Concept2 Forum

Ive been thinking about power vs. stroke rate during a 2k.

Would it be more efficient to pull at a lower rate of about 27 or 28 and put lots of power into each stroke,

or row at a 31 or 32 and not put so much power in each stroke?

any thoughts?

It's more efficient to keep the flywheel as close to it's mean power dissipation as possible, but we don't have a real shot at getting particularly close to that because of the cyclic and interupted nature of our power input in rowing.

If I were to propose a general rule, I would say that you want to arrive at a combination that ends up covering the 2k in 200-240 strokes, which is really a very wide range, but it also has to cover a very wide range of stroke lengths, DF's, and athletic abilities.

Distance per Stroke (DPS) tends to get shorter as the rate increases, but if it gets too short you end up going no faster for a higher rate, at that point wasted effort is piling up quickly.

I't quite a balancing act to get it all right, but fortuantely we have a PM right in front of us that indicates if something is productive or not, just don't believe any single stroke output, tak them in groups of 3 or 4 so that the variables we might unwittingly manipulate for 1 or 2 get accounted for.

Ultimately you are trying to imporve your power per stroke, but this is also not something that should be gamed by using excessively low ratings, as that is not how it will be put to use in a race. Genuine improvement there usually takes place in the decimal values for consistent training, not the whole numbers.

PaulS wrote: If I were to propose a general rule, I would say that you want to arrive at a combination that ends up covering the 2k in 200-240 strokes, ...

Paul,
You often mention the total number of strokes as an important number. For example you in the thread on 40+ stroke ratings you mentioned that someone would have a very hard time in a 2K with 300 strokes vs 240.

Seems to me that the stroke rating is simply a trade off between the inefficiencies of moving the body more times and reversing muscle direction, and the inefficiencies of the speed variation of the fly wheel. The faster the split the more advantage there is to higher ratings. The total number of strokes seems to be a secondary consequence of things that are more important.

I could certainly see a small light person who is arobically fit being optimally efficient significantly at 300 strokes for 2K.
Nosmo

Nosmo wrote:Seems to me that the stroke rating is simply a trade off between the inefficiencies of moving the body more times and reversing muscle direction, and the inefficiencies of the speed variation of the fly wheel.

I'm a newcomer without rowing knowledge, but I would have thought that there is a balance of energy cost needed to alter momentum of body vs fan. Maybe the energy cost of directional change in a large, heavy rower would favour a slightly slower spm.

Nosmo wrote:

PaulS wrote: If I were to propose a general rule, I would say that you want to arrive at a combination that ends up covering the 2k in 200-240 strokes, ...

Paul,
You often mention the total number of strokes as an important number. For example you in the thread on 40+ stroke ratings you mentioned that someone would have a very hard time in a 2K with 300 strokes vs 240.

Seems to me that the stroke rating is simply a trade off between the inefficiencies of moving the body more times and reversing muscle direction, and the inefficiencies of the speed variation of the fly wheel. The faster the split the more advantage there is to higher ratings. The total number of strokes seems to be a secondary consequence of things that are more important.

I could certainly see a small light person who is arobically fit being optimally efficient significantly at 300 strokes for 2K.
Nosmo

Well, I'll make another generalization. We'd have to look at "Fast" rather than "Slow" rowers first, which does include some lightweights, but not many, and they do have yet to go sub-6 in a reported event over the last 26 years. The Biggest and Fastest would likely have come the closest to an efficiency balance. Graham Benton is pretty fast, and has a huge Distance per stroke, yet he is not the "fastest" by quite some margin. He is also not quite as big as the guys who are faster and they manage to rate higher to get there. I doubt they would be slower than Graham even if matching stroke for stroke, but that would be interesting to see.

Many are fooled by the allure of rating higher for a faster pace, but it truly has not worked out to be a benefit outside my fairly wide range. I suppose I could narrow the range to 200-220 total strokes for a 2k, and that count would encompass the majority of top performances. Please feel free to discuss further. There has been some research into stroke count and it's importance in optimal performance.

Snail Space wrote:

Nosmo wrote:Seems to me that the stroke rating is simply a trade off between the inefficiencies of moving the body more times and reversing muscle direction, and the inefficiencies of the speed variation of the fly wheel.

I'm a newcomer without rowing knowledge, but I would have thought that there is a balance of energy cost needed to alter momentum of body vs fan. Maybe the energy cost of directional change in a large, heavy rower would favour a slightly slower spm.

I guess I wasn't clear but we are saying mostly the same thing. In addition to you mention, there is some inefficiency in having to fire the muscles more times. The better trained on is the easier that becomes. Good cyclists can often spin at 200+ RPM. Many recreational cyclist have trouble at 100.

PaulS wrote: Well, I'll make another generalization. We'd have to look at "Fast" rather than "Slow" rowers first, which does include some lightweights, but not many, and they do have yet to go sub-6 in a reported event over the last 26 years. The Biggest and Fastest would likely have come the closest to an efficiency balance. Graham Benton is pretty fast, and has a huge Distance per stroke, yet he is not the "fastest" by quite some margin. He is also not quite as big as the guys who are faster and they manage to rate higher to get there. I doubt they would be slower than Graham even if matching stroke for stroke, but that would be interesting to see.

Many are fooled by the allure of rating higher for a faster pace, but it truly has not worked out to be a benefit outside my fairly wide range. I suppose I could narrow the range to 200-220 total strokes for a 2k, and that count would encompass the majority of top performances. Please feel free to discuss further. There has been some research into stroke count and it's importance in optimal performance.

From:
http://www.concept2.co.uk/wirc/race_ana ... sen&race=3
Henrik Stephansen, a light weight did a 6:06 at what looks like about a 42 or 43 average, which would be 260 strokes. He positive splits so maybe he could have gone faster, but it does seem to work for him.

I think your distinction between fast and slow people actually supports my point. Those doing sub 6:00 are going to be tall and muscular. I would bet if you looked at the most efficient rate for people as a function of size (choose a body type so weight and height scale monotonically) then the optimal stroke rating will increase with speed and decrease with body size.

Still seams to me that number of strokes is secondary. It just a function of other factors that are more important. Which is not to say that you are wrong about the optimal number of strokes. Just that it is a consequence of other things that are more important.

Looking at the results of the crash-B, I esstimatged the strokes taken for the top rowers. These I think are pretty close (within 10 strokes) but the are quick estimates.

Open events only. THese are the first five that had stroke rating graph the data. Not necessarily the top 5 over all

Hwt M; LtwM; HwtW; LtwW
180 256 242 256
214 183 198 245
206 240 217 260
208 262 225 262
200 216 211 252

Again this indicates that the heavier the person the lower the optimal stroke rating. I would expect that the taller the rating the lower the stroke rating also. So the 200-220 stroke rule seems to apply for hwt Men, but not necessarily others.

If you limit it to those under 5 feet, I'd bet optimal is well above 260.

Nosmo wrote:Looking at the results of the crash-B, I esstimatged the strokes taken for the top rowers. These I think are pretty close (within 10 strokes) but the are quick estimates.

Open events only. THese are the first five that had stroke rating graph the data. Not necessarily the top 5 over all

Hwt M; LtwM; HwtW; LtwW
180 256 242 256
214 183 198 245
206 240 217 260
208 262 225 262
200 216 211 252

Again this indicates that the heavier the person the lower the optimal stroke rating. I would expect that the taller the rating the lower the stroke rating also. So the 200-220 stroke rule seems to apply for hwt Men, but not necessarily others.

If you limit it to those under 5 feet, I'd bet optimal is well above 260.

I'm 47, Coxswain sized...5'1", 128 lbs (at ideal weight...138 lbs now). I find that I do best at a relatively high SPM rate because of my height...and quickness. Should I be aiming for, eventually, doing 40+ SPM? I'm not yet advanced enough to do that now (mid 30s is the best I can do now over 2K), but in the future would a 40s+ rate make sense for me?

WorldTed

worldted wrote:
I'm 47, Coxswain sized...5'1", 128 lbs (at ideal weight...138 lbs now). I find that I do best at a relatively high SPM rate because of my height...and quickness. Should I be aiming for, eventually, doing 40+ SPM? I'm not yet advanced enough to do that now (mid 30s is the best I can do now over 2K), but in the future would a 40s+ rate make sense for me?

WorldTed

If your stroke rating is now in the mid thirties, loose 10 lbs and you'll have a much easier time going higher. However, these are (my understanding of) general rules and the only way to be sure is to experiment and see what works for you.

Nosmo wrote:

worldted wrote:
I'm 47, Coxswain sized...5'1", 128 lbs (at ideal weight...138 lbs now). I find that I do best at a relatively high SPM rate because of my height...and quickness. Should I be aiming for, eventually, doing 40+ SPM? I'm not yet advanced enough to do that now (mid 30s is the best I can do now over 2K), but in the future would a 40s+ rate make sense for me?

WorldTed

If your stroke rating is now in the mid thirties, loose 10 lbs and you'll have a much easier time going higher. However, these are (my understanding of) general rules and the only way to be sure is to experiment and see what works for you.

Great point about need to lose that last 10 lbs, especially with someone my size. That should help my rowing (and life in general) a lot.

WorldTed

worldted wrote:
Great point about need to lose that last 10 lbs, especially with someone my size. That should help my rowing (and life in general) a lot.

WorldTed

I never said you "needed" to lose 10 lbs. Just that it should help if you wanted to row faster. Big difference.

Nosmo wrote:

worldted wrote:
Great point about need to lose that last 10 lbs, especially with someone my size. That should help my rowing (and life in general) a lot.

WorldTed

I never said you "needed" to lose 10 lbs. Just that it should help if you wanted to row faster. Big difference.

Make no mistake, I NEED to lose 10 lbs.

Nosmo wrote:

worldted wrote:
Great point about need to lose that last 10 lbs, especially with someone my size. That should help my rowing (and life in general) a lot.

WorldTed

I never said you "needed" to lose 10 lbs. Just that it should help if you wanted to row faster. Big difference.

But could he row even faster by transforming that 10lbs into lean muscle?

It would seem so, based on the small differences in overall performance once lwts and hwt are in their boats, with likely similar body compositions.
i.e. Hull drag does increase for the hwts, but not quite as quickly as they can increase the available power.

worldted wrote:Make no mistake, I NEED to lose 10 lbs.

You can do it!