Distance Per Stroke

[old] ranger · Post by **[old] ranger** » April 13th, 2005, 5:24 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE</div></td></tr><tr><td class='quote'>watts/time (spi): 11.32 </td></tr></table> Nice! 11.32 SPI is just right for a top lightweight. Unfortunately, at 54 years of age, managing 41 spm in a 2K is more than a little out of the question. Can't blow that much air. Can't rev the heart that high. But pulling 11.32 SPI is not at all out of the question. No problem with strength and technique. 11.34 SPI at 35 spm is a 6:24 2K. I'd be happy with that. ranger

[old] PaulS · Post by **[old] PaulS** » April 13th, 2005, 6:05 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 13 2005, 09:08 AM)</div></td></tr><tr><td class='quote'>SPI is meaningless </td></tr></table> Nice rant... While you are in interesting company with that point of view, I'll try to assist you a small bit. Let's say you have a group of rowers and have to select them based on Erg Scores (yeah, I know this doesn't have to be, but let's just go with it for a moment.), and the Athletes were free to do any rate that they wish. Does the guy who is 5 seconds slower, but also at a SR that was 5 lower win or lose the Erg selection? SPI is meaningful in the context of the individuals performances. For example, if you improve your 2k time by 1 second, by bringing your rate up 2 strokes/minute, what exactly was it that you improved? This is exactly the problem one faces when loudly proclaiming Slides to be an advantage in the face of contra-indicative scientific proof otherwise. So, if you don't want it to mean anything, that's fine, I invented it for my own use, and have not made any great claims to how it should be used, but provided a few ideas how it might be. Any other ideas are welcome. Cheers.

[old] jjpisano · Post by **[old] jjpisano** » April 13th, 2005, 7:32 pm

I don't want to open up a can of worms but..... I believe that one of the reasons that the Wolverine plan is so good is that the recovery rows are performed at a high SPI. Those workouts are at a low cardiovascular intensity; however, they still challenge the skeletal muscles' contraction intensity. Good hard skeletal muscle contraction intensity is immensely important for a successful 2K. But so is aerobic capacity immensely important. Aerobic capacity is most effectively trained with least unnecessary stress in the 60% to 80% of 2k watt range. I believe much of the recovery rows in the Wolverine plan are rowed for long periods at around 60% 2k watt intensity at high SPI i.e. low stroke rate. Jim Pisano

[old] NavigationHazard · Post by **[old] NavigationHazard** » April 13th, 2005, 8:42 pm

Just did a 100m piece in 14.98, 832 watts, 52 SPM, SPI = 16. (Oh to be able to keep that up.....) For these sorts of 'freak show' short sprints, comparatively high SPI doesn't necessarily imply low stroke rating. But for 'normal' training/racing distances,' it certainly does. For example, nobody on the planet can sustain even my geezerly 16/52 for an entire 2k (5:00 flat pace). And I totally agree, no one should try to do Wolverine recovery paddles that way

[old] PaulS · Post by **[old] PaulS** » April 13th, 2005, 9:04 pm

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(NavigationHazard @ Apr 13 2005, 04:42 PM)</div></td></tr><tr><td class='quote'>Just did a 100m piece in 14.98, 832 watts, 52 SPM, SPI = 16. (Oh to be able to keep that up.....) For these sorts of 'freak show' short sprints, comparatively high SPI doesn't necessarily imply low stroke rating. But for 'normal' training/racing distances,' it certainly does. For example, nobody on the planet can sustain even my geezerly 16/52 for an entire 2k (5:00 flat pace). </td></tr></table> But Pinsent maintained an SPI of about 18 for 30 minutes during their Fixed SR=20 test. And of course a relatively plodding 1:24.7 500M @ 43 is a SPI=13.3, but going 1:25.5 @ 10PS is a SPI=16, SR=35. Watch out for the "geezerly". If you don't have to keep it up for long, it's possible to do some extraordinary things. You must have had some pretty smoking Fastest Strokes in your 100M bash.....

[old] NavigationHazard · Post by **[old] NavigationHazard** » April 14th, 2005, 5:14 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(PaulS @ Apr 13 2005, 08:04 PM)</div></td></tr><tr><td class='quote'> But Pinsent maintained an SPI of about 18 for 30 minutes during their Fixed SR=20 test. And of course a relatively plodding 1:24.7 500M @ 43 is a SPI=13.3, but going 1:25.5 @ 10PS is a SPI=16, SR=35. Watch out for the "geezerly". If you don't have to keep it up for long, it's possible to do some extraordinary things. You must have had some pretty smoking Fastest Strokes in your 100M bash..... </td></tr></table> Heh, my 'geezerly' was intended as a reference to my own advancing years and decrepitude. As an athlete I have the ankles and knees of a 180-year-old, though my lungs, heart and arteries are those of a 178-year-old stripling. Pinsent I freely admit is a God and not bound by normal mortal constraints. As far as I know, Leo Young's 13.6 for 100m is the best around for that distance. He's said he got to 1:06/500m pace on stroke 3 when doing it. Now that's smoking. Graham Benton plays in the same league and no doubt there are others. It would be interesting to know what Young's stroke rate/ SPI for the 100m yank was, and also for his 1:10.5 500m. Something around 22 or 23 for the former wouldn't surprise me. Leo's also said that his training diary records a peak wattage of over 1400 a few years back, although he now can't remember many of the details. Over 50 or 60 m, he may well have been able to get his SPI up into the high 20s. Going the other direction, Jon Goodall has reported some heinously fast short-distance SPM rates from some of his 100k-relay record teammates. Graham Kirk, he says by way of example, "favoured 70-80 SPM" for the relay distance and once did 93 SPM for 10 seconds. True, in a relay you get a running start (i.e. the wheel is moving), and those spank-me stroke-per-minute ratings couldn't possibly have been full-slide....

[old] Dickie · Post by **[old] Dickie** » April 14th, 2005, 9:30 am

It's not a rant, what you are doing when dividing power by stroke rate is trying to obtain an average power per stroke, but you already have that. The wattage displayed on the monitor is already an average. If the monitor shows 200 Watts then the rower pulled an average of 200 watts on each stroke, regardless if he pulled 20spm or 25spm. Lets try an example Rower 1 pulls 20 spm and averages 200 Watts as shown on the monitor that is an SPI of 10 Rower 2 pulls 25 spm and averages 250 Watts as shown on the monitor that is also an SPI of 10 now who do you want, someone who pulls 200 watts on each stroke or someone who pulls 250 watts on each stroke. In selecting a crew, you want the people who generate the most power per stroke, by using the Average watts on the monitor, you have this, you don't need to divide by stroke rate as it is already done for you. The average watts is totals watts (which is not shown) divided by strokes Again SPI is meaningless

[old] Alan Maddocks · Post by **[old] Alan Maddocks** » April 14th, 2005, 10:57 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 08:30 AM)</div></td></tr><tr><td class='quote'>It's not a rant, what you are doing when dividing power by stroke rate is trying to obtain an average power per stroke, but you already have that. The wattage displayed on the monitor is already an average. If the monitor shows 200 Watts then the rower pulled an average of 200 watts on each stroke, regardless if he pulled 20spm or 25spm. Lets try an example Rower 1 pulls 20 spm and averages 200 Watts as shown on the monitor that is an SPI of 10 Rower 2 pulls 25 spm and averages 250 Watts as shown on the monitor that is also an SPI of 10 now who do you want, someone who pulls 200 watts on each stroke or someone who pulls 250 watts on each stroke. In selecting a crew, you want the people who generate the most power per stroke, by using the Average watts on the monitor, you have this, you don't need to divide by stroke rate as it is already done for you. The average watts is totals watts (which is not shown) divided by strokes Again SPI is meaningless </td></tr></table> Dickie, Look at it this way .... Rower 1 pulls 250 watts at 20 spm (SPI of 12.5) Rower 2 pulls 250 watts at 25 spm (SPI of 10.0) Assuming both could take their rate up to about the same rate (say 40 spm. over 2000m.), & both could maintain their SPI, which rower would you now want in your boat? See ........... SPI is relevant Cheers, Alan.

[old] PaulS · Post by **[old] PaulS** » April 14th, 2005, 11:13 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 05:30 AM)</div></td></tr><tr><td class='quote'>Again SPI is meaningless </td></tr></table> Nice Repeat. You want a meaningless unit, how about Calories? There's not much need to argue about this, I find plenty of "meaning" in SPI, but it has to be put in context of the larger picture. The rowers you are talking about are rowing a 2:00 @ 20 and a 1:51.5 @ 25. I can't really say which one would be more useful in a boat, it would all depend on how long each could keep the respective effort going. In fact, it's quite obvious that both could do the others task for at least some period of time. They may even be quite compatible in a boat. What you are trying to illustrate is that SPI, just like any other unit, has dependencies which subject it to manipulation. i.e. Pace is a reflection of Watts, which is the Joules (absorbed by the flywheel) / Stroke Time. But does nothing to take ratio into account (not such a big deal on the Erg, but a very big deal in a boat). The more appropriate question is, "If two people weigh exactly the same, pull the same Erg score, and are equaly skilled on the water, but one rated 30 and the other 25, which one do you want in the boat?". The higher SPI, simple.

[old] Dickie · Post by **[old] Dickie** » April 14th, 2005, 11:24 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Alan Maddocks @ Apr 14 2005, 10:57 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 08:30 AM)</div></td></tr><tr><td class='quote'>It's not a rant, what you are doing when dividing power by stroke rate is trying to obtain an average power per stroke, but you already have that. The wattage displayed on the monitor is already an average. If the monitor shows 200 Watts then the rower pulled an average of 200 watts on each stroke, regardless if he pulled 20spm or 25spm. Lets try an example Rower 1 pulls 20 spm and averages 200 Watts as shown on the monitor that is an SPI of 10 Rower 2 pulls 25 spm and averages 250 Watts as shown on the monitor that is also an SPI of 10 now who do you want, someone who pulls 200 watts on each stroke or someone who pulls 250 watts on each stroke. In selecting a crew, you want the people who generate the most power per stroke, by using the Average watts on the monitor, you have this, you don't need to divide by stroke rate as it is already done for you. The average watts is totals watts (which is not shown) divided by strokes Again SPI is meaningless </td></tr></table> Dickie, Look at it this way .... Rower 1 pulls 250 watts at 20 spm (SPI of 12.5) Rower 2 pulls 250 watts at 25 spm (SPI of 10.0) Assuming both could take their rate up to about the same rate (say 40 spm. over 2000m.), & both could maintain their SPI, which rower would you now want in your boat? See ........... SPI is relevant Cheers, Alan. </td></tr></table> In mathematics when doing a proof a mathemetician can come up with many examples that will prove his theory, however it only takes one bad example to disprove it, and i have done that.

[old] michaelb · Post by **[old] michaelb** » April 14th, 2005, 2:00 pm

So SPI is useful for comparing two rowers for a boat. But is it useful for guiding your training or determining the combination of your SR and your pace? My understanding is that is how Ranger and others use SPI. I would assume all of us would love to race a 2k at the highest SPI possible. Although I have gone away from it somewhat by rowing a little further than 10m, I usually row at 10 meters per stroke as my ratio. I find this a useful way to determine a reasonable SR for training pieces at a particular pace, and also I find that it teaches the habit of only increasing your SR when you are also increasing your power (measured in watts). Meters per stroke also seems to me to be much easier to understand as an expression of your power per stroke then SPI. So if I have this math correctly, comparing the paces that I would row at using either 10mps or SPI=10: 10 MPS= Pace Rate 2:10 23 2:05 24 2:00 25 1:55 26 1:50 27 1:45 29 1:40 30 1:35 32 SPI=10 Pace Rate MPS 2:10 16 14 2:05 18 13 2:00 20 12.5 1:55 23 11.5 1:50 26 10.5 1:45 30 9.5 1:40 35 8.5 If rowing with a constant SPI is my goal, that means my recovery pieces and my long training pieces are done at very low SRs. While that may be "good" for me, I would find rowing at SR of 16 or 18 for long distances uncomfortable and boring. I can see the value of occasionally rowing at artificially low SRs to build power and/or work on technique, but I would do that at high power. What is the value of low SRs and low power rowing? Even at the paces faster than my 2k pace, I would think for training it would be better to row those at a lower SR than what you would do in a race, instead of the high SRs that I get for rowing based on SPI.

[old] holm188 · Post by **[old] holm188** » April 15th, 2005, 3:54 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 10:24 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Alan Maddocks @ Apr 14 2005, 10:57 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 08:30 AM)</div></td></tr><tr><td class='quote'>It's not a rant, what you are doing when dividing power by stroke rate is trying to obtain an average power per stroke, but you already have that. The wattage displayed on the monitor is already an average. If the monitor shows 200 Watts then the rower pulled an average of 200 watts on each stroke, regardless if he pulled 20spm or 25spm. Lets try an example Rower 1 pulls 20 spm and averages 200 Watts as shown on the monitor that is an SPI of 10 Rower 2 pulls 25 spm and averages 250 Watts as shown on the monitor that is also an SPI of 10 now who do you want, someone who pulls 200 watts on each stroke or someone who pulls 250 watts on each stroke. In selecting a crew, you want the people who generate the most power per stroke, by using the Average watts on the monitor, you have this, you don't need to divide by stroke rate as it is already done for you. The average watts is totals watts (which is not shown) divided by strokes Again SPI is meaningless </td></tr></table> Dickie, Look at it this way .... Rower 1 pulls 250 watts at 20 spm (SPI of 12.5) Rower 2 pulls 250 watts at 25 spm (SPI of 10.0) Assuming both could take their rate up to about the same rate (say 40 spm. over 2000m.), & both could maintain their SPI, which rower would you now want in your boat? See ........... SPI is relevant Cheers, Alan. </td></tr></table> In mathematics when doing a proof a mathemetician can come up with many examples that will prove his theory, however it only takes one bad example to disprove it, and i have done that. </td></tr></table> Fred, In your example of 2 rowers you have missed the main point which makes SPI useful: for how long can your rowers keep up their Watts, SR, SPI. If you leave that variable open then SPI is useless, but if you fiwx the time that your rowers maintain their watts and check how much SPI they loose when they increase their rates over a 2k, then you can use it. Also, what is total watts? Watts are Joules divided by time. So you if you want to know the total amount of energy produced (put into the flywheel) you can look at the calories and multiply by 4.18 to get the Joules not Watts. SPI is Joules divided by number of strokes taken to produce those Joules (maybe with a constant multiplication factor (maybe 60 or 1/60) to get the units right). But if you do not like SPI, there is other ways of checking the efficiency of your stroke!!

[old] Dickie · Post by **[old] Dickie** » April 15th, 2005, 9:42 am

<table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(holm188 @ Apr 15 2005, 03:54 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 10:24 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Alan Maddocks @ Apr 14 2005, 10:57 AM)</div></td></tr><tr><td class='quote'><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><div class='genmed'>QUOTE(Dickie @ Apr 14 2005, 08:30 AM)</div></td></tr><tr><td class='quote'>It's not a rant, what you are doing when dividing power by stroke rate is trying to obtain an average power per stroke, but you already have that. The wattage displayed on the monitor is already an average. If the monitor shows 200 Watts then the rower pulled an average of 200 watts on each stroke, regardless if he pulled 20spm or 25spm. Lets try an example Rower 1 pulls 20 spm and averages 200 Watts as shown on the monitor that is an SPI of 10 Rower 2 pulls 25 spm and averages 250 Watts as shown on the monitor that is also an SPI of 10 now who do you want, someone who pulls 200 watts on each stroke or someone who pulls 250 watts on each stroke. In selecting a crew, you want the people who generate the most power per stroke, by using the Average watts on the monitor, you have this, you don't need to divide by stroke rate as it is already done for you. The average watts is totals watts (which is not shown) divided by strokes Again SPI is meaningless </td></tr></table> Dickie, Look at it this way .... Rower 1 pulls 250 watts at 20 spm (SPI of 12.5) Rower 2 pulls 250 watts at 25 spm (SPI of 10.0) Assuming both could take their rate up to about the same rate (say 40 spm. over 2000m.), & both could maintain their SPI, which rower would you now want in your boat? See ........... SPI is relevant Cheers, Alan. </td></tr></table> In mathematics when doing a proof a mathemetician can come up with many examples that will prove his theory, however it only takes one bad example to disprove it, and i have done that. </td></tr></table> Fred, In your example of 2 rowers you have missed the main point which makes SPI useful: for how long can your rowers keep up their Watts, SR, SPI. If you leave that variable open then SPI is useless, but if you fiwx the time that your rowers maintain their watts and check how much SPI they loose when they increase their rates over a 2k, then you can use it. Also, what is total watts? Watts are Joules divided by time. So you if you want to know the total amount of energy produced (put into the flywheel) you can look at the calories and multiply by 4.18 to get the Joules not Watts. SPI is Joules divided by number of strokes taken to produce those Joules (maybe with a constant multiplication factor (maybe 60 or 1/60) to get the units right). But if you do not like SPI, there is other ways of checking the efficiency of your stroke!! </td></tr></table> Don't introduce Calories, they are garbage and are dependent on to many other factors. By the way the Calorie you are referring to above are a Physical Calorie or the amount of energy required to raise the temperature of 1cc of water 1 degree centigrade they are not a Food Calorie that is shown on the monitor which are actually K/Cal's or Kilo-Calories or 1000 of the calories you are referring to. You also state that I miss the point because I ignore "for how long can your rowers keep up their Watts, SR, SPI". Here you are missing the point as you now seem to need more info to justify SPI. If SPI is no good unless you know the time or distance etc. then it is no good period. Answer me this. Since the Monitor Displays an average Watts at the end of the piece which is by definition total watts divided by strokes. What purpose is served by dividing this number by strokes a second time. SPI is meaningless. I have shown one example where it makes no sense so how can you trust it. Here is another example. Rower 1 pulls 250 Watts average at 25spm giving an SPI of 10 this rower would complete a 2k in approximately 7:27 Rower 2 pulls 280 Watts average at 32spm giving an SPI of 8.75 this rower would complete a 2k in approximately7:11 Here a lower SPI is better. Now how about using it to select members of a crew. I am not a coach and have great respect for Paul Smith but lets think about this. In selecting oarsmen for a four or eight, you need people that can work together, they have to pull at the same rate. You need people that can produce the greatest power at that rate, whatever it is. So you need to test your athletes at that rate or you risk selecting someone that may be great doing his own thing on the erg but falls apart when he has to row along with the rest of the crowd. Finally I like Paul Smith, I do respect his ability as an Oarsman and a coach., but I have had reservations on the usefulness of SPI for a long time. I had intended to talk to him personally at the recent CRASH-B's but could not attend. I am only responding now because SPI has taken on a life of its own and many people are using it in their training. I believe it is meaningless and could lead people in the wrong direction in their training. I think the major opposition I have now is defensive in nature because all retorts so far have been similar to - "You don't understand because you have not also taken x into account" if you put the defensiveness aside and think about it you can come up with just as many examples of its failure as its success. There are lots of numbers out there, just because you can divide them to get an index does not make it useful or meaningful you have to consider the numbers. I have put forth 2 examples of SPI that do not indicate the best rower. How can you trust the SPI to be correct in any other instance.

[old] Alan Maddocks · Post by **[old] Alan Maddocks** » April 15th, 2005, 10:55 am

Dickie, With all respect you have not! The logic of your argument is that we can all row faster by increasing the rate. BUT there is an upper limit to how many spm we can maintain over 2000m. If every rower in a race achieved this upper limit (let's say, for arguments sake 45 spm.), then the rower with the most powerful stroke (i.e. highest SPI) would by definition win. e.g. 45 spm x SPI of 10 = 450 watts 45 spm x SPI of 11 = 495 watts ERGO SPI matters Alan.

[old] PaulS · Post by **[old] PaulS** » April 15th, 2005, 10:59 am

Hey Fred, We agree completely on this point! "SPI has taken on a life of its own and many people are using it [incorrectly] in their training" Remember the "I" is for "index", and index has a dependencies. How many times have I said that SPI is not a "Pure unit" that indicates anything? It must be placed in context. Likewise, there are other things that need context as well, that's why the "STP" exists in science, I've seen water "boil" at room temperature (very low pressure however), the speed of sound depends on the medium through which it is travelling, etc...... An example you might appreciate is that just because a person can lift 100lbs twice is no proof that they will be able to lift 200lbs once. (but both did the same amount of work) That people come up with novel ways to use SPI, is certainly interesting, and frankly I'm not sure what the danger is in that. Finally, when you are fighting for a new PB and finally get it, check the SPI against the previous PB to see if it was merely due to a higher SR or some other fitness gain. Cheers!

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