10mps: Race Pace, Stroking Power, And Ratio

[[old] PaulS]

<!--QuoteBegin-ranger+Dec 27 2005, 10:17 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(ranger @ Dec 27 2005, 10:17 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->1:50 @ 18 = 877/0.8 = 1096 Drive Joules<br />1:35 @ 32 = 765/0.6 = 1275 Drive Joules </td></tr></table><br /><br />My interest is in 1:36 @ 32 spm, not 1:35. How do the numbers come out then? <br /><br />You also didn't answer my initial question. How does the stroking power rowing at 20 spm and 12.5 SPI relate to the stroking power of rowing at 12.5 SPI and 30 spm? <br /><br />And what _does_ happen to this comparison of the needed stroking powers if you raise the drag for the 30 spm rowing from 105 df. to 122 df.?<br /><br />ranger <br /> </td></tr></table><br /><br />Slicing it finer is not going to help you.<br />1:50 @ 18 = 877/0.8 = 1096 Drive Joules<br />1:35 @ 32 = 765/0.6 = 1275 Drive Joules<br />1:36 @ 32 = 742.5/0.6 = 1237 Drive Joules<br /><br />SPI 12.5: Both require 750 joules input (obviously), but the drive times make the difference.<br />SR = 20 = 1:51.8 = 937 Drive Joules<br />SR = 30 = 1:37.7 = 1250 Drive Joules<br /><br />You'd need to spend some time with ErgMonitor to determine what happens when you raise the DF and keep the rate constant. One thing that does change is the ratio, another would be peak force requirement. It's a trade off, and may well be too severe to take advantage of in a 2k, but perhaps a very short piece would be okay.<br /><br />The transition to a longer drive time, even if it requires less peak force, takes some time. (Rowers have to do this after winter Erg training every year, and it's not very pleasant.) The converse is true when coming back to the Erg, we like the higher Drag, but if we stuck with that we would be too slow at the catch to do what we need in a boat.

[[old] John Rupp]

<!--QuoteBegin-PaulS+Dec 27 2005, 11:37 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulS @ Dec 27 2005, 11:37 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->You'd need to spend some time with ErgMonitor to determine what happens when you raise the DF and keep the rate constant.  [right] </td></tr></table><br /><br />Except all you'll find out is that EM is not accurate and, thus, gives you a bunch of gobblity gook numbers that don't mean anything.<br /><br />Kind of like the postings of PaulS.

[[old] PaulS]

<!--QuoteBegin-John Rupp+Dec 27 2005, 11:44 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(John Rupp @ Dec 27 2005, 11:44 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-PaulS+Dec 27 2005, 11:37 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulS @ Dec 27 2005, 11:37 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->You'd need to spend some time with ErgMonitor to determine what happens when you raise the DF and keep the rate constant.  [right] </td></tr></table><br /><br />Except all you'll find out is that EM is not accurate and, thus, gives you a bunch of gobblity gook numbers that don't mean anything.<br /><br />Kind of like the postings of PaulS. <br /> </td></tr></table><br /><br />Now there is the John that we know, nothing at all to offer. Well, except for a good laugh and proof that recommended dosages should not be altered.

[[old] DavidW]

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[[old] H_2O]

Ranger,<br /><br />The following workout suggested by Xeno might give you some clues to the deterioration of SPI under higher stroke rates. You do three times 7 minutes spm restricted at max pace with complete recovery<br />and stroke rates<br /><br />23, 25, 27 spm.<br /><br />(Xeno suggests 22, 24, 26 but that is a cadence I cannot easily hit).<br />This is what I typically see:<br /><br />23 spm (slightly more): 322 Watts (1:42.8)<br />25 spm: 335 Watts (1:41.4)<br />27 spm: 351 Watts (1:39.9)<br /><br />So it looks like for each additional stroke you can take off about 0.7 seconds on the splits.<br />That is certainly different from low ratings (18 spm) where you will take off 1.5 - 2 seconds for each additional stroke. <br /><br />Actually it looks like each additional stroke adds a constant increment in Watts which is a good way to look at it. This will make the splits decrease by diminishing increments and the SPI to deteriorate.<br />But I think that for the purpose of racing the SPI is not a significant variable, power output in watts is the significant variable.<br /><br />If the stroke rate goes higher we can expect the increase in Watts for each additional stroke to diminish since it is hard to keep up technique.<br /><br />This of course does not answer which stroke rate is the most efficient to achieve a given pace.<br />My own guess here is to trade rate for pace and rate 32 - 35 (34, 35 in the last 600m). The reason is that if we pull too hard fast twitch fibers will be recruited and these are big lactate producers.<br />I don't think that the increased number of reversions of motion at the end of the pull presents a problem since you can basically stop yourself from sliding backward with a powerful finish of the stroke (equal and opposite reaction) so there is no special effort in turning around.<br /><br />I don't think that shortening the recovery presents a problem either.<br />All that matters is to absorb the maximum amount of oxygen and rating higher you will breathe more often and thus ventilate more air through the lungs.<br /><br /><br />

[[old] H_2O]

<!--QuoteBegin-PaulS+Dec 27 2005, 02:37 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulS @ Dec 27 2005, 02:37 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><br />Slicing it finer is not going to help you.<br />1:50 @ 18 = 877/0.8 = 1096 Drive Joules<br />1:35 @ 32 = 765/0.6 = 1275 Drive Joules<br />1:36 @ 32 = 742.5/0.6 = 1237 Drive Joules<br /><br />SPI 12.5: Both require 750 joules input (obviously), but the drive times make the difference.<br />SR = 20 = 1:51.8 = 937 Drive Joules<br />SR = 30 = 1:37.7 = 1250 Drive Joules<br /><br /> </td></tr></table><br /><br />This analysis is not what we need.<br />We know that to go faster you need to put in more energy.<br /><br />The question must be asked as follows:<br /><br />Given a fixed pace (equivalently a fixed power output) is there an optimal stroke rate.<br />Here I would define an optimal stroke rate as one that has the least force during the drive<br />since this recruites the least number of fibers leading to minimal oxygen demand.<br /><br />Here we need to know the duration of the drive for each stroke rate.<br />I can develop an approximate formula for you under the assumption of linear change of the ratio of drive/recovery once I have the following parameters:<br /><br />At which spm is that ratio 1:2.<br />At which spm is the ratio 1:1<br /><br />I think the relevant 2K racing spms will be between these extremes.<br /><br />PaulS can you supply these spms?<br /><br /><br />

[[old] PaulS]

<!--QuoteBegin-H_2O+Dec 28 2005, 05:15 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(H_2O @ Dec 28 2005, 05:15 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-PaulS+Dec 27 2005, 02:37 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(PaulS @ Dec 27 2005, 02:37 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><br />Slicing it finer is not going to help you.<br />1:50 @ 18 = 877/0.8 = 1096 Drive Joules<br />1:35 @ 32 = 765/0.6 = 1275 Drive Joules<br />1:36 @ 32 = 742.5/0.6 = 1237 Drive Joules<br /><br />SPI 12.5: Both require 750 joules input (obviously), but the drive times make the difference.<br />SR = 20 = 1:51.8 = 937 Drive Joules<br />SR = 30 = 1:37.7 = 1250 Drive Joules<br /><br /> </td></tr></table><br /><br />This analysis is not what we need.<br />We know that to go faster you need to put in more energy.<br /><br />The question must be asked as follows:<br /><br />Given a fixed pace (equivalently a fixed power output) is there an optimal stroke rate.<br />Here I would define an optimal stroke rate as one that has the least force during the drive<br />since this recruites the least number of fibers leading to minimal oxygen demand.<br /><br />Here we need to know the duration of the drive for each stroke rate.<br />I can develop an approximate formula for you under the assumption of linear change of the ratio of drive/recovery once I have the following parameters:<br /><br />At which spm is that ratio 1:2.<br />At which spm is the ratio 1:1<br /><br />I think the relevant 2K racing spms will be between these extremes.<br /><br />PaulS can you supply these spms? <br /> </td></tr></table><br /><br />Do you mean "relevant 2k racing spm's"? Sure, 28-38.<br />ErgMonitor will report Stroke ratio for any stroke you take. <br /><br />If you mean spm's for the given ratios, no. (that's not possible to quantify accurately with the constraints supplied)<br />It is possible to row a SR=AnyRate at either a 1:2 or 1:1 ratio, and even have those produce the same pace.<br />Changing DF would change the Pace if the Dist/Stroke (DPS) and ratio were held constant.<br />For a Given DF and DPS the ratio stays the same regardless of pace.<br /><br />It would be possible to go on, but I think this is enough to understand why it's more complicated than simply rates and ratios.

[[old] ranger]

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->SR = 20 = 1:51.8 = 937 Drive Joules<br />SR = 30 = 1:37.7 = 1250 Drive Joules </td></tr></table><br /><br />Thanks!<br /><br />How many joules is 30 spm at 10.5 SPI?<br /><br />ranger

[[old] PaulS]

<!--QuoteBegin-ranger+Dec 29 2005, 01:35 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(ranger @ Dec 29 2005, 01:35 PM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->SR = 20 = 1:51.8 = 937 Drive Joules<br />SR = 30 = 1:37.7 = 1250 Drive Joules </td></tr></table><br /><br />Thanks!<br /><br />How many joules is 30 spm at 10.5 SPI?<br /><br />ranger <br /> </td></tr></table><br /><br />Do you mean "Drive Joules"? <br />Because Joules = watts * (60/SR)<br />SPI = Watts/SR <br />or <br />Watts = SR * SPI<br /><br />SR = 30, SPI = 10.5, Drive Joules = 1049 (w/0.6sec Drive time), Pace = 1:43.6<br /><br />What is this representing?

[[old] ranger]

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->SR = 30, SPI = 10.5, Drive Joules = 1049 (w/0.6sec Drive time), Pace = 1:43.6 </td></tr></table><br /><br />Ah. O.K. I get the joules business.<br /><br />So where do you get the drive time from?<br /><br />And how does drive time vary with drag? I am no longer rowing at 105 df. (setting 2). I am now rowing at 122 df. (setting 4).<br /><br />What is the drive time at 122 df., 1:44 @ 24 spm?<br /><br />This seems to be emerging as a new distance pace for me (e.g., 60min). This is pleasing. Again, 1:44 @ 24 spm is UT1 for a 6:16 2K.<br /><br />Do you have a list of various drive times at 12.5 SPI, 122 df., and a full spread of relevant rates (e.g., 16-44 spm)? If so, that might be useful to me.<br /><br />ranger

[[old] Mike Niezgoda]

<!--QuoteBegin-ranger+Dec 30 2005, 10:10 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(ranger @ Dec 30 2005, 10:10 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->SR = 30, SPI = 10.5, Drive Joules = 1049 (w/0.6sec Drive time), Pace = 1:43.6 </td></tr></table><br /><br />Ah. O.K. I get the joules business.<br /><br />So where do you get the drive time from?<br /><br />And how does drive time vary with drag? I am no longer rowing at 105 df. (setting 2). I am now rowing at 122 df. (setting 4).<br /><br />What is the drive time at 122 df., 1:44 @ 24 spm?<br /><br />This seems to be emerging as a new distance pace for me (e.g., 60min). This is pleasing. Again, 1:44 @ 24 spm is UT1 for a 6:16 2K.<br /><br />Do you have a list of various drive times at 12.5 SPI, 122 df., and a full spread of relevant rates (e.g., 16-44 spm)? If so, that might be useful to me.<br /><br />ranger <br /> </td></tr></table><br /><br /><br />Ranger,<br /><br />I am fairly certain that Paul is just assuming a drive time of 0.6 seconds. Drive Time is one of the "gobblity gook" metrics that ErgMonitor outputs.<br /><br />With a bit of time, I think I can put together a spreadsheet or a small program that allows you to enter the following metrics and calculate the missing metrics:<br /> - SPI<br /> - Stroke Rate<br /> - Stroke Count <br /> - Drag Factor<br /> - Drive : Recovery Ratio<br /> - Pace (seconds/500m)<br /> - Drive Length (cm)<br /> - Drive Time<br /> - Distance<br /> - Time for Distance<br /> - Drive Joules<br /><br />No promises on a time when I can get it done, but it is something I have been thinking about incorporating into the workout setup window in ErgMonitor.<br /> <br />- Mike

[[old] ranger]

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->With a bit of time, I think I can put together a spreadsheet or a small program that allows you to enter the following metrics and calculate the missing metrics:<br />- SPI<br />- Stroke Rate<br />- Stroke Count <br />- Drag Factor<br />- Drive : Recovery Ratio<br />- Pace (seconds/500m)<br />- Drive Length (cm)<br />- Drive Time<br />- Distance<br />- Time for Distance<br />- Drive Joules </td></tr></table><br /><br />Mike--<br /><br />That would be great to have. Thanks. Tell me when you have it together. I'd love it have a copy.<br /><br />ranger

[[old] PaulS]

<!--QuoteBegin-Mike Niezgoda+Dec 30 2005, 07:09 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Mike Niezgoda @ Dec 30 2005, 07:09 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin-ranger+Dec 30 2005, 10:10 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(ranger @ Dec 30 2005, 10:10 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--><!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->SR = 30, SPI = 10.5, Drive Joules = 1049 (w/0.6sec Drive time), Pace = 1:43.6 </td></tr></table><br /><br />Ah. O.K. I get the joules business.<br /><br />So where do you get the drive time from?<br /><br />And how does drive time vary with drag? I am no longer rowing at 105 df. (setting 2). I am now rowing at 122 df. (setting 4).<br /><br />What is the drive time at 122 df., 1:44 @ 24 spm?<br /><br />This seems to be emerging as a new distance pace for me (e.g., 60min). This is pleasing. Again, 1:44 @ 24 spm is UT1 for a 6:16 2K.<br /><br />Do you have a list of various drive times at 12.5 SPI, 122 df., and a full spread of relevant rates (e.g., 16-44 spm)? If so, that might be useful to me.<br /><br />ranger <br /> </td></tr></table><br /><br /><br />Ranger,<br /><br />I am fairly certain that Paul is just assuming a drive time of 0.6 seconds. Drive Time is one of the "gobblity gook" metrics that ErgMonitor outputs.<br /><br />With a bit of time, I think I can put together a spreadsheet or a small program that allows you to enter the following metrics and calculate the missing metrics:<br /> - SPI<br /> - Stroke Rate<br /> - Stroke Count <br /> - Drag Factor<br /> - Drive : Recovery Ratio<br /> - Pace (seconds/500m)<br /> - Drive Length (cm)<br /> - Drive Time<br /> - Distance<br /> - Time for Distance<br /> - Drive Joules<br /><br />No promises on a time when I can get it done, but it is something I have been thinking about incorporating into the workout setup window in ErgMonitor.<br /> <br />- Mike <br /> </td></tr></table><br /><br />Indeed, just making a guess, as without a DF and Drive length, and exact figure would be impossible to come up with. I have been known to make pretty good "guesses" however... <br /><br />I will note that small changes in drive time, make pretty large differences in "drive joules".

[[old] ranger]

<!--QuoteBegin--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin--> am fairly certain that Paul is just assuming a drive time of 0.6 seconds. </td></tr></table><br /><br />I guess I am getting confused here.<br /><br />Tell me again. Why is the drive time shorter at the same SPI but at a higher rate and pace? Can't you just change the recovery-to-drive ratio as you move from one to the other so that the drive time remains about the same? Are you saying that if you are rowing at 12.5 SPI but at a 3-to-1 ratio at 20 spm and at a 1-to-1 ratio at 40 spm, the drive times are radically different? If so, that isn't very intuitive for me.<br /><br />ranger

[[old] John Rupp]

<!--QuoteBegin-Mike Niezgoda+Dec 30 2005, 07:09 AM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'><b>QUOTE(Mike Niezgoda @ Dec 30 2005, 07:09 AM)</b></div></td></tr><tr><td class='quote'><!--QuoteEBegin-->I am fairly certain that Paul is just assuming a drive time of 0.6 seconds.  Drive Time is one of the "gobblity gook" metrics that ErgMonitor outputs.[right] </td></tr></table><br /><br />You should point out, as you did in the other thread, that EM does not measure the entire length of the drive, but only the first portion of it to the peak. Then it counts the rest of the drive as "recovery".<br /><br />Thus someone with a drive time of 1.0 seconds and 1.0 seconds for recover, you would say has a drive time of 0.6s and a 30% drive to stroke ratio, whereas in reality the drive to stroke ratio is 50%.<br /><br />That is not accurate.<br /><br />If you are going to base all your other calculations on this, then they will likewise not be accurate.