Paul

[old] jamesg · Post by **[old] jamesg** » January 29th, 2005, 2:01 pm

I took part in that 500m race, where the results were on a W/kg basis. There were only a few of us, about 50 people in total if I remember right. I plotted the W/kg ratio against weight and also against age. There was no correlation between weight and the ratio, and very little between age and the ratio, between 20 and 50. I didn't have any height data so couldn't calculate BMIs to see if there's an ideal value for ergers... The lack of correlation could mean this rato is a good overall measure of a mix of technique, fitness, general athletic ability for all weights and to some extent ages. If linked to 500m only, it might seem to reward brute force over endurance. However the best result we saw was by a lightweight, higher than 7. Any other distance can be used of course. Certainly I can't see how anyone with no fitness, lousy technique and no athletic ability could get a high ratio, whether or not there's global recognition... I'd have no objection to putting my weight in the rankings and have it calculate this ratio, however useless and narcissistic it is. After all the machine serves to get us fit and that is what it does. Why shouldn't we look for an absolute fitness index that's independent of weight etc? Maybe there's a better one around, let's hear about it.

[old] John Rupp · Post by **[old] John Rupp** » January 29th, 2005, 4:48 pm

James, Thanks for your well rounded viewpoints. I agree. PaulH, You keep contradicting yourself. All anyone has to do is read your last message or any of your others to see what a vindictive fool you are making out of yourself. And I have no reason to apologize for your carelessness. Geesh what a control freak.

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Is Height A Factor ?

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