The ideal stroke rate

[jjpisano]

Do you think that the ideal stroke rate for a person can be figured out from the equations on the page at the physics of rowing web site?

http://www-atm.physics.ox.ac.uk/rowing/ ... #section13

Basically the page details how to figure out how much energy is being used just moving up and down the slide.

That in conjunction with the energy applied to the flywheel is the total energy of the rower on the ergometer. We often don't think about the unmeasured energy of just going back and forth.

The equations take into account stroke rate, the rowers mass and the rowers stroke length.

One question immediately pops in my head: are there different ideal rates for the same person if that person is doing different distances, eg. the ideal stroke rate for a 2k versus a 500m versus versus a 10k.

Just thought I'd throw the question out there among the forumites and see if anyone has ideas on the subject.

I advocate doing time trails at a "natural" stroke rate, i.e. whatever feels right. But that's not very precise. I'm guessing that the question is very complicated and the answer can not be limited by an equation like the one on the physics of rowing web site because it probably involves muscle contractility speed and the limits of human size and strength. But if you think there is a way to figure out a precise ideal, I'd love to hear about it.

[johnlvs2run]

The rating that helps you to go the fastest for that distance is the best one.

[jjpisano]

John:

I thought you'd be the first to answer this one. You have, in the past, always advocated copying the stroke rate that world record holders used when they set their world records.

So as a 40 year old male lightweight, if I were to do a 2k, I should look up the world record for my weight class and age group and gender, find out what stroke rate the record was performed at and mimic that stroke rate. That is after all the ideal performance.

That is one idea. Any other ideas on the subject?

[tomhz]

Jim,

I am sure that if you work out the mathematics, you will find that the optimal stroke rate is zero! At least: very low. Independant of weight and height.

Unfortunately, for a a reasonable pace this requires a stroke force that no man can apply. The problem with the formula is that is does not consider any biomechanical factors. And these factors are quite complex and differ from one person to another.

Tom

[RowtheRockies]

Jim,

Wow, I took one look at that link and it all looked like Greek to me! Math has never been a strength of mine so I didn't really bother trying to make sense of it.

My gut tells me that yes there is an ideal rate and that there is a different ideal rate for each distance. To me, it makes sense that each persons ideal rate has more to do with whether your phsical makeup leans more toward strength/power or more towards endurance. Seems to me if your background is running and you have a lot of aerobic endurance you will do better off rating higher. If you are more strength/power oriented you would be better off rating lower.

I can pull a faster 2K if I rate at 32 than I can at 20. Probably somewhere in between is my ideal stroke rate. On the flip side, I am sure I can pull a faster 2K at 32 than I can at 50 (never tried it).

The million dollar question is how does one determine their ideal rate however I do not think that can be answered by math alone.

Rich

[RowtheRockies]

To add on to that, at the end of a 2K that I rate say 32, I am absolutely dead and feel like my heart will explode out of my chest. At the end of a 2K r20, while my muscles feel dead, my HR is not maxed out, I just physically can't pull any harder. Makes sense to me that the reason behind this is that my my muscular power is not yet as developed as my aerobic engine and therefore can not fully utilize my aerobic capacity.

This is why I like and seem to be responding better to low rate training. My hope is that my muscular power is steadily increasing and able to use more of my aerobic capacity.

I think an example that illustrates this is my progress so far on the "Pisano Plan". I set my initial work rate for the cycle based 80% of the wattage I pulled in an all out 2K r20 TT. At first maintaining 188 Watts for 20 minutes was difficult and I was pretty damn whooped physically not Phsiologically. I am now doing 38 minutes and not feeling physically or physiologically whooped at the end. I think my muscles are able to use more of my aerobic capacity now.

You asked me once if at the end of a session if I felt it was to easy, just right or Hard. I don't know this for sure but I seem to remember you said you felt dead at the end of your sessions. Maybe this is because your muscles are on an even keel with your aerobic engine and making full use of it.

Just my 2 cents.

Rich

[Mike Caviston]

I’ve touched on this topic a few times in conjunction with discussing the Wolverine Plan, so apologies if this is repetitive. But it’s a good topic for framing some important points regarding training & performance. Performance is determined by a number of biomechanical, physiological, neurological, and psychological factors. It is possible that varying one training parameter – such as stroke rate – will have a negative impact on one aspect of performance while simultaneously having a positive impact on another. Whether performance is ultimately enhanced depends on the relative positive or negative effects. For example, in cycling (especially at top speeds) riders maintain a very closed, tucked position. This has a detrimental effect on ventilation, circulation, and the length-tension curve of some primary muscles. But all of this is more than compensated for by a reduction in aerodynamic drag. In rowing, there’s a trade-off between the cost of moving the body’s mass back and forth on the slide more times per minute vs. the savings of minimizing velocity fluctuations with a higher stroke rate. An athlete’s mass, stroke length, ratio of aerobic-to-anaerobic capacities, technical skill, and no doubt other factors will interact to determine what is the optimal rate for a given athlete at a given power output. One other factor to be considered is psychological, and how hard a particular rate/power output combination “feels” to the athlete. In cycling, it has been noted that for a given power output, the most efficient cadence (the one that results in the smallest amount of O2 being consumed) is generally 50-60rpm. Yet it is consistently found that athletes have greater endurance (are able to sustain a given power output longer) when using a cadence of 90-100rpm. In other words, in this instance athletes are (counter intuitively) able to last longer at a cadence that actually requires more oxygen to be consumed. Some researchers feel this is because at the higher cadence, the effort per stroke is less and feels easier to the athlete. I’m sure this phenomenon must have parallels in rowing.

Mike Caviston

[tomhz]

In cycling, it has been noted that for a given power output, the most efficient cadence (the one that results in the smallest amount of O2 being consumed) is generally 50-60rpm. Yet it is consistently found that athletes have greater endurance (are able to sustain a given power output longer) when using a cadence of 90-100rpm. In other words, in this instance athletes are (counter intuitively) able to last longer at a cadence that actually requires more oxygen to be consumed. Some researchers feel this is because at the higher cadence, the effort per stroke is less and feels easier to the athlete. I’m sure this phenomenon must have parallels in rowing.

Mike Caviston

Mike, I agree with your post in general but I don't agree with the above quote. An athlete is not interested in efficency perse. He wants to maximize power output at a given effort or minimize effort at a given, high, power output and he wants to known at what rpm for cycling or strokes per minute at rowing this is achieved. That is not the same as maximizing efficiency.
I can believe that efficiency defined as power output divided by effort was found maximal at 50-60spm with a self-chosen low power output but this is not true with higher power output of say 200W or higher. Well-trained cyclists all do their time trials at 100-120rpm. This is because they want to maximize their power output for the given effort they can sustain during the race and not because they want to increase their efficiency from 25% to 28% or because of some psychological effect.
It is known that some studies of optimal cadance in cycling missed this point. Their results are true but of no interest for racing.

The same is true for rowing. If I ask you to row a 9 min 2K while using little energy as possible you probably would choose a stroke rate around 20. But if I ask you to row it as fast as you can you would choose a stroke rate of 31-33 and maybe a little higher in the end (Crash-B 2006 )
There is little psychology in that.

Tom

[PaulS]

Having used cycling during the summers back in college to stay in shape, participating in the local time trials and such, it's really such a different thing from rowing that parallels woudl be difficult to draw. Cycling is a rather constant force input activity whereas rowing is extrememly intermittent by comparison. i.e. Cyclists aren't attached to the pedals just to keep their feet from slipping off, it's to use the entire circular path in driving the system forward, and getting the positioning and technique down very well takes some good practice, which is much like rowing.

When doing a VO2Max test using a cycle ergometer I was asked to maintain a cadence of 60, and I had no idea why that was, but hey, I was following directions. It was in fact extrememly miserable to pedal at that low rate, but I managed to keep going until reaching the machines resistance maximum which was getting rather tough, but as soon as they said to "increase the cadence" it was like having a weight lifted from my legs and continued for quite some time. My sense of what happened was that the increase of contraction speed was something that my muscles much prefered over the slow slogging cadence.

The parallel in rowing is more like velodrome cycling where a fixed gear must be chosen (rigging), but even with that, the intermittent force application with more time coasting than driving is problematic, and is complicated by the variable level of resistance that will be encountered while trying to advance the whole system across the water efficiently. It's doubtfull that when rowing we could ever reach the same contraction speed as can be done on a bicycle, at least not with conventional equipmeent and rigging, it's more like being stuck on that 50-60 cadence climbing a hill.

[johnlvs2run]

Therefore, when rowing, aim for a cadence of 50-60 strokes per minute, like you are climbing a hill.

[Mike Caviston]

Mike, I agree with your post in general but I don't agree with the above quote. An athlete is not interested in efficency perse. He wants to maximize power output at a given effort or minimize effort at a given, high, power output and he wants to known at what rpm for cycling or strokes per minute at rowing this is achieved. That is not the same as maximizing efficiency.
I can believe that efficiency defined as power output divided by effort was found maximal at 50-60spm with a self-chosen low power output but this is not true with higher power output of say 200W or higher. Well-trained cyclists all do their time trials at 100-120rpm. This is because they want to maximize their power output for the given effort they can sustain during the race and not because they want to increase their efficiency from 25% to 28% or because of some psychological effect.
It is known that some studies of optimal cadance in cycling missed this point. Their results are true but of no interest for racing.

Clearly you’ve read High-Tech Cycling by Edmund Burke. On p. 102 Burke writes “In general, during laboratory tests performed by noncyclists at constant power outputs (usually < 200W), pedaling at low rates (50 to 70rpm) resulted in lower oxygen uptake (VO2) than pedaling at higher rates (>90rpm). In any case, such generalization is of little practical value… We should therefore be cautious when applying the findings of previous research concerning cadence optimization to highly trained cyclists.” But I wasn’t doing any such thing. I was merely pointing out an observed phenomenon. I just sorted through a stack of articles on this topic published in peer-reviewed journals during the past decade, and several utilize trained/experienced cyclists working between 250-400W. It is true that at higher power outputs the most economic cadence will be > 50-60, but the freely-chosen cadence of trained cyclists will still tend to be higher than the most economic cadence. For example, see Marsh & Martin (“Effect Of Cycling Experience, Aerobic Power, and Power Output On Preferred and Most Economical Cycling Cadences”, Medicine & Science In Sports & Exercise, vol. 29, pp. 1225-1232, 1997): “Regardless of cycling experience and fitness level, the most economical cadence is not influenced by increases in power output and is always less than preferred cadence, suggesting that minimization of aerobic demand is not a key determinant of preferred cadence selection”. See also Chavarren & Calbet (“Cycling Efficiency and Pedaling Frequency In Road Cyclists”, European Journal of Applied Physiology, vol. 80, pp. 555-563, 1999); Van Soest & Casius (“Which Factors Determine the Optimal Pedaling Rate In Sprint Cycling?”, Medicine & Science In Sports & Exercise, vol. 32, pp. 1927-1934, 2000); and Lucia, Hoyos, and Chicharro (“Preferred Pedaling Cadence In Professional Cycling”, Medicine & Science In Sports & Exercise, vol. 33, pp. 1361-1366, 2001).

So I wasn’t making any claim about what cadence is “optimal” for professional cyclists doing time trials. Yes, cyclists want to maximize TT performance, not efficiency – which is exactly my point. Wouldn’t logic lead us to expect the most economic cadence to result in the best performance during an endurance trial? But the fact that it doesn’t means there are other even more important determinants of performance. To reiterate my main point from my previous post: performance involves a complex interaction of variables that sometimes conflict with one another. Which variable should be prioritized depends on the relative positive or negative impact each variable has. This thread was started under the supposition that in rowing, there will be an optimal stroke rate to minimize the loss of energy in various ways (back-and-forth movement of the athlete vs. deceleration/acceleration of the flywheel). I am just suggesting the possibility of some other governing factor, and doing “whatever feels right” may have more scientific justification than the original author apparently thought.

Mike Caviston

[tomhz]

Mike,

I didn't know about the cycling test results that show that even at higher power output the self-chosen cadance is higher than the cadance that uses the least oxygen. Thanks for that. Do you known of any studies in which the athletes were racing time trials at restricted cadance? It would be interesting to known the relation between restricted cadance and resulting power output.
So we agree that athletes should not be advised to race their time trial at the cadance that uses the least oxygen. Like you said: doing "what feels right" (maybe we should add : what is done by most trained athletes) seems the best way to choose a proper cadance.

Back to erging: What stroke rate is used by most trained athletes? This plot shows the results of all 800 participants of the EIRC 2004.



Tom

[JimR]

Back to erging: What stroke rate is used by most trained athletes? This plot shows the results of all 800 participants of the EIRC 2004.

Instead of a scatter plot could you show a bar graph that has the number of rowers for ranges of stroke rates? I'm thinking the number of people who went at a 27.x, 28.x, etc.

JimR

[tennstrike]

This plot shows the results of all 800 participants of the EIRC 2004.



Tom

Could you make the underlying data available or supply a link where it is available.

Thanks,

[tomhz]

Back to erging: What stroke rate is used by most trained athletes? This plot shows the results of all 800 participants of the EIRC 2004.

Instead of a scatter plot could you show a bar graph that has the number of rowers for ranges of stroke rates? I'm thinking the number of people who went at a 27.x, 28.x, etc.

JimR

This scatter plot shows that faster rowers tend to use somewhat higher stroke rates. A bar graph does not show that.

Tom