Why use Watts on Ergs???
nickystaite
to help answer!
(A sweep is the surf boats semi equivalent of a coxswain but at least
twice the weight as they use their body weight to steer the boat down
waves- also often the coach of the crew).
>It may be a silly question but how is the Watt's score on a concept ergo derived?
>I know Watts are joules per second, so is the watt's score the total joules per time (length) of >the stroke (average Watts) or is the 'peak' Wattage displayed?
>To the smart ar*es: I know to get the Wattage higher I just have to pull harder.
>Just trying to get my head around it because I prefer to have it set on time/500m and my >sweep prefers me to have it on Watts for some drills.
wmar...@gmail.com
Um.. Watts is linear? "splits" isn't linear because it estimates the
speed you'd go in a viscous medium (water) by dealing with the
acceleration/deceleration of a fan in a viscous medium (air). The
speed/power/acceleration is calculated based on the acceleration/
deceleration of the flywheel, which is measured and computed via the
little magnets embedded in the flywheel passing under a "sensor", and
sending a pulse to whatever unit it is in the monitor.
Concept 2 used to publish their formula for computing watts - do they
still?
W
Teaplant
> Concept 2 used to publish their formula for computing watts - do they
> still?
I believe that the loss of (rotational) KE of the spinning disk is
calculated stroke by stroke. This is done by sensing the peak rpm (at
end of drive phase) and minimum rpm (just before catch) and figuring
out the energy change (0.5*moment of inertia*angular velocity squared
for those still awake). The rower is clearly replacing this KE each
stroke and so the recorded power is the rate at which this energy is
being restored to the wheel. I imagine it is averaged over three
strokes or so to stabilise the output. (ie power = sum of last three
energy inputs divided by the time taken for those three complete
strokes). Don't know the exact algorithm but I think I read this
somewhere a long time ago.
Its quite neat because it means that damper settings/ratings etc are
all scaled out of the answer...
teaplant.
Pete
It's the average power output through the stroke (and recovery).
If you're doing several pieces stepping up the work, then it's
probably better to step up watts than split (or at least be aware that
if you do 1:50-1:45-1:40 then there is a much bigger power difference
between the second and third pieces than first and second; and you'll
feel it). If you care about being very accurately on a pace, watts is
better: there's a fair bit of difference between 1:50.0 and 1:50.9
split, but both will just show up as '1:50' on the monitor.
Pete
paul_v...@hotmail.com
Actually a displayed 1:50 could be from 1:49.5 to 1:50.4. But you are
correct about the Avg power per stroke cycle. But how many
consecutive strokes will show the exact same displayed pace anyhow?
My PR is 37 while trying, but it's more like 8-10 during any regular
session before a faster or slower pace is displayed for at least 1
stroke. Using Watts is a good way to divert yourself from being
obsessed with a particular pace, but Cal/hr would serve the same
purpose for that. The PM speaks several languages, pick the one you
like and go with it. [:o)
If you want your pace displayed to one decimal place you can always go
with ErgMonitor (tm). EM also shows Watts without having to change
screen modes, plus a bunch of other stuff. (slight understatement)
LOL
- Paul Smith
James Elder
> >It may be a silly question but how is the Watt's score on a concept ergo derived?
I have known coaches who like to use watts to calculate an extreme
form of weight adjustment as a selection aid for crews where all
athletes are at a similar weight i.e. lightweights:
e.g. Measure watts/kg for a 2k test.
kc
Just curious (not a jab, honestly) did you ever figure out how EM's
instantaneous power numbers are calculated (i.e. each power data point
on one of the power curves)? They don't equal handle force x handle
velocity, so I've been curious what the numbers do equal (i.e. what do
they mean).
-KC
paul_v...@hotmail.com
Magic. That's why the Pace works out to be so close to the PM.
Sorry, I can't take you seriously after learning how you perceive your
dogs level of intelligence.
Jab away.
- Paul Smith
KC
No wonder you support people like Palin and W. If you're comfortable
selling a product you don't understand and can't explain, it makes sense
you'd be comfortable with leaders who don't understand and can't explain
... anything. (Note I left McCain out of that comparison, whom I think
actually has a decent level of intelligence.)
My question wasn't a jab. It was serious. I'm sorry you can't seem to
let go of remarks made in jest and move on. I really honestly am
curious about what an instantaneous value of "power" is when reported by
EM. I can't make use of a tool if I don't understand what it's
measuring or reporting. I'm not saying that EM is useless - it is very
accurate on the pace and other readings. And maybe these "power" values
are real. I just don't understand what they are, and would like to.
-KC
Jake
speed you'd go in a viscous medium (water) by dealing with the
acceleration/deceleration of a fan in a viscous medium (air).
More explicitly, I read somewhere it estimates the speed you'd go in a
VIII+ in still water with 7 other identical yous pulling as hard and
with efficient technique and a cox steering.
This is why you can only pull, say, a 1:45 for a few strokes in real
life on the water in a single scull with a speedcoach, but manage it
for several thousand metres on an ergo.
kda...@kidare.com
> This is why you can only pull, say, a 1:45 for a few strokes in real
> life on the water in a single scull with a speedcoach, but manage it
> for several thousand metres on an ergo.
*gulp*
Peter Ford
I can't find a source atm, but my memory of it is that it's
standardised based on a 4- with 90 or 95 kg rowers; so in particular
lightweights pulling 6:30s should be able to go a fair way sub 6:30 on
the water in a 4-
Peter
paul_v...@hotmail.com
Once again, you're very close. M4- 100kg (Rowing Biomechanics
Newsletter has the details on that.) or M4+ 85kg (allowing for minimum
cox weight) I suppose.
Your theoretical LWT's would have about a 5 second advantage over
their Erg Pace in the LM4-. IOW, they could go twice as far in the
boat at the same Pace as they could on the Erg.
Of course this assumes a connection to the water that rivals the chain/
cog interface of the Erg, which may or may not occur due to what
happens at the catch, or "blade entry" for those that don't like the
term "catch". [:o)
- Paul
paul_v...@hotmail.com
Boy I must be lucky?! To have designed something that works, even
though I don't know how or why. If we could all be so fortunate. LOL
Ah, so now it was "in jest", I suppose I can take your word for that,
otherwise it would be logical to conclude you are insane. Attempting
to explain things to insane people is not generally productive.
Anyway, yer so smart, go figure it out for yourself, Anu Dudhia's
pages on The physics of ergometers should be enough, after all that's
where many of the formulas came from. His analysis of Slides Vs
Grounded Erg is completely wrong, but the other stuff seemed to work
out.
As usual, Jab away, since you apparently have no ability to restrain
yourself. Seems you've spent too much time trying to become educated,
how is that working out for you, anything productive come out of it
yet?
- Paul Smith
PS - I was rather successful at selling computers for a number of
years and don't claim to know exactly how they work either. I also
know next to nothing regarding internal ballistics, but that doesn't
apparently effect my marksmanship. (Since Walter may be lurking about,
I recently put 3 consecutive shots in a 0.176" group at 200yd, from a
rifle that I had never known except for those 3 shots. All due credit
to the gunsmith and ammunition assembler, of course. Anyone can pull
a trigger!) LOL
kc
The fact that you often take such statements at face value makes me
question YOUR sanity. Or at least it makes me assume that you might
have some mental disorder like Ashperger Syndrome (characterized by
difficulties with social interaction). Although you apparently lack the
physical clumsiness that usually goes with AS, so If not full-blown,
maybe at least on the marginal Autism spectrum.
> to explain things to insane people is not generally productive.
> Anyway, yer so smart, go figure it out for yourself, Anu Dudhia's
You keep telling me how smart you think I am, yet you never accept
anything I have to say as true, or correct. This is another indication
of borderline mental disorder. Or are you just joking? If you really
do NOT think I'm smart, then you're just cruel to send off someone to
study a physics page whom you don't think has the capacity to understand
it. Either way, your behavior is not indicative of mental soundness.
> pages on The physics of ergometers should be enough, after all that's
> where many of the formulas came from. His analysis of Slides Vs
> Grounded Erg is completely wrong, but the other stuff seemed to work
> out.
So the man with a PhD in physics is spot on when you need/want him to
be, but when his analysis differs from what you, in all your vast
(mis)understanding of physics, think you know, he's "completely wrong".
Precious.
I have looked at the equations for the physics of ergometers, back when
I was trying to use your software for a project. His equations all make
sense. The instantaneous power data coming out of EM doesn't. I'm
guessing that what you or your programmer decided to call "power"
doesn't really have units of power, or if it does the units don't match
(e.g. using instantaneous force with average velocity - units are Watts,
but they are incorrectly calculated and meaningless). Which is fine,
but it would be nice to know what it is. It might be useful, but until
it's defined, those units are useless (again, I'm talking about the
instantaneous units called "power" not the average power per stroke
units which do make sense).
This situation is as if someone gave me a laser range finder with a
display for results, but the results don't have units, and don't seem to
match up with any distance units I'm familiar with. Maybe the display
is really showing the time for the light beam's round trip, which can be
converted to distance. But until the display units are defined, the
device is useless.
> As usual, Jab away, since you apparently have no ability to restrain
> yourself. Seems you've spent too much time trying to become educated,
No jabs here. Just observations.
> how is that working out for you, anything productive come out of it
> yet?
>
> - Paul Smith
>
> PS - I was rather successful at selling computers for a number of
> years and don't claim to know exactly how they work either. I also
> know next to nothing regarding internal ballistics, but that doesn't
> apparently effect my marksmanship. (Since Walter may be lurking about,
You forgot the most apropos example: The fact that you have a few
massive misconceptions about the physics of rowing doesn't apparently
affect (with an a) your skill as a rower (I'm going by your own horn
tooting - I've never seen you row obviously).
Salesmen don't always have to understand every detail of the inner
workings of their products. They often don't. But they can and should
be able to explain all the features, and what they are meant and/or used
for. Or, when they can't explain something a good salesman admits it
(btw, that's done by saying "I don't know") and then goes back to the
designers or engineers who do understand it, gets the information and
brings it back to the customer. Novel concept I know. But it works out
really well for others. You might consider it.
> I recently put 3 consecutive shots in a 0.176" group at 200yd, from a
> rifle that I had never known except for those 3 shots. All due credit
> to the gunsmith and ammunition assembler, of course. Anyone can pull
> a trigger!) LOL
I disagree. Anyone can pull a trigger and achieve what you did IF the
firearm is rigidly mounted to a relatively immobile platform. What you
did requires a lot of fine motor skill and neuromuscular control.
Curious - how do you measure the grouping? I have no idea, but I would
guess you'd report the maximum distance between any two target holes.
Isn't 0.176" less than the caliber of the bullet? If so, how do you
measure that distance? Or were you shooting BBs? :^)
-KC
kc
I recall being told the same or a similar thing at one time. I don't
know if it's true, but it seems to work out fairly well. In college our
scores seemed to match our 4+ speed (most of us were ~90kg excepting of
course the cox!)
-KC
paul_v...@hotmail.com
>
> Curious - how do you measure the grouping? I have no idea, but I would
> guess you'd report the maximum distance between any two target holes.
> Isn't 0.176" less than the caliber of the bullet? If so, how do you
> measure that distance? Or were you shooting BBs? :^)
>
> -KC
It's called a CTC (Center to Center) measurement, calculated by
measuring the extreme boundary edges of the impacts and subtracting
the caliber. i.e. A single hole would be a 0.000" group (well not
really a group, as it was only one shot, but surely you get the
idea.).
Good to see that you know your BB's, almost. (0.177" BTW)
If you are asking about the "Power" unit, under the Spike Data in the
Text Log view, it's the Watts being absorbed by the flywheel at that
given moment. (Of course it says that when the unit is selected,
can't you read?)
As for the rest, just more of the same idiocy I see from you when you
get bent. Bub-bye now....
- Paul Smith
Ted van de Weteringe
> If you are asking about the "Power" unit, under the Spike Data in the
> Text Log view, it's the Watts being absorbed by the flywheel at that
> given moment.
"Watts absorption" (energy dissipation?) is not a meaningful concept for
one given moment. Between two points in time, yes.
KC
> On Oct 8, 9:54 am, kc <kc_n...@sonic.net> wrote:
>> Curious - how do you measure the grouping? I have no idea, but I would
>> guess you'd report the maximum distance between any two target holes.
>> Isn't 0.176" less than the caliber of the bullet? If so, how do you
>> measure that distance? Or were you shooting BBs? :^)
>>
>> -KC
>
> It's called a CTC (Center to Center) measurement, calculated by
> measuring the extreme boundary edges of the impacts and subtracting
> the caliber. i.e. A single hole would be a 0.000" group (well not
> really a group, as it was only one shot, but surely you get the
> idea.).
I guess we can't all be Robin Hood. :^)
(2 shots one hole).
> Good to see that you know your BB's, almost. (0.177" BTW)
Lucky guess. I was just trying to think of the smallest caliber
"bullet" I could think of. Is there something smaller than a BB that
some guns fire/shoot? "Pellets" are the same caliber as BBs right?
> If you are asking about the "Power" unit, under the Spike Data in the
> Text Log view, it's the Watts being absorbed by the flywheel at that
> given moment.
No it isn't. Watts = force on the handle * velocity of the handle, at
any given instant. Take the handle velocity at the same moment, and the
handle force at that moment, and you get the Watts absorbed by the
flywheel at that moment. This is not the number EM reports. Check it
yourself, it's easy enough since EM also reports instantaneous handle
velocity and handle force.
> (Of course it says that when the unit is selected,
> can't you read?)
Yes, which is why I brought this up. Your software says one thing, but
when I do some simple math to check, it doesn't match. So maybe you
need to just change the description of those numbers, as unless I'm
mistaken somewhere, they are not Watts absorbed by the flywheel at that
moment. Maybe have EM say something like "We have no idea what these
numbers are, but maybe you the user might find them interesting."
Saying that they are instantaneous Watts is AFAICT, wrong and misleading.
Alternatively, if you want to make EM report the correct values that
you're trying to report, all you have to do is remove (don't report in
the spike data) the current erroneous "Power" numbers, and just insert a
few lines of code that multiplies handle force * handle velocity at a
given instant in time, and you're golden. I did the same thing in my
own (MATLAB) code when I was using EM's spike data output.
This BTW, is what's called a user bug report. You're the only software
vendor/manufacturer I've EVER come across who's been so opposed to &
closed minded about such a thing. You have, AFAICT, a mistake in your
product, the fix is easy, and yet you have thus far refused to
acknowledge it or even explain it.
> As for the rest, just more of the same idiocy I see from you when you
> get bent. Bub-bye now....
Not 'bent' at all. Perfectly cool, calm, collected, and content.
-KC
KC
Sure it is. It's the time rate of change of the Energy. Surely you've
studied derivatives in 1st year Calculus? If not I apologize. Anyway,
it's just the slope of the Energy-time curve at any instant in time.
It's very meaningful, and can easily be calculated by P=F*V as explained
in my last post to Paul.
-KC
paul_v...@hotmail.com
<myfulln...@xs4all.nl.invalid> wrote:
Thanks for clarifying that. In the USA a "moment" is not an
"instant", it implies an interval of time, in this case the time
between two pulses from the flywheel sensor.
- Paul Smith
Teaplant
wrote:
> paul_v_sm...@hotmail.com wrote:
> > If you are asking about the "Power" unit, under the Spike Data in the
> > Text Log view, it's the Watts being absorbed by the flywheel at that
> > given moment.
>
> "Watts absorption" (energy dissipation?) is not a meaningful concept for
> one given moment. Between two points in time, yes.
Its a crazy phrase of course...but watt (being a unit of power = RATE
of transfer of energy) is correct as an instantaneous concept.
Energy is not - but that was your mistake, not his!
(Of course the monitor is likely to be measuring instantaneous values
of the angular velocity of the wheel and from that updating its value
for the rotational KE over successive small-ish time intervals).
Power = force*velocity this is true for the rate of work done by the
rower on the ergo handle. This is not the same as power = rate of
increase of rotational KE of the wheel, although it ought to be
similar (the latter should be more than the former). For instance
some of the work being done becomes KE of the chain and handle, some
is stored in strain energy of the elastic return cords etc.
While we're at it... watts takes a lower case "w". It's not somebody's
name, it is the unit of power.
See, I can be petty too. I'm not as good as Paul or KC though. Over
to you two...
teaplant.
wmar...@gmail.com
That's good shooting. I'm happy with 3/4 minute vertical dispersion
using nato 5.56 at 600 m prone off elbows with sling support and a 3
pound trigger. Long time since I did that.
Rifle's still good for it, I'm badly out of practice.
W
Ted van de Weteringe
> On 8 Oct, 20:30, Ted van de Weteringe wrote:
>> "Watts absorption" (energy dissipation?) is not a meaningful concept for
>> one given moment. Between two points in time, yes.
>
> Its a crazy phrase of course...but watt (being a unit of power = RATE
> of transfer of energy) is correct as an instantaneous concept.
>
> Energy is not - but that was your mistake, not his!
Sorry, my interpretation error.
Carl Douglas
> On 8 Oct, 20:30, Ted van de Weteringe <myfulln...@xs4all.nl.invalid>
> wrote:
>> paul_v_sm...@hotmail.com wrote:
>>> If you are asking about the "Power" unit, under the Spike Data in the
>>> Text Log view, it's the Watts being absorbed by the flywheel at that
>>> given moment.
>> "Watts absorption" (energy dissipation?) is not a meaningful concept for
>> one given moment. Between two points in time, yes.
>
> Its a crazy phrase of course...but watt (being a unit of power = RATE
> of transfer of energy) is correct as an instantaneous concept.
>
> Energy is not - but that was your mistake, not his!
> (Of course the monitor is likely to be measuring instantaneous values
> of the angular velocity of the wheel and from that updating its value
> for the rotational KE over successive small-ish time intervals).
>
> Power = force*velocity this is true for the rate of work done by the
> rower on the ergo handle. This is not the same as power = rate of
> increase of rotational KE of the wheel, although it ought to be
> similar (the latter should be more than the former). For instance
> some of the work being done becomes KE of the chain and handle, some
> is stored in strain energy of the elastic return cords etc.
Well, let's be picky, shall we?
Instantaneous stroke power = rate of inc. of rotational KE, _plus_ rate
of power dissipation by the fan, plus rate of input of energy into
stretching bungee, plus rate of inc. of body KE as it moves along the slide.
After the finish there's a further dissipation of energy (work to do)
= rate of inc. in bodily KE in moving from stasis towards the catch.
In the short distance before the catch there's a further energy
dissipation term (more work to do)
= rate of decr. in bodily KE to bring the body to a halt before moving
back up the slide.
Neither of those last 2 terms is computed, nor are they avoidable, nor
are they insignificant, nor do they have equivalents in the actual boat.
They constitute parasitic work done by the rower during the erg stroke
that is simply ignored by the erg computation. Try "rowing" up & down
the erg slide without pulling the handle & you'll see what I mean.
Strange that rowing is content to ignore such a term when supposedly
making precise measurements of a rower's work rate.
>
> While we're at it... watts takes a lower case "w". It's not somebody's
> name, it is the unit of power.
> See, I can be petty too. I'm not as good as Paul or KC though. Over
> to you two...
>
> teaplant.
Practice makes perfect.
;)
Carl
--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing Low-drag Riggers/Advanced Accessories
Write: Harris Boatyard, Laleham Reach, Chertsey KT16 8RP, UK
Find: http://tinyurl.com/2tqujf
Email: ca...@carldouglas.co.uk Tel: +44(0)1932-570946 Fax: -563682
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)
paul_v...@hotmail.com
RSR - Rec.Sport.Rifle entry:
That would make me happy too. This was from a bench, but only
mechanical support on the fore end, and a 1lb trigger. The owner
asked "You've done this before?" I replied, "No, that's pretty
unusual." He did let me cut out the target.
http://www.ps-sport.net/pictures/6.5mmGroup_200yd.jpg
I'll be heading to the range tomorrow for some barrel lapping to see
if it helps tighten up my long range gun a bit, otherwise it will be
off to get a new barrel when I can afford it. I fear being spoiled
after not having been to the range for a few years and getting that
result. But at least I got the name of his gunsmith. I'm also
unlikely to go to the extremes of case preparation that he did, which
could well be the difference.
I do have a rifle that shoots like the above, but it's a 10lb hunting
rig and the pet load is at the hot end of the scale; so I keep it for
special occasions and keep trying to get the other one up to snuff.
Are you shooting the 5.56 out of the AR-15/M16 platform, or something
else? I've been impressed by the precision capability of a few AR's,
though it's a tiny pellet at 600m+. I don't have anything with enough
twist for the 75gr bullets so am stuck in the 50-62 range with the
52's working out pretty well.
- Paul Smith
wmar...@gmail.com
> I'll be heading to the range tomorrow for some barrel lapping to see
> if it helps tighten up my long range gun a bit, otherwise it will be
> off to get a new barrel when I can afford it. I fear being spoiled
> after not having been to the range for a few years and getting that
> result. But at least I got the name of his gunsmith. I'm also
> unlikely to go to the extremes of case preparation that he did, which
> could well be the difference.
> I do have a rifle that shoots like the above, but it's a 10lb hunting
> rig and the pet load is at the hot end of the scale; so I keep it for
> special occasions and keep trying to get the other one up to snuff.
>
> Are you shooting the 5.56 out of the AR-15/M16 platform, or something
> else? I've been impressed by the precision capability of a few AR's,
> though it's a tiny pellet at 600m+. I don't have anything with enough
> twist for the 75gr bullets so am stuck in the 50-62 range with the
> 52's working out pretty well.
>
> - Paul Smith
Sportco single shot bolt action. Epoxy-Steel bedded action, Gaillard,
button-rifled, lapped barrel. built 1995, hardly shot 1000 rds.
kc
Well, it is somebody's name, James Watt, who helped develop the steam
engine. However, you're correct that when used as a unit of power, it
should be written 'watt'. However, to add to the confusion, the
abbreviation of watt is large/capital 'W'.
-KC
wmar...@gmail.com
>
> Well, it is somebody's name, James Watt, who helped develop the steam
> engine. However, you're correct that when used as a unit of power, it
> should be written 'watt'. However, to add to the confusion, the
> abbreviation of watt is large/capital 'W'.
>
> -KC
>
Woo hoo!! I wondered if someone would answer that one...
SI units, if I remember correctly, are usually abbreviated with the
capital so
20 litres would be 20 L
20 millilitres would be 20 mL
20 watts - 20 W
20 joules would be 20 J
(and the space between the number and the label is important IIRC -
must look up my little pre-internet SI handbook)
and so on... things you remember from writing a thesis
Cheers,
W
Christopher Kerr
> paul_v...@hotmail.com wrote:
>
>> If you are asking about the "Power" unit, under the Spike Data in the
>> Text Log view, it's the Watts being absorbed by the flywheel at that
>> given moment.
>
> No it isn't. Watts = force on the handle * velocity of the handle, at
> any given instant. Take the handle velocity at the same moment, and the
> handle force at that moment, and you get the Watts absorbed by the
> flywheel at that moment. This is not the number EM reports. Check it
> yourself, it's easy enough since EM also reports instantaneous handle
> velocity and handle force.
>
If I have understood Paul correctly, handle force doesn't come into it,
because EM's not measuring the power being put in by the rower but the
power being dissipated by the flywheel. It's effectively displaying the
rotational speed of the flywheel on a non-linear scale. Trying to show the
instantaneous power input would probably give fairly inaccurate results,
because you're multiplying a second derivative by a first derivative - any
limitations in the resolution of the primary sensor would be magnified
massively.
Rob Collings
> Woo hoo!! I wondered if someone would answer that one...
> SI units, if I remember correctly, are usually abbreviated with the
> capital so
Only where dervied from a name, otherwise they are lowercase. ie watts-
> W but seconds -> s. The litre is an exception (and isn't SI) because
NIST decided that they know best and changed it to a capital so there
are 2 different conventions.
Rob.
Teaplant
>
> Well, let's be picky, shall we?
>
> Instantaneous stroke power = rate of inc. of rotational KE, _plus_ rate
> of power dissipation by the fan, plus rate of input of energy into
> stretching bungee, plus rate of inc. of body KE as it moves along the slide.
>
> After the finish there's a further dissipation of energy (work to do)
> = rate of inc. in bodily KE in moving from stasis towards the catch.
>
> In the short distance before the catch there's a further energy
> dissipation term (more work to do)
> = rate of decr. in bodily KE to bring the body to a halt before moving
> back up the slide.
>
Hey Carl, I felt I was informing the 'debate' between KC and PS about
the difference between KC's power (rate at which rower does work on
the handle = F*v) compared with the way the erg (and perhaps PS's
software) calculates power (rate at which KE is added to the wheel).
As I read it, KC is using the difference in these two quantities to
criticise PS regarding his software and PS is criticising KC for
historical reasons. My point is there is a good reason for the
difference, and continuing to argue about puts at least one of them in
the wrong...
All the other stuff about the difference between ergo performance and
on-water performance is, as ever, true enough but not exactly on-the-
point. All the erg 'cares about' is how much work you do on the
handle, and all it displays is the fraction of that work which is
transferred (temporarily) in the spinning flywheel.
As I see it, the main cause of much of the wrangling over the buoyancy-
or-otherwise of ergometers is the fact that they offer a 500m split
display (plus all the derivatives of it eg distance travelled).
Without this feature, we would probably all be happier about their
role in rowing training - ie as a self-loading simultaneous leg-press
and bench-pull machine with a clock on it. If one only ever set it to
read in watts, I suspect we would use it more sensibly!
Teaplant.
Ted van de Weteringe
> The litre is an exception (and isn't SI) because
> NIST decided that they know best and changed it to a capital so there
> are 2 different conventions.
NIST? It goes even higher than that ;) http://www.bipm.org/fr/CGPM/db/16/6/
Carl Douglas
Don't disagree with any of that.
However, I do find the ability of a sport to believe the incredible a
little depressing. Something like 100 W goes unmeasured, unaccounted
for & ignored, yet pundits hang on the supposed significance of the odd
virtual .1 sec.
No wonder folk say erg technique can be fudged to improve readings.
Let's at least recognised openly that however the power measured,
instantaneous or average I care not, is significantly incorrect & that
the erger does a chunk of work which goes unrecorded & which is no
counterpart in rowing.
Cheers -
Teaplant
> engine. However, you're correct that when used as a unit of power, it
> should be written 'watt'. However, to add to the confusion, the
> abbreviation of watt is large/capital 'W'.
>
> -KC
No, Watt is his name and watt is the unit. The unit is clearly
eponymous (thanks for reminding everyone though) but they are most
certainly not the same thing. There is no confusion since all such
units are written in lower case in full (coulomb, ampere, joule,
kelvin, newton) but then recover a respectful capital when
abbreviated.
litre takes a capital L in abbreviated form not because of the
pioneering work of Professor Litre, but because l looks like 1 and I
(or is it the other way round?).
Another anomaly is the prefix kilo- which is truncated to lower case k
(for example kg) to avoid confusion with K for kelvin. All other
prefixes for large multiples are upper case, with the small multiples
lower case (cm, Mbyte, ns etc)
However, 100 watts most certainly does not mean 100 members of the
Watt family (unlike 100 Watts).
argh
teaplant.
kc
Indeed, milliliters is usually ml, not mL. Not sure which is correct
off hand...
-KC
kc
>> Well, it is somebody's name, James Watt, who helped develop the steam
>> engine. However, you're correct that when used as a unit of power, it
>> should be written 'watt'. However, to add to the confusion, the
>> abbreviation of watt is large/capital 'W'.
>>
>> -KC
>
> No, Watt is his name and watt is the unit. The unit is clearly
> eponymous (thanks for reminding everyone though) but they are most
> certainly not the same thing. There is no confusion since all such
> units are written in lower case in full (coulomb, ampere, joule,
> kelvin, newton) but then recover a respectful capital when
> abbreviated.
Uhhh... pretty much exactly what I just said above?? So why did your
paragraph start with "No"? I said his name was Watt, and I said the
unit was 'watt', and that the abbreviation is 'W'. To quote Abbot,
"same as you, SAME AS YOU!!!!" :^)
-KC
>
> litre takes a capital L in abbreviated form not because of the
> pioneering work of Professor Litre, but because l looks like 1 and I
> (or is it the other way round?).
>
> Another anomaly is the prefix kilo- which is truncated to lower case k
> (for example kg) to avoid confusion with K for kelvin. All other
> prefixes for large multiples are upper case, with the small multiples
> lower case (cm, Mbyte, ns etc)
>
> However, 100 watts most certainly does not mean 100 members of the
> Watt family (unlike 100 Watts).
>
> argh
??? Dude, we're in agreement. Go have a cup o' tea and plant a tree.
> teaplant.
>
>
kc
Before anyone gets too detailed in their theories here, he/she ought to
go try out EM. Paul will (at least used to) give you a free license to
try it for a week or month or something like that. Then you can see
what it's all about (presuming you can get your erg next to a pc of some
sort... he had issues with some laptops back when I was doing it, but I
think he's worked that out...) All you need is a mini-jack audio cable
from the erg to the PC's sound card, and an adapter for erg wire to
audio wire connection, available from electronics supply stores like
Radio Shack in the States.
EM does not and can not measure force on the handle. It calculates it
based on the delta omega of the flywheel, and the flywheel's inertial
properties. It comes quite close to reality though. I hooked up a
strain gauge and measured force and the two were close. I think the
only difference was attributable to the bungee tension. I also rigged
up a pulley system and dropped weights of known mass, pulling on the
ergo chain, and the force reported by EM was the weight of the mass
minus the bungee tension plus or minus a bit. This was tough to do
given the delay EM has (had?) before registering any values on the first
stroke.
So given that the calculated force is pretty close to reality, and
Newton's third law applies, the instantaneous power must equal the force
reported by EM multiplied by the handle velocity reported by EM (also
checked & verified by me to be "pretty close" to reality. I don't have
the exact data any more.) Heck it must equal this not only because of
Newton's 3rd, but mainly since those values must be derived from the
power in the first place! Anyway, there's no other definition of
"instantaneous power" that I can think of. Also, the curve should go
negative on the recovery since the flywheel is loosing power then, and,
IIRC it doesn't (this part I'm not sure about though, it's been a while
since I toyed with EM).
It's very likely that I've totally misunderstood what the numbers EM
reports are supposed to be, and I'm in the wrong. But until someone can
explain it to me, I'm confident in what I've said. So if you disagree,
please explain it to me. I'm not out to insult Paul. I just want to
understand what those units are, and if I've made a mistake.
-KC
wmar...@gmail.com
Ok so I was off a bit in some of my units.. mea culpa.
http://ess.nrcan.gc.ca/pubs/scipub/guide/abbrev/listgen_e.php
is the result of googling "systeme internationale canada" - an
alphabetic listing of abbreviations expected in scientific
publications according to the Govt of Canukistan..
If I ever prep anything for sci-pub again, I won't try to go from
memory... Why remember stuff you can look up?
W
KC
> Why remember stuff you can look up?
I love it.
That oughtta be the motto for a school of engineering somewhere. We
need a Latin translation!!! ;^)
-KC
paul_v...@hotmail.com
"Quare memor effercio vos can intueor?"
I have no idea how the Power (watts) could go negative, it can go to
zero when stationary, but if it's rotating, it's dissipating energy
and that is what is being expressed in the plot.
- Paul Smith
KC
If the wheel is accelerating, net power flow is positive. If the wheel
is decelerating, net power flow is negative.
-KC
Chris Kerr
"Some people called Romanes they go the 'ouse"?
How about:
"Libre inscriptum, non memorandum"
"When something is written in a book, you don't need to remember it"
paul_v...@hotmail.com
No Kidding? So "Power" and "Net Power" are the same thing?! My
Goodness! I had even typed a sentence regarding the absence of a "Net
Power" plot (then figured it was not needed.), though we do have a Net
Torque plot that will go below the X axis once the applied force is no
longer capable of accelerating the flywheel; IOW, when applied torque
<= Drag torque on the axle. More magic. [:o)
Rec.Sport.Rifle entry: (gotta keep this interesting for myself
somehow.)
The barrel lapping when very well, each 10 round string improved in
consistency with outliers explained by my errors mostly. Of course
there was no particular care put into assembling the ammo being used
as would normally be the case (hence the "mostly"). In the end I went
back to the Standard Load that the rifle favors, fired 3 rounds to
determine the new POI, made the required adjustment and fired a single
"proof" round for confirmation and viola, as close to dead center as
could be expected. Very pleased with the result. Also, the "younger
twin" rifle (.22LR) proved to be most excellent at 100yd, the best
part was that the bullet could actually be watched through the scope
on it's travel downrange, and at $0.02/round it's much more affordable
to shoot, while simulating much longer ranges for the high power
rifle. Practice, practice, practice....
- Paul Smith
wmar...@gmail.com
Hmm. I rephrased something Einstein is supposed to have said, and he
prolly wasn't the first.
W
KC
> On Oct 9, 10:51 pm, KC <kc_n...@sonic.net> wrote:
>> paul_v_sm...@hotmail.com wrote:
>>> On Oct 9, 12:51 pm, KC <kc_n...@sonic.net> wrote:
>>>> wmart...@gmail.com wrote:
>>>>> Why remember stuff you can look up?
>>>> I love it.
>>>> That oughtta be the motto for a school of engineering somewhere. We
>>>> need a Latin translation!!! ;^)
>>>> -KC
>>> "Quare memor effercio vos can intueor?"
>>> I have no idea how the Power (watts) could go negative, it can go to
>>> zero when stationary, but if it's rotating, it's dissipating energy
>>> and that is what is being expressed in the plot.
>>> - Paul Smith
>> If the wheel is accelerating, net power flow is positive. If the wheel
>> is decelerating, net power flow is negative.
>>
>> -KC
>
> No Kidding? So "Power" and "Net Power" are the same thing?! My
I don't follow you here, between what you write, and then your implied
sarcasm, I'm not sure if you actually agree or disagree with the
statement you just made.
> Goodness! I had even typed a sentence regarding the absence of a "Net
> Power" plot (then figured it was not needed.), though we do have a Net
> Torque plot that will go below the X axis once the applied force is no
> longer capable of accelerating the flywheel; IOW, when applied torque
> <= Drag torque on the axle. More magic. [:o)
You have stated that the instantaneous power values EM reports in the
spike data are the power dissipated by the ergo. While I doubt that's
actually the case, even if it is correct it's quite a useless thing to
report. A rower cares about the power he/she is supplying (either
instantaneous or averaged over a storke). The power the rower supplies
has two parts, power from viscous forces on the flywheel, and power from
inertial forces of the flywheel. So,
P_rower = P_viscous + P_inertia
If all EM reports is the dissipated power, then that's only P_viscous,
and ignores the inertial effects. (BTW in P_visc, I'm grouping power to
pump air, and drag-power from bearing and aero friction). So reporting
only the dissipated power is pretty meaningless to a rower, except maybe
during the recovery when P_rower is zero and P_visc = -P_inert.
> Rec.Sport.Rifle entry: (gotta keep this interesting for myself
> somehow.)
Here is a group of people who probably care:
http://groups.google.com/group/rec.guns/topics?lnk
-KC
Carl Douglas
< snipped >
>
> However, I do find the ability of a sport to believe the incredible a
> little depressing. Something like 100 W goes unmeasured, unaccounted
> for & ignored, yet pundits hang on the supposed significance of the odd
> virtual .1 sec.
>
> No wonder folk say erg technique can be fudged to improve readings.
> Let's at least recognised openly that however the power measured,
> instantaneous or average I care not, is significantly incorrect & that
> the erger does a chunk of work which goes unrecorded & which is no
> counterpart in rowing.
>
> Cheers -
> Carl
>
I was surprised that my posting, above, generated not even a whisper of
a response from RSR's erg-warriors.
Doesn't it matter to them that >100W, typically, of the erger's average
work rate goes unmeasured?
Why are they, when claiming that ergs accurately measure the work done,
content to turn so blind an eye to this inconvenient elephant leaving
his mark in a corner of their room?
kda...@kidare.com
> URLs: www.carldouglas.co.uk(boats) &www.aerowing.co.uk(riggers)
I was contemplating it. My hand is forced...
I recently tried putting some industrial-sized fixed castors on the
bottom of my model C to see what effect it would have on my technique
and scores. The thing I noticed immediately was the change around the
catch. I had to consciously draw the erg up under me whereas on a
fixed erg I could let myself roll up into the catch under my own
moment. I think this difference has 2 consequences:
1. On a sliding erg/boat, the stroke is shorter in length than on a
fixed erg since the body has no momentum going into the catch. This
resulted in worse splits than on a fixed erg.
2. On a fixed erg, the extra length produces more tension in the knees
and ankles which act as springs and help mitigate the extra effort
required to change momentum at the catch.
So at lower rates (= lower momentum) I am not sure that the difference
in required effort is that great.
At higher rates, things work much more in favour of the sliding erg. I
could rate 40 no problem with corresponding improvement in splits.
These are just my impressions. Nothing scientific.
Kit
paul_v...@hotmail.com
> Carl Douglas wrote:
>
> < snipped >
>
>
>
> > However, I do find the ability of a sport to believe the incredible a
> > little depressing. Something like 100 W goes unmeasured, unaccounted
> > for & ignored, yet pundits hang on the supposed significance of the odd
> > virtual .1 sec.
>
> > No wonder folk say erg technique can be fudged to improve readings.
> > Let's at least recognised openly that however the power measured,
> > instantaneous or average I care not, is significantly incorrect & that
> > the erger does a chunk of work which goes unrecorded & which is no
> > counterpart in rowing.
>
> > Cheers -
> > Carl
>
> I was surprised that my posting, above, generated not even a whisper of
> a response from RSR's erg-warriors.
>
> Doesn't it matter to them that >100W, typically, of the erger's average
> work rate goes unmeasured?
>
> Why are they, when claiming that ergs accurately measure the work done,
> content to turn so blind an eye to this inconvenient elephant leaving
> his mark in a corner of their room?
>
> Cheers -
> Carl
>
Perhaps because it's nothing "like 100 watts" that goes unaccounted
for, and we've been down this road (Slide) before. One way or the
other, the system is in equilibrium with the flywheel dissipating the
vast majority (should be "all") the input energy from the rower. I
suppose there could be a good bit being absorbed by the ground/rubber
foot interface for those that use the straps to arrest the body
momentum at the finish, but that's a bad technical flaw which should
be corrected.
On slides, it's easy to see, as we can know just what distance the
seat should move, WRT the ground, based on the Mass of the Erg Vs Mass
of the Rower, anything outside of that would indeed have a counterpart
in a boat, and none of it would be good.
I had a rower get quite snippy recently when they asked "So you want
us to bring the rate up by getting the blade faster through the water,
right?", to which I answered "No, why would I want you to shorten your
drive like that? You can't do anything to accelerate the system
toward the finish line unless your blade is in the water, so if you
shorten that time you will lose the benefit of increasing the rate."
Though, based on observations, it would appear that one may be able to
reduce the physical length of the drive while maintaining the temporal
length as the rate comes up, along with a corresponding increase in
Avg system speed.
Kit had some rather insightful things to offer on the subject, though
his statement about being able to "rate 40 no problem with a
corresponding drop in pace" is not quite accurate, or I suppose that
he could do a 2k on slides R40 and set a new PR "no problem", but that
hasn't happened yet for anyone with a consistent performance record
for the standard 2k test. All Ergs are "dynamic", they simply vary in
the magnitude of visible dynamism. [;o)
- Paul Smith
kda...@kidare.com
> Kit had some rather insightful things to offer on the subject, though
> his statement about being able to "rate 40 no problem with a
> corresponding drop in pace" is not quite accurate, or I suppose that
> he could do a 2k on slides R40 and set a new PR "no problem", but that
> hasn't happened yet for anyone with a consistent performance record
> for the standard 2k test. All Ergs are "dynamic", they simply vary in
> the magnitude of visible dynamism. [;o)
>
> - Paul Smith
Hey, don't bring me into it!
To clarify, there is no way I could rate 40 on a static erg, but it
(and higher) is "no problem" on a dynamic one.
The splits produced at this rate were comparative to what I might
produce at eg rate 28 on a static erg, maybe a little bit better. This
is the real reason why I wanted to do the experiment as at 28 on a
static erg, I find my technique is so un-boat-like as to be harmful.
On a dynamic erg, I can do long pieces at 26-28 and work alot closer
to how I would in a boat, albeit with worse splits. I don't tend to
compare my splits with others so their absolute value doesn't concern
me. So long as it works me hard and is closer to my boat technique.
Kit
freeheelfunhog
be fudged to improve readings."
Teesbees
On Oct 22, 10:33 am, Carl Douglas <c...@carldouglas.co.uk> wrote:
> Email: c...@carldouglas.co.uk Tel: +44(0)1932-570946 Fax: -563682
> URLs: www.carldouglas.co.uk(boats) &www.aerowing.co.uk(riggers)
KC
> Carl Douglas wrote:
> < snipped >
>>
>> However, I do find the ability of a sport to believe the incredible a
>> little depressing. Something like 100 W goes unmeasured, unaccounted
>> for & ignored, yet pundits hang on the supposed significance of the
>> odd virtual .1 sec.
>>
>> No wonder folk say erg technique can be fudged to improve readings.
>> Let's at least recognised openly that however the power measured,
>> instantaneous or average I care not, is significantly incorrect & that
>> the erger does a chunk of work which goes unrecorded & which is no
>> counterpart in rowing.
>>
>> Cheers -
>> Carl
>>
>
> I was surprised that my posting, above, generated not even a whisper of
> a response from RSR's erg-warriors.
>
> Doesn't it matter to them that >100W, typically, of the erger's average
> work rate goes unmeasured?
>
> Why are they, when claiming that ergs accurately measure the work done,
> content to turn so blind an eye to this inconvenient elephant leaving
> his mark in a corner of their room?
>
> Cheers -
> Carl
>
I guess I don't see the big deal. It's a tool for conditioning and
testing of fitness. It is not and should not be an indication of actual
boat speed. I was never one who had to stand behind the mantra "ergs
don't float" but it has much truth to it.
If the erg doesn't account for ~100W, so long as it's consistent from
rower-to-rower, then so what? When I do squats in the gym, I don't
complain to the coach that the short guys have less work ( =F*d) to do.
Or that the mass moment of inertia of my longer bones means I expend
more energy just extending my legs than the shorter guys. You either put
up Xlb of weight or you don't. In the end your skill on the water is
all that counts.
Is .1 seconds on an erg important? Sure if you're racing indoors. But
when it comes to making boating assignments, of course it's negligible.
Your comments though, are a good example of why scores from a static erg
and a dynamic erg (erg on slides, etc.) should not be compared. Much of
the unmeasured 100W you describe goes away when the rower doesn't have
to redirect nearly as much of his/her body mass twice per stroke, and
some of that otherwise wasted (unmeasured) energy can go into moving the
flywheel.
-Kieran
-KC
KC
> An aspiring erg-warrior, I would like to know how "erg technique can
> be fudged to improve readings."
>
> Teesbees
>
As described earlier in this thread, if you can get strong and
comfortable with a very exaggerated length to your drive (extra long at
the catch, very extra long at the finish - pull the chain to your chin
as you lay way back) then you can do a lot more work per stroke. This
technique is not easy to do, so takes practice, and is nearly useless on
the water.
-KC
MagnusBurbanks
> If the erg doesn't account for ~100W, so long as it's consistent from
> all that counts. ...... But when it comes to making boating assignments, of course it's negligible.
If only that were true. It's a sad sad fact of British rowing that
it's very common for enormous weight to be placed on erg scores and
very little on water-based performances, be they seat-racing or single
sculling.
kc
That's true here too (here=USA). I didn't say it was uncommon, just
that it shouldn't be. But any coach who boats one guy over another just
because of a .1 sec difference in an erg score should be fired.
-KC
Charles Carroll
Speaking of what erg scores have to do with boat selection, what follows is
an account Boat Selection from Mark de Rond's "The Last Amateurs." I thought
you might find it interesting, especially in light of your strong advocacy
in the past for "science." It begins with a young man named Colin Scott.
Colin thought he had a seat in the Blue Boat, and then learns he doesn't. He
has just left a meeting with the coaches in which he has been told that he
no longer has a seat.
"When [Colin] reappears, his face betrays the anguish inside. His eyes are
strained, his skin pale and drawn, his hands trembling involuntarily, his
mind fogged up with bewilderment. Having won his seat-race, having
registered impressive numbers on the erg tests, having bloody well met all
objective criteria, how is he to satisfy those that are subjective? Those
that depend on visual impressions from coaching launches? On their intuition
and gut feeling? On similarities drawn with past Boat Race crews, sometimes
in the very distant past? In fact, it's quite striking to see the extent to
which coaches rely on subjective judgments in making decisions. These
judgment don't usually override objective assessments of performance, but
they help coaches to differentiate between oarsmen who are on paper
virtually identical; or if not identical, very close; or if not close, then
prone to generating results that confuse. Such happens when you beat another
oarsman in seat-racing who himself has just beaten someone who now beats
you.
"Selection, of course, is never based on a single criterion but instead
relies on a combination of hard and soft data, on erg scores and visuals, on
seat-racing and gut feel, on current performance and memories of past
performance. To paraphrase 'Financial Times' columnist John Kay, the
attractiveness of a face, the happiness of a society, the progress of a
civilization, the potential of a rowing crew, is multi-dimensional;
components of attractiveness, happiness, progress or potential are
determined by subjective consensus and are not always susceptible to
objective measurement. It is thus somewhat surprising, he says, that
scientists and wannabe scientists such as economists resist the use of soft
data. He quotes Lord Kelvin as having suggested that unless you can measure
something your knowledge is of a meagre kind. But of course Kelvin also
suggested that manned space flight was impossible. Complex activities, like
sweep rowing, can only be described with words, says Kay, using a
combination of hard and soft data - hard data being supplements, not
substitutes for the evidence provided by eyes, guts and ear."
It is the sort of passage that makes one wonder why anyone in their right
mind would want to be a coach.
Cordially,
Charles
KC
> Kieran,
>
>
> It is the sort of passage that makes one wonder why anyone in their
> right mind would want to be a coach.
Indeed. All of which supports my general dislike for seat racing (as a
coach and an athlete.) I never lost a seat race myself, although there
were ports whom I never had to race who might have given me a run for my
money, and after my sophomore year my seat was never challenged. But
even still I was never convinced that it was a valid way of determining
lineups. There are too many variables to really control. The best you
can do with seat racing is, IMO, to gain that much more
subjective/qualitative/gut-feeling data. The results of most seat races
are of meager usefulness at best, and at worst totally obfuscating.
Erg scores and seat races can for the extreme ends of the spectrum serve
as easy tests to exclude certain individuals. But for those rowers who
hover on the borderline, especially when there are several of them, it
can be quite challenging to work out who should be in and who should be
out. If you keep track of the lineups of some of the top college squads
throughout a season, you'll see it often changes EVERY race. In fact,
if it doesn't it might be a bad sign for the program - no depth or
favoritism, etc.
-KC
wmar...@gmail.com
Ah seat racing. Some people feel that you can't do it in pairs and
you have to do some made up comparisons between people by switching
them from four-to-four. But what of the 6 other guys who aren't being
compared? Say one of THEM gives up the ghost, or crabs a few times,
or simply prefers racing with one or the other of the candidates in
spite of that person's opponent being truly faster? Hmm. LOTS of
variables.
Some people feel that a pair matrix is the best way - race a bunch of
pairs until everyone rowing one side has raced with everyone rowing
the other side - keep track of time, and keep the top four pairs (if
you're picking an 8+) - or pick the top four guys on one side and the
top four guys on the other side...
Some people feel that seat racing is best done in time trial format,
others feel it's best done side-by-side.
Personally - and if I were king this is how it would be done....
Initial rank-ordering on the ergometer. Divide the group into pools
(if there are fewer boats than there are pairs of rowers). The faster
(on the erg) pool does an all possible combinations, pairs, time-trial
format series of races. Over the (n) races, each P and each S
accumulates time each race - add them up, rank order the pool
according to total accumulated time, and give the top one or two on
each side in that pool the word that they're selected... their rank
order post seat racing may differ from the ergometer ranking, but
you're on the water now, and the ergs don't matter any more. Then
race the next pool of athletes the same way...This will find the best
of the weaker half of the group, which then race in a third series of
races against the bottom ranked people from the top half of the
group. People will sometimes shift a position or two in the boats
from their ergometer rank order, possibly more if the ranking on the
ergs is very close, but this to me seems about the fairest way to do
it.
Oh - AFTER the seat racing is done, show EVERYONE in the group all of
the results, so the people who were cut can see that it was because
they weren't fast enough, and the people who made it, can believe that
everyone in the boat deserves to bet there...
Some caveats - you need to have pairs from the same maker, all rigged
the same. Same make, length, pitch, rig of oars, too.
Time trial format - you don't need more than one lane, a start timer,
a finish timer, and a safety boat. Side-by-side format you need more
lanes, an umpire in a boat, a safety launch, a start timer, and a
finish timer - guess which I prefer (again)...
W
Carl Douglas
OK, let me give you some numbers, with a little bit of maths attached:
1. Assumptions:
a) Rower mass = 85 kg
b) Distance moved by rower's CG on recovery = 0.6 m
c) Peak velocity of rower's CG on recovery = 1.6 x mean
d) Power stroke duration = 0.8 s
e) Acceleration due to gravity = 9.81 m/s^2
2. Now the maths, for rate =40/min:
Cycle time = 60/40 = 1.5 s
Recovery time = 1.5 - 0.8 = 0.7 s
Avge recovery velocity = 0.6/0.7 = 0.86 m/s
Peak recovery velocity = 0.86 x 1.6 = 1.37 m/s
Kinetic energy gained = 1.37^2 x 85/(2 x 9.81) = 8.15 kgf.m
but Kinetic energy to be dissipated is identical = 8.15 kgf.m
Work done during recovery = 2 x 8.15 x 9.81 = 159.9 J
Average recovery work rate = 159.9/1.5 = 106.6 W
I'd respectfully suggest that my calculated figure here of 106.6 W as
the work rate required to make the recovery (consumed by bodily
acceleration + deceleration) on the fixed erg, but unrecorded by the
monitor, is very much "like 100 watts". Which is what I'd originally
suggested. QED.
Here's a table showing the recovery work rate (time averaged through the
whole stroke) against rating:
Rate Averaged recovery
Strokes/min work rate in Watts
20 5.4
25 12.8
30 27.2
35 54.7
40 106.6
45 206.6
While I'm sure we can fiddle with the numbers. For instance, I assumed
a constant power stroke duration, not allowing for increased measured
"boat" speed with increased work rate (if we assume that work rate does
rise with stroke rate). And I assumed a particular values for CG
movement & for peak recovery speed as a proportion of the mean. But I'd
suggest that the overall picture will stay much the same.
Comments, please.
Pete
Nothing's perfect.
Ergos select for physiology (but you lose if your strength is
technique).
Pairs matrix selects for adaptability and pairs rowing (but you lose
if you take a week to fit into a boat well).
Fours or eights seat racing allows for fixed results (cheese sandwich
beats man can happen..) and seat racing specialists (stay calm while
everyone around you kills themselves in case the first seat race is
theirs, then step it up when you're swapped, push the rating up and
when you're swapped out the boat you left will struggle to hit rate).
Singles ranking selects for single sculling ability (but you can move
a single fast and still be a handbrake in a crew).
All of which are in some way not really the point, compared to ability
to be part of a long term fixed crew rowing an eight, four or quad.
You can always argue. But usually there are six of the eight people
who are clearly in the boat on any measure, and frankly you can select
any two of the nearly-men, it won't make that much difference to boat
speed. They're all going to be decent.
Pete
Carl Douglas
> paul_v...@hotmail.com wrote:
>> On Oct 22, 10:33 am, Carl Douglas <c...@carldouglas.co.uk> wrote:
>>> Carl Douglas wrote:
<snipped>
>>
I hope the following will add some further insights:
The chosen recovery-speed profile clearly affects the amount of kinetic
energy that the fixed erger must first generate & then dissipate between
finish & catch. For rate = 40/min, the model gives:
Ratio of peak to Averaged recovery
mean recovery speed work rate (W)
1.2 60.0
1.4 81.6
1.6 106.6
1.8 134.9
2.0 166.5
Stroke length equally affects recovery length. If we take the 1.6
peak/mean recovery speed ratio, then:
Distance moved by Averaged recovery
Rower's CG (m) work rate (W)
0.4 47.4
0.5 74.0
0.6 106.6
0.7 145.1
0.8 189.5
(Here I should note that I'm not proposing that the rower works harder
on the power stroke, but keeps the same monitor reading. That is
simplistic, but still informative)
Or maybe we could change the duration of the power stroke for the same
median conditions as before:
Power Stroke Averaged recovery
Duration (min) work rate (W)
0.70 81.6
0.75 92.8
0.80 106.6
0.85 123.6
0.90 145.1
I would suggest that these are insights, but that care should be taken
in their interpretation. So no tub-thumping instant deductions, eh?
kc
Carl,
Excellent analysis. I agree with your point overall - that there is a
lot of power required of the rower on the recovery that goes unmeasured
- but I would like to mention another few minor points to consider:
1.) The total mass of the rower is not accelerated and stopped every
stroke. I don't know what a safe approximation would be, but since the
legs move less than the thighs, which move less than the HAT (head arms
trunk), something around 80 to 90% maybe? I can give you some
anthropometric data if you're interested. There's the rotational energy
that the limbs go through as well, although that is often neglected even
in biomechanics analysis (gait, not sports), so is probably safe to
neglect here too.
2.) I know of no hwt male rower who regularly does erg pieces at a
steady rate of anywhere near 40spm on a static erg. Of course your
analysis shows the reason why: it's too taxing. When you only have
400-500W at your disposal for a 6 minute test, wasting 50-70W is not
worth it. Even a short sprint at the end of a piece rarely goes over
35spm in my experience, and the body of the piece is often around
28~30spm (again for hwt men, which your 85kg tbm implies.)
3.) I don't think you accounted for the work done by the bungee cord
attached to the chain. I think a new erg has an average bungee tension
on the order of 6lbf. Paul may remember the exact value(s). Anyway,
the rower has to overcome that force on the drive, so in the end it may
be safe to ignore on the recover, for it's not measured/included in the
drive power calculations (on a C2) either.
As Paul pointed out, we've been down this road before. I tried to
convince him that the hamstrings were used significantly on the
recovery, and IIRC, his argument was that the slope of the seat track
combined with the bungee tension is enough such that the rower does
nearly no work on the recovery. Despite the fact that I have EMG data
showing the hamstrings of several college rowers engaging during the
recovery, I even did a quick experiment by sitting on the seat while
holding the handle (feet held up in the air), and timing how fast the
seat could complete the recovery distance, under gravity alone. IIRC, it
was somewhere around a time that would result in a SR of about 20 or so.
I also pointed out that the hamstrings have to engage even at such low
rates, just to allow the knees to bend, as the weight of the legs and
thighs is enough to cause a knee extension moment greater than the
flexion moment due to gravity acting on the HAT.
I wonder if your analysis will get further with him than my data and
experiments did.
-KC
KC
Yes, the flywheel does dissipate nearly all the energy put into it by
the rower. But Carl was not talking about energy put into the flywheel
by the rower. He's talking about energy expended by the rower that has
no effect on the flywheel.
> suppose there could be a good bit being absorbed by the ground/rubber
> foot interface for those that use the straps to arrest the body
> momentum at the finish, but that's a bad technical flaw which should
> be corrected.
I don't suppose you'll bother to do this, but if you're up for it, I'd
like to know at what rate you can do sustained rowing on a "static" c2
erg if you were to completely remove the foot-strap/heel support
assembly. I mean take the whole plastic part off, and the strap, so
that all you can do is push on the black metal plate without anything
holding your foot to the erg. Friction should be enough on the drive to
keep your feet stationary wrt the erg, but without anything touching
your shoes, the recovery might be more challenging than erging with only
the straps removed.
Caveat: I'm not looking at an erg as I type this, so I'm not even sure
if it's possible to remove the foot stretcher stuff, and if it is, if
there's a good platform left to push on.
-KC
Carl Douglas
I deliberately selected a rather short distance (~23" in your units,
60cm in ours) for the distance moved by the CG, to compensate for bits
of you that move less while not claiming much credit for the bits (waist
upwards) which move a whole lot more. Since the bits that move more
have a disproportionately greater KE per unit mass than those which move
correspondingly less, that ought to be a fair 1st-order approximation.
The arms, of course, & especially the hands, move more than all the rest
&, since we are dealing in non-linear terms, have a greater consequence
on the erg than they would in a boat.
I'm going to guess that rotational effects might be discounted as they
would, I suppose, not change greatly between boat & erg?
> 2.) I know of no hwt male rower who regularly does erg pieces at a
> steady rate of anywhere near 40spm on a static erg. Of course your
> analysis shows the reason why: it's too taxing. When you only have
> 400-500W at your disposal for a 6 minute test, wasting 50-70W is not
> worth it. Even a short sprint at the end of a piece rarely goes over
> 35spm in my experience, and the body of the piece is often around
> 28~30spm (again for hwt men, which your 85kg tbm implies.)
Do we now have a better understanding of why that is?
> 3.) I don't think you accounted for the work done by the bungee cord
> attached to the chain. I think a new erg has an average bungee tension
> on the order of 6lbf. Paul may remember the exact value(s). Anyway,
> the rower has to overcome that force on the drive, so in the end it may
> be safe to ignore on the recover, for it's not measured/included in the
> drive power calculations (on a C2) either.
Correct. I ignored the cord tension.
>
> As Paul pointed out, we've been down this road before. I tried to
> convince him that the hamstrings were used significantly on the
> recovery, and IIRC, his argument was that the slope of the seat track
> combined with the bungee tension is enough such that the rower does
> nearly no work on the recovery.
I think that must be incorrect. In the past I've shown by resolving the
triangle of forces that slide slope is quite inadequate to "get you to
the catch on time". A 6lbf pull on a 187lb mass rower will impart an
acceleration of only 0.032 x g, = 1 ft/s^2 or 0.305 m/s^2, you have ~1
second to reach the catch, but under that acceleration your mass can
travel only 6" or 15cm in that time. So I think the legs do have to
pull, & quite a bit.
Despite the fact that I have EMG data
> showing the hamstrings of several college rowers engaging during the
> recovery, I even did a quick experiment by sitting on the seat while
> holding the handle (feet held up in the air), and timing how fast the
> seat could complete the recovery distance, under gravity alone. IIRC, it
> was somewhere around a time that would result in a SR of about 20 or so.
> I also pointed out that the hamstrings have to engage even at such low
> rates, just to allow the knees to bend, as the weight of the legs and
> thighs is enough to cause a knee extension moment greater than the
> flexion moment due to gravity acting on the HAT.
>
> I wonder if your analysis will get further with him than my data and
> experiments did.
>
> -KC
I'm not out to win arguments but to try inform & to provide extra food
for thought. I can see why it's hard to accept that ergs, the standard
off-water training tool after all, could ignore such a large element of
the rower's total work rate. I hope my analysis of the recovery may
help to clear the air & add perspective to discussions of erg
measurement accuracy.
We might also take a squint at the consequences of work done on body
accelerations on a fixed erg during the power stroke, & how this may
skew the stroke force distribution that the machine will measure. It
shouldn't be too hard to do. Any volunteers?
KC
But since the arms weigh so much less, it's probably as you said, a fair
first order approximation.
> I'm going to guess that rotational effects might be discounted as they
> would, I suppose, not change greatly between boat & erg?
Agreed. They'd be different between boat and erg, but not by much.
>> 2.) I know of no hwt male rower who regularly does erg pieces at a
>> steady rate of anywhere near 40spm on a static erg. Of course your
>> analysis shows the reason why: it's too taxing. When you only have
>> 400-500W at your disposal for a 6 minute test, wasting 50-70W is not
>> worth it. Even a short sprint at the end of a piece rarely goes over
>> 35spm in my experience, and the body of the piece is often around
>> 28~30spm (again for hwt men, which your 85kg tbm implies.)
>
> Do we now have a better understanding of why that is?
No, I already understood why that is, my understanding is no better.
Hopefully someone else's may be. What I'm questioning is that your
analysis relies on a SR=40 to get your ~100W of unmeasured power. I was
just pointing out that no one I know of ever ergs at a rate of 40spm, so
to say that ">100W, typically, of the erger's average work rate goes
unmeasured" is misleading. So, if you want to talk about 100 wasted
watts, and stick to your analysis, then you should rephrase your
statement that I quoted just there, especially the "typically" part.
Your analysis seemed to have been prompted by Paul's claim that "it's
nothing 'like 100 watts' that goes unaccounted for". If you're trying
to defend your claim, which by your wording you certainly seemed to do,
you fell a little short. But the analysis was still very informative.
>> 3.) I don't think you accounted for the work done by the bungee cord
>> attached to the chain. I think a new erg has an average bungee
>> tension on the order of 6lbf. Paul may remember the exact value(s).
>> Anyway, the rower has to overcome that force on the drive, so in the
>> end it may be safe to ignore on the recover, for it's not
>> measured/included in the drive power calculations (on a C2) either.
>
> Correct. I ignored the cord tension.
Why? It's easy enough to add in.
>>
>> As Paul pointed out, we've been down this road before. I tried to
>> convince him that the hamstrings were used significantly on the
>> recovery, and IIRC, his argument was that the slope of the seat track
>> combined with the bungee tension is enough such that the rower does
>> nearly no work on the recovery.
>
> I think that must be incorrect. In the past I've shown by resolving the
> triangle of forces that slide slope is quite inadequate to "get you to
> the catch on time". A 6lbf pull on a 187lb mass rower will impart an
> acceleration of only 0.032 x g, = 1 ft/s^2 or 0.305 m/s^2, you have ~1
> second to reach the catch, but under that acceleration your mass can
> travel only 6" or 15cm in that time. So I think the legs do have to
> pull, & quite a bit.
Agreed.
> Despite the fact that I have EMG data
>> showing the hamstrings of several college rowers engaging during the
>> recovery, I even did a quick experiment by sitting on the seat while
>> holding the handle (feet held up in the air), and timing how fast the
>> seat could complete the recovery distance, under gravity alone. IIRC,
>> it was somewhere around a time that would result in a SR of about 20
>> or so. I also pointed out that the hamstrings have to engage even at
>> such low rates, just to allow the knees to bend, as the weight of the
>> legs and thighs is enough to cause a knee extension moment greater
>> than the flexion moment due to gravity acting on the HAT.
>>
>> I wonder if your analysis will get further with him than my data and
>> experiments did.
>>
>> -KC
>
> I'm not out to win arguments but to try inform & to provide extra food
Nasty little implication you made there (intentional or not). I'm not
out to "win arguments" either. I've said time and again through all my
debates with Paul that I have no interest in proving *him* wrong. My
only interest is in getting the science/facts right. I've also said
many times that I am not 100% certain of some of my claims, and am open
to being shown where I've been wrong. So please don't mis-characterize
me (underhandedly even) as some sort of argument troll. My statement
about wondering if you'd get further than I did with him, was not to
prove Paul wrong, but to establish what is technically correct in
regards to ergometer power and work. Paul has a big presence in the
online rowing community, and he's also a coach. As such it would be
nice if what he tells people isn't scientifically incorrect or misleading.
> for thought. I can see why it's hard to accept that ergs, the standard
> off-water training tool after all, could ignore such a large element of
> the rower's total work rate. I hope my analysis of the recovery may
> help to clear the air & add perspective to discussions of erg
> measurement accuracy.
>
> We might also take a squint at the consequences of work done on body
> accelerations on a fixed erg during the power stroke, & how this may
> skew the stroke force distribution that the machine will measure. It
> shouldn't be too hard to do. Any volunteers?
Not sure I follow you. Can you expound a bit?
Rekkers has several force curve plots on the rowperfect website that
compare fixed to floating rowperfect force profiles.
-KC
Carl Douglas
My question was rhetorical and the "we" was collective for all readers.
> Hopefully someone else's may be. What I'm questioning is that your
> analysis relies on a SR=40 to get your ~100W of unmeasured power. I was
> just pointing out that no one I know of ever ergs at a rate of 40spm, so
> to say that ">100W, typically, of the erger's average work rate goes
> unmeasured" is misleading. So, if you want to talk about 100 wasted
> watts, and stick to your analysis, then you should rephrase your
> statement that I quoted just there, especially the "typically" part.
> Your analysis seemed to have been prompted by Paul's claim that "it's
> nothing 'like 100 watts' that goes unaccounted for". If you're trying
> to defend your claim, which by your wording you certainly seemed to do,
> you fell a little short. But the analysis was still very informative.
Actually, I wasn't seeking to achieve 100W. Rough enough would've been
good enough. That popped up in my first calculation, with all those
assumptions that I listed, so I thought that's do for starters & we
could dissect it thereafter.
That's why I then added that further analysis on the influence of the
various chosen parameters. My first hit chose nice round numbers ;cos
it was all done by pencil & paper. Then I put it on a spreadsheet to
explore.
>
>>> 3.) I don't think you accounted for the work done by the bungee cord
>>> attached to the chain. I think a new erg has an average bungee
>>> tension on the order of 6lbf. Paul may remember the exact value(s).
>>> Anyway, the rower has to overcome that force on the drive, so in the
>>> end it may be safe to ignore on the recover, for it's not
>>> measured/included in the drive power calculations (on a C2) either.
>>
>> Correct. I ignored the cord tension.
>
> Why? It's easy enough to add in.
Too easy to bother? ;)
Not at all. We get further if we avoid winding each other up too much.
I'm not
> out to "win arguments" either. I've said time and again through all my
> debates with Paul that I have no interest in proving *him* wrong. My
> only interest is in getting the science/facts right. I've also said
> many times that I am not 100% certain of some of my claims, and am open
> to being shown where I've been wrong. So please don't mis-characterize
> me (underhandedly even) as some sort of argument troll.
I didn't. Now let's all be nice :)
My statement
> about wondering if you'd get further than I did with him, was not to
> prove Paul wrong, but to establish what is technically correct in
> regards to ergometer power and work. Paul has a big presence in the
> online rowing community, and he's also a coach. As such it would be
> nice if what he tells people isn't scientifically incorrect or misleading.
>
>> for thought. I can see why it's hard to accept that ergs, the
>> standard off-water training tool after all, could ignore such a large
>> element of the rower's total work rate. I hope my analysis of the
>> recovery may help to clear the air & add perspective to discussions of
>> erg measurement accuracy.
>>
>> We might also take a squint at the consequences of work done on body
>> accelerations on a fixed erg during the power stroke, & how this may
>> skew the stroke force distribution that the machine will measure. It
>> shouldn't be too hard to do. Any volunteers?
>
> Not sure I follow you. Can you expound a bit?
Perhaps, but not right now as I've work to do & a visitor trying to
navigate his way to us.
>
> Rekkers has several force curve plots on the rowperfect website that
> compare fixed to floating rowperfect force profiles.
>
true.
> -KC
paul_v...@hotmail.com
Well, the foot plate is at about a 45deg angle and without some sort
of support it's quite difficult to not push it away with just the
weight of the legs causing the feet to slide down. Would it be
acceptable to rig up a support plate that is parallel with the floor?
I wonder why you "suppose" I would not try this, I've probably tried
more things of interest on the Erg than you can imagine. Perhaps you
should put your brilliance out on a limb and make a guess as to what
rate would be possible under these circumstances. Show a little
confidence man! (I don't suppose you will. [See I can play that BS
game with you too.]) I've never said that the hamstrings don't fire
at all, surely they will, but they don't need to do very much, as the
recovery of the body has already gotten the momentum quite well
established as it tugged against the extended leg, which doesn't
stretch very much.
Carl's discussion makes it quite clear why my notion of training to a
fixed ratio (Fixed DPS) makes sense, as it translates directly into
training the recovery more appropriately for what will need to be
accomplished in a boat. But of course his numbers, as elegant as they
are, don't go anywhere near explaining why doing the same Pace/Rate
combination on Slides Vs On the grounded Erg is more difficult (on
slides). (As measured by cardiac output requirement.) Or
insignificantly different, if you prefer. I've gone back and forth
from day to day, or even within the same session, and the result was
always consistent with a moderate steady state pace.
Further more, if we do look at the guys who do R40 on the Erg (There
are a few from DEN), it's quite easy to see that they are LM and don't
move their COM anywhere near 0.6m. I'm still confused as to why Carl
see's "No counterpart in a boat" to the recovery on an Erg, there is a
direct counterpart, we have to drag the boat along and back into the
catch position after all.
- Paul Smith
Charles Carroll
Your write: "AFTER the seat racing is done, show EVERYONE in the group all
of the results, so the people who were cut can see that it was because they
weren't fast enough, and the people who made it, can believe that everyone
in the boat deserves to be there . . ."
As usual you get right to the heart of the problem - how to demonstrate with
mathematical certainty who deserves to be selected for a boat and who doesn't.
This is exactly what happened in the passage I quoted to Kieran from "The
Last Amateurs." Colin Scott by pulling better erg scores and winning his
seat races demonstrated that he had earned his seat in the provisional Blue
Boat. And his coach, Duncan Holland, gave it to him.
In making this selection Duncan Holland clearly was being fair. But was he
right?
The provisional Blue Boat's five returning crew didn't think so. They
disagreed with Duncan's selection. They wanted Dan O'Shaughnessy. It's not
that they didn't like Colin. Nor did they dispute Colin's numbers. But they
wanted Dan. What it came down to is something very nebulous. They simply
believed that they rowed better when Dan was in the boat.
According to Mark de Rond, "coaches may be able to get a good visual
impression of the boat but aren't necessarily a good judge of the 'feel' of
the boat." Also, Duncan Holland was dealing with an extraordinary crew -
'"two reigning World Champions, one former Olympic gold medalist and World
Champion, two world bronze medalists, and several others who had competed at
international levels."
So Duncan accedes to the wishes of his crew and Colin loses he seat to Dan.
Not only does it seem to me that Duncan's selection must have been very hard
on Colin, but it also points to something about selecting a crew. You can't
just select by the numbers. Mark de Rond points out that if it were that
easy, you could just get a computer to make the selection.
So what does it take to be a coach and make these selections?
This is something you must know from experience. From my perspective as an
outsider - and I freely concede that it is probably a very distorted
perspective - I would think that it must take an enormous amount of courage.
Cordially,
Charles
Dave Sill
>
> This is exactly what happened in the passage I quoted to Kieran from
> "The Last Amateurs." Colin Scott by pulling better erg scores and
> winning his seat races demonstrated that he had earned his seat in the
> provisional Blue Boat. And his coach, Duncan Holland, gave it to him.
>
> In making this selection Duncan Holland clearly was being fair. But was
> he right?
>
> The provisional Blue Boat's five returning crew didn't think so. They
> disagreed with Duncan's selection. They wanted Dan O'Shaughnessy. It's
> not that they didn't like Colin. Nor did they dispute Colin's numbers.
> But they wanted Dan. What it came down to is something very nebulous.
> They simply believed that they rowed better when Dan was in the boat.
They *believed* they rowed *better* with Dan? But seat racing showed
they were faster with Colin? And the coach went with Dan? And you think
that was a courageous decision? I'd say it takes more courage to go
against the will of the majority, but, backed by the facts, it'd be easy
to justify.
I just don't understand basing a line-up on a crew's subjective feeling.
Shouldn't speed be the primary criterion?
-Dave
KC
No, but it would be acceptable to rig up a wedge which attaches to the
foot plate to sufficiently increase the rake/slope of the foot so that
your foot doesn't slide off the top during the drive.
> I wonder why you "suppose" I would not try this, I've probably tried
> more things of interest on the Erg than you can imagine. Perhaps you
> should put your brilliance out on a limb and make a guess as to what
> rate would be possible under these circumstances. Show a little
> confidence man! (I don't suppose you will. [See I can play that BS
It's not BS. It was humility. I don't have time for it, so why should
I expect you to? If you do, and you're game, awesome! If not, I
understand. I thought you *might* be up for it, because I know that you
DO enjoy these kind of things (you've obviously made a career or
side-career out of it with PS-Sport) but didn't want to presume that you
would have the time.
This is not a test. I don't know how fast one would be able to erg with
such a setup. It's an honest question and I thought you of all RSR'ers
would be game and/or just as curious as I about the outcome.
> game with you too.]) I've never said that the hamstrings don't fire
> at all, surely they will, but they don't need to do very much, as the
I'm very glad that you now agree with the fact that the hamstrings are
required to move one from finish to catch during the recovery. You
didn't always agree with this fact. Here's a reminder of what was said
in the past:
> > Either way, all I'm telling you is
> > that you use your knee flexors more
> > than you think you do at high rates
> > on a static erg, and that this is
> > less so on a dynamic erg.
>
> It would have to be "more than I
> think I do", pretty much by definition.
> recovery of the body has already gotten the momentum quite well
> established as it tugged against the extended leg, which doesn't
> stretch very much.
>
> Carl's discussion makes it quite clear why my notion of training to a
> fixed ratio (Fixed DPS) makes sense, as it translates directly into
> training the recovery more appropriately for what will need to be
> accomplished in a boat. But of course his numbers, as elegant as they
> are, don't go anywhere near explaining why doing the same Pace/Rate
> combination on Slides Vs On the grounded Erg is more difficult (on
> slides). (As measured by cardiac output requirement.) Or
How are you measuring cardiac output? Hageman (spelling?) is the guy
you've quoted before on this, and his experiment did not, IIRC, try to
mimic the extra cooling one gets on a static erg that one does not get
on a floating/rolling erg. Decrease evaporative cooling at the skin is
going to cause increase HR, which has nothing to do with the work &
power requirements of the task of erging.
HR alone wouldn't tell you the whole story. Better to use VO2
consumption rates.
> insignificantly different, if you prefer. I've gone back and forth
> from day to day, or even within the same session, and the result was
> always consistent with a moderate steady state pace.
I've never disputed your anecdotal results, Paul, but that's all they
are: anecdotal. When I was training in 2006, I did several 5km tests on
c2c+slides at the boathouse and on my own c2c at home (no slides) and
consistently scored better on slides than on static erg. This is also
anecdotal, and proves nothing, except that you can't (shouldn't anyway)
take your own personal results as truth for all rowers.
-KC
Charles Carroll
Who would disagree that speed should be "the primary criterion" for choosing
a crew?
But what produces speed? Eight rowers with fast erg scores? Or eight rowers
who have won their seat races? Or eight rowers who row together as one?
I have a friend who has been trying to put together a double for years. He
told me that finally he thought he had found the ideal partner. Both of them
were excellent in a single. Both had very impressive erg scores. In their
age group on paper they were one of the fastest doubles in the States. But
on water was a different story. My friend said they weren't worth a damn on
water.
How does that happen?
Cordially,
Charles
KC
> Dave,
>
> Who would disagree that speed should be "the primary criterion" for
> choosing a crew?
>
> But what produces speed? Eight rowers with fast erg scores? Or eight
> rowers who have won their seat races? Or eight rowers who row together
> as one?
Yes, yes, and yes.
>
> I have a friend who has been trying to put together a double for years.
> He told me that finally he thought he had found the ideal partner. Both
> of them were excellent in a single. Both had very impressive erg scores.
> In their age group on paper they were one of the fastest doubles in the
> States. But on water was a different story. My friend said they weren't
> worth a damn on water.
>
> How does that happen?
Different styles, different timing, no swing/synchrony... any number of
things. The biggest mistake he made though is to think that he could
just put two great rowers in a double and expect it to move. A good
crew takes at LEAST a year to gel, and that's with good coaching 4-5x
per week, too.
-Kieran
> Cordially,
>
> Charles
Carl Douglas
Charles -
if you have rowed in a boat where, e.g., 1 guy bum-shoves & you don't,
especially if that crew was a 2x or 2-, then you'll absolutely
understand the vital importance of a good match between individual
dynamics in a crew.
In that situation, it is misery for both individuals as a large mass is
moving out of synch for each of them. At one part of the stroke the
boat feels unusually heavy while at another the stretcher goes away from
them. And that's with no other gross or subtle differences.
You can't row to your own best effect when the inputs of others generate
different & differently-sequenced impulses on the boat. And if the
physical proportions & muscle-group strengths of equally-sized,
equally-powerful rowers are different, that too can introduce a heap of
very tangible disruptive impulses.
For a crew to go its potential best, all those disparities would ideally
be absent. In reality we can only work towards good compromises &
accept the remaining rough edges. If crew members have to sacrifice too
much to reach the norm, or some fail to make the necessary adjustments
from time to time, then crew performance must also suffer - which may be
why the a crew can have great races & races where nothing feels right.
They do say that good crews are made only in heaven. At least it needs
crew members to be willing to feel the boat & then adapt intelligently
to what they feel. Many scullers have days when even getting
intelligent adaptation between their left & right hands is impossible :(
Mike Sullivan
"Carl Douglas" <ca...@carldouglas.co.uk> wrote in message
news:6mqvhsF...@mid.individual.net...
> Charles Carroll wrote:
>> Dave,
>>
>> Who would disagree that speed should be "the primary criterion" for
>> choosing a crew?
>>
>> But what produces speed? Eight rowers with fast erg scores? Or eight
>> rowers who have won their seat races? Or eight rowers who row together as
>> one?
>>
>> I have a friend who has been trying to put together a double for years.
>> He told me that finally he thought he had found the ideal partner. Both
>> of them were excellent in a single. Both had very impressive erg scores.
>> In their age group on paper they were one of the fastest doubles in the
>> States. But on water was a different story. My friend said they weren't
>> worth a damn on water.
>>
>> How does that happen?
>>
>> Cordially,
>>
>> Charles
>
> Charles -
>
> if you have rowed in a boat where, e.g., 1 guy bum-shoves & you don't,
> especially if that crew was a 2x or 2-, then you'll absolutely understand
> the vital importance of a good match between individual dynamics in a
> crew.
In a double the problem is difficult, because even in the absence of the
above problem where bodies are moving at obviously differing speeds and the
boat feels out of sync, you can have a double where both scullers are fast
single scullers, the boat feels like it's going well but is getting beat by
"lesser"
scullers - note the quote.
As to seat racing, I wrote a long story years ago I think about a
nat'l camp seat race period where A beat B beat C beat A consistently
It's hilarious unless you told the athletes that you'd be using seat
racing for boat selection.
I always told my athletes that seat racing was 'sort of objective'.
Rob Collings
> In a double the problem is difficult, because even in the absence of the
> above problem where bodies are moving at obviously differing speeds and the
> boat feels out of sync, you can have a double where both scullers are fast
> single scullers, the boat feels like it's going well but is getting beat by
> "lesser" scullers - note the quote.
Lesser single scullers but a superior crew combination? I've been
there before. Or with 3 scullers who are all similar speeds in the 1x,
but only have one combination that makes a quick 2x.
> As to seat racing, I wrote a long story years ago I think about a
> nat'l camp seat race period where A beat B beat C beat A consistently
Any chance of someone digging out a link to it?
> It's hilarious unless you told the athletes that you'd be using seat
> racing for boat selection.
It's just another imperfect tool to add to the box. The problem is
(and we've been here before) that as coaches we want to be able to
take all available information and use our judgement. But as athletes,
many of us like to see it in black and white why we aren't in the
boat. The first approach isn't often very transparent, but the latter
simplifies things too far.
Rob.
Dave Sill
>
> Who would disagree that speed should be "the primary criterion" for
> choosing a crew?
>
> But what produces speed? Eight rowers with fast erg scores? Or eight
> rowers who have won their seat races? Or eight rowers who row together
> as one?
I'd argue that eight good and well-matched rowers who train hard under a
good coach are pretty likely to be fast. What I question is the wisdom
of letting seven of the rowers override the coaches pick of the eighth.
They might "feel" that they row "better" with their pick, but that
doesn't mean they'll be faster. They may initially feel more comfortable
with their pick, but maybe they just need to spend time rowing with the
coach's pick and under the coach's supervision in order to become
comfortable with his pick. A competent coach will realize pretty quickly
if someone's not compatible with the rest of the crew.
-Dave
Charles Carroll
I am surprised that no one has addressed Mark de Rond's statement that
"coaches may be able to get a good visual impression of the boat but aren't
necessarily a good judge of the 'feel' of the boat."
It seems to me that this statement does not come whole cloth from Mark de
Rond. It is Mark's summary of the returning crew's thinking. It seems to me
that the crew really believed that they had a 'feel' for the boat that
eluded the coaches.
If I am right, then doesn't this introduce a question of what this 'feel' is
and just how much important should a coach give it?
Is it anything you can measure? And if it isn't, then doesn't mean that it
has to be "subjective?"
I remember a few months ago when I was discussing my new Croker sculls. I
said something like these sculls felt good to me in a way that other sculls
don't.
Immediately some of the wise heads on rsr cautioned me not to place too much
importance on 'feeling.' They said that a boat can feel really good and be
slow, and that it can also not feel good and be fast.
Yet Duncan Holland seemed to place a lot of importance on how the boat felt
to the crew. Or maybe he felt he didn't have a choice.
In any event I am reminded what David Halberstam wrote about Harvard's
Varsity Men's 8+ in 1974 and 1974, the "Rude and Smooth" crew. While there
is no doubt that there were extraordinary rowers in the boat, didn't this
crew also have an extraordinary 'feel' for itself as a crew? Didn't they
routinely beat crews that on paper should have hammered the daylights out of
them? I am thinking of when they raced the Huskies.
I just am curious what people who have had a seat in a boat and raced
seriously think about "the 'feel' of the boat."
Cordially,
Charles
Mike Sullivan
"Rob Collings" <robin.c...@gmail.com> wrote in message
news:60c8b170-23f5-4256...@y29g2000hsf.googlegroups.com...
On 29 Oct, 17:04, "Mike Sullivan" <s...@slacSNIP.stanford.edu> wrote:
snip
> It's just another imperfect tool to add to the box. The problem is
> (and we've been here before) that as coaches we want to be able to
> take all available information and use our judgement. But as athletes,
> many of us like to see it in black and white why we aren't in the
> boat. The first approach isn't often very transparent, but the latter
> simplifies things too far.
This part of coaching was what made my skin break out in itchy rashes
from january to june.
Mike Sullivan
"Charles Carroll" <charles...@comcast.net> wrote in message
news:6mrstpF...@mid.individual.net...
> Carl,
snip
> In any event I am reminded what David Halberstam wrote about Harvard's
> Varsity Men's 8+ in 1974 and 1974, the "Rude and Smooth" crew. While there
> is no doubt that there were extraordinary rowers in the boat, didn't this
> crew also have an extraordinary 'feel' for itself as a crew? Didn't they
> routinely beat crews that on paper should have hammered the daylights out
> of them? I am thinking of when they raced the Huskies.
the 74-75 crew had Shealy,Cashin, Fellows, Stone, Wood, Kemp(75)
Weinberg(cox) all were
nat'l teamers. UW won the IRA with Norelius, Brinsfield, and Alsopp, also
Natl
teamers. Noro, Shealy, and Cashin all won WC the summer of '74 in the
eight.
nobody beat that vard crew on paper or in any other way, one of the best
college crews ever.
Mike Sullivan
"Mike Sullivan" <s...@slacSNIP.stanford.edu> wrote in message
news:geafof$35k$2...@news.stanford.edu...
I should add, as a point of interest that Fellows/Brinsfield rowed in nat'l
4+
together, and Stone, Wood, and Alsopp at one time or another was the Nat'l
sculler.
Charles Carroll
Mike,
I stand corrected.
What led me to this erroneous impression was the following passage from “The
Amateurs.”
“Other crews hated Shealy and the Harvards; it was bad enough to row against
them and be beaten every time, but his cockiness made it all the worse.
“A race with the University of Washington had highlighted the Harvard crew’s
elitism. Since most of Harvard’s victories were against eastern crews, the
Washington oarsmen regarded the race as one for the national championship.
In the eyes of the Harvard oarsmen, a race on that same trip against
Wisconsin, a race they had barely won, had already given them the national
title. Before the race, to be held in Seattle, Shealy had played his usual
gamesmanship by announcing plans for a naked heliborne raid on the Seattle
Space Needle. The Washington oarsmen were duly offended by the Shealyisms
(‘I think that they probably saw us as a bunch of extremely arrogant
upper-class prep-school-Harvard kids, and I think they were probably right,’
Shealy said years later.) The Washington oarsmen had their own means of
retaliation. Timing was critical. At the exact moment that the Harvard crew
arrived at the boathouse, the Washington oarsmen were getting ready to row.
They were immense, obviously the biggest crew in the country. They all wore
dark glasses, they had all shaved their heads, and they were stripped to the
waist and oiling their bodies. They were at least fifteen pounds a man
heavier. But it was more than that, Shealy thought, they were ominous, so
big and muscular, ‘like genetic defects, with these huge, bulbous muscles.
Like primitive man. We were these skinny, snotty, little eastern kids.’
Harvard won two lengths. With a third of the race left and Harvard pulling
ahead, Shealy had yelled, ‘Farewell, Huskies!’”
I believe that I got my mistaken impression from Halberstam’s assertion the
Washington crew was “at least fifteen pounds a man heavier.” I just assumed
that on paper they looked like the stronger crew.
Isn’t it amazing that Tiff Wood his freshman year at Harvard weighed about
165 pounds and tried for the lightweight crew?
The son of a friend is currently in his freshman year at Cal on a rowing
scholarship. He prepared at St. Ignatius, was in the Varsity boat there, but
thinks he is too small for anyone to take a serious interest in him. He grew
a bit this summer, so I believe that now he is almost 6 feet 5 inches tall
and weighs about 185 pounds.
Cordially,
Charles
Mike Sullivan
>> nobody beat that vard crew on paper
>
> Mike,
>
snip
> I believe that I got my mistaken impression from Halberstam’s assertion
> the Washington crew was “at least fifteen pounds a man heavier.” I just
> assumed that on paper they looked like the stronger crew.
Halberstam (RIP) was guilty of much hyperbole. UW guys were big
but not any bigger than the Vards. The guy that was scary looking was
Brinsfield their stroke. He looked a bit like 'roided out Brian Bosworth
and when your eye draws to him it can create an impression.
Also in that UW crew was Alsopp who was lanky and lean soph, and
George Naden who was not a big guy at all, eventually made a
US light team, but he really shouldn't have done that - he looked
awful, I hope he didn't damage his liver those couple years. I could
be mistaken, George might have been '75 not '74.
UW's biggest and best was Noro who was a body match for Cashin.
They are rowing in this video here:
http://video.google.com/videosearch?q=1974+burnaby+sprints+rowing&emb=0&aq=f#
they are winning their heat at 9:40 in the vid and there's a brief shot
of them at 13:23 holdiing off Irvine's sprint and hammering Cal.
>
> Isn’t it amazing that Tiff Wood his freshman year at Harvard weighed about
> 165 pounds and tried for the lightweight crew?
Ibbetson weighed 155 his frosh year and about same height as Wood.
Both he and Tiff were in the 1980 US crew that set a flat water record
at Lucerne that stood for 20 years, 5:30.
It was seeing lot of guys succeed like this in the 70s and 80s that
led me to oppose lightweight rowing (as well as seeing what George
and some others did to themselves).
>
> The son of a friend is currently in his freshman year at Cal on a rowing
> scholarship. He prepared at St. Ignatius, was in the Varsity boat there,
> but thinks he is too small for anyone to take a serious interest in him.
> He grew a bit this summer, so I believe that now he is almost 6 feet 5
> inches tall and weighs about 185 pounds.
He's got a lot of room to build strength. Sky's the limit.
Charles Carroll
>
> They are rowing in this video here:
>
> http://video.google.com/videosearch?q=1974+burnaby+sprints+rowing&emb=0&aq=f#
Mike,
I finish work, go upstairs and think I have twenty minutes or so, so I'll go
down to the basement and play on the erg for bit.
But before I do, I look to see if there are any new posts on rsr.
Next thing I know I'm late for dinner.
Was 1974 your senior year at UCI? You wouldn't by any chance be in this
video, would you?
Cordially,
Charles
KC
Charles,
Mike was 5 seat in the '74 UCI varsity 8+. There are several shots of
him from a distance, but at about 11:30 in that video, after the heat,
when the crew is carrying the boat, you get a good view of Sul face-on.
(If that's what you're really looking for...) ;-)
BTW, there are two versions of that video, a 15min one and a 22min one.
The 22min one was digitized in widescreen format and thus is all
distorted. Watch the 15min one... same stuff, proper shape.
UCI's performance at the '74 Western Sprints was a big part in Bob Ernst
(Mike's coach at UCI) landing his job at UW (where he still coaches).
I think the 74 varsity's 2nd place at Western Sprints was the highest
Irvine ever placed. I don't think we've done that well since. We were
5th in 1992, and haven't done that well since '92 either. Although the
Western Sprints no longer exists in the form it was then. Pac10 now has
it's own championship so a victory at Sprints or whatever it's called
now, is not a true west coast championship, since Cal, UW, Stanford, and
OSU all race at the Pac10s and (generally) not at the "other regatta"
(don't know what they call it now, it's been called Western Sprints,
PCRC's, WIRA champs, and probably several other things.)
Mike and I disagree on this I think, but until someone endows a huge
scholarship fund for rowing at UCI, it will never have the success it
did in the 70's, 80's and early 90's. UC Irvine just does not attract
the kind of athletes that make good rowers.
Speaking of which, your friend's son at Cal is most likely plenty big
enough to be successful there. 6'5" is a great height for a rower at
that level, and he has lots of room to add muscle. That said, he may
have a build like my friend Colin, who is 6'5.5", and could not for the
life of him get heavier than 182 or so. He's a natural lightweight
who's just a few inches too tall to be light enough for lightweight
rowing. He got himself down to LWT range once, and vowed never to do it
again - he was miserable and unhealthy. But he's just one of those
"thin as a rail" high metabolism, lean muscle types. He lifted weights
like a madman for years, and never got up to 185. It's too bad, too,
because he's got a huge VO2max, so can last forever, but just doesn't
have the sheer strength to pull a really fast 2k erg. I can beat him on
the erg and in a boat, but put us on bicycles where weight matters, and
he kills me. Great triathlete though. But anyway, even if the boy is
doomed to peak his weight at 185 or so, he's probably still capable of
rowing successfully at Cal, maybe just not at the Olympics.
-KC
sully
> Charles Carroll wrote:
> >> UW's biggest and best was Noro who was a body match for Cashin.
snip
>
> Mike was 5 seat in the '74 UCI varsity 8+. There are several shots of
> him from a distance, but at about 11:30 in that video, after the heat,
> when the crew is carrying the boat, you get a good view of Sul face-on.
> (If that's what you're really looking for...) ;-)
Well, this was why I was able to speak so authoritatively. I gave
Noro
my shirt. That summer he was named 'best oarsman in the world' by
some nebulous phantom declaration. In the next couple few years I
rowed against and with all those guys in trials and camps.
I had never seen this film until my friend Bill got it digitized.
When I
coached I had it but couldn't bear to watch it, it was that painful.
The funny thing about it now is that for years I had been telling
myself
we closed on UW and lost by .7 seconds. It was actually more like
1.7 which was a solid 1/2 length.
Don't leave JD out, KC, he was at 7.
>
> BTW, there are two versions of that video, a 15min one and a 22min one.
> The 22min one was digitized in widescreen format and thus is all
> distorted. Watch the 15min one... same stuff, proper shape.
>
> UCI's performance at the '74 Western Sprints was a big part in Bob Ernst
> (Mike's coach at UCI) landing his job at UW (where he still coaches).
We never had a good performance that year. I think we had faster
boat
speed than both Cal and UW. We'd all raced small boats over two
summers
at US nat'ls and Canadian Henley, and won top 3 in every event pretty
much.
We had 3 pairs in the senior finals at the '73 Canadian Henley,
finishing 2,3,5.
I think we probably had the fastest boat speed and best rowing in the
US, but I don't think we were good racers other than our stroke man.
I don't fault
our dedication to work, the outstanding discipline of our coach, or
our faith in each other for one instant, though.
I understand the phenomenon really well, though, how you can be very
fast and not win. no inclination for it tonight.
It hurts!
Mike
KC
> On Oct 29, 9:03 pm, KC <kc_n...@sonic.net> wrote:
>> Charles Carroll wrote:
>>>> UW's biggest and best was Noro who was a body match for Cashin.
>
> snip
>> Mike was 5 seat in the '74 UCI varsity 8+. There are several shots of
>> him from a distance, but at about 11:30 in that video, after the heat,
>> when the crew is carrying the boat, you get a good view of Sul face-on.
>> (If that's what you're really looking for...) ;-)
>
> Well, this was why I was able to speak so authoritatively. I gave
> Noro
> my shirt. That summer he was named 'best oarsman in the world' by
> some nebulous phantom declaration. In the next couple few years I
> rowed against and with all those guys in trials and camps.
>
> I had never seen this film until my friend Bill got it digitized.
> When I
> coached I had it but couldn't bear to watch it, it was that painful.
>
> The funny thing about it now is that for years I had been telling
> myself
> we closed on UW and lost by .7 seconds. It was actually more like
> 1.7 which was a solid 1/2 length.
Yes, when you first told me about that race, I recall you using a
somewhat vulgar description of a very small distance, to describe by how
much you lost to UW. When I watched the video I was kinda scratching my
head, thinking ... "We're all victims of the older we get the faster we
were..." LOL.
I have a friend who swears we went sub 5:50 on flat water, no wind at
Occoquan in '94. It was 5:52, several of us confirm the same number.
But he swears it was sub 5:50.
>
> Don't leave JD out, KC, he was at 7.
>
Charles was only asking about you. Sorry JD!
>
>> BTW, there are two versions of that video, a 15min one and a 22min one.
>> The 22min one was digitized in widescreen format and thus is all
>> distorted. Watch the 15min one... same stuff, proper shape.
>>
>> UCI's performance at the '74 Western Sprints was a big part in Bob Ernst
>> (Mike's coach at UCI) landing his job at UW (where he still coaches).
>
> We never had a good performance that year. I think we had faster
> boat
> speed than both Cal and UW. We'd all raced small boats over two
> summers
> at US nat'ls and Canadian Henley, and won top 3 in every event pretty
> much.
>
> We had 3 pairs in the senior finals at the '73 Canadian Henley,
> finishing 2,3,5.
>
> I think we probably had the fastest boat speed and best rowing in the
> US, but I don't think we were good racers other than our stroke man.
> I don't fault
> our dedication to work, the outstanding discipline of our coach, or
> our faith in each other for one instant, though.
>
> I understand the phenomenon really well, though, how you can be very
> fast and not win. no inclination for it tonight.
Went mountain biking with Jed and Aaron today. Aaron and I were talking
about the idea of breaking an 8+ into pairs for training. I'm not
convinced that pairs training really translates well back to boat speed
in an 8. Too many skills must be learned to make a pair go well that
have no place in an 8. Don't get me wrong, I love the pair - probably
my favorite boat to row. And few workouts are as competetive and
intense as when you have 2, 3, or more pairs that are closely matched,
duking it out for 5 x finish line to turning basin pieces. But I still
think that a lot of the learning that goes on is wasted if your goal is
to make the 8 fast.
-KC
Charles Carroll
Ok at 11:30 or thereabouts I see three guys carrying an 8+. The first has a
sweatshirt or sweater with horizontal stripes around his neck. The second
has a plain sweatshirt, also around his neck. The third has a T-shirt with
USA across the front. My guess would be the third is Mike.
On second thought I have looked at the video for about the tenth time. I don't
think the guy with the USA T-shirt is Mike. His face is too full. I would
say either it is the first guy or the second guy. Probably the second guy,
that is the middle guy, because he looks very sober and a little pissed off.
The first guy with the horizontal stripes looks a little too toothy and
happy to be Mike. But the second guy has this sort of Bobby Zimmerman
hairdo. He looks earnest and very determined.
But the truth is it could be any one of them. I just can't tell. I am just
no damn good at these things. It is too long ago and the video is too
blurry.
I think I owe you and Mike and JD an apology. My young friend who is
starting at UC - I have thought about telling you about him for a couple of
months now. The first school that accepted him was UCI. Apparently it really
wanted him. But he was looking at Georgetown and Princeton and Cal, and had
a hard time making up his mind.
I have known this kid since he was fourteen. He is one of the nicest young
men you will ever meet. He's polite, he's friendly, he's outgoing, there is
absolutely nothing about him in any way that is self-aggrandizing or
self-important, and probably he's a very good rower. And on top of all this
he has a 3.8 GPA from St. Ignatius. So it is a GPA without grade inflation.
When his mother told me that UCI was the first school to accept him, my
first thought was that it might be ideal. And I don't mean just because you
and Mike and JD went there. We have a member of our family, Sandy's family
really, who has just gotten her PhD from UCI. She doesn't know a thing about
crew, but she loved the school.
I thought maybe I should give Mike a chance to go rowing with him and talk
about UCI. But he's not my son, and it really isn't any of my business.
Oh well, his mother says that he is doing OK at Berkeley and really is
enjoying crew, so I guess that means something.
The only thing that bothers me is that before he left he told me that he
thought that he only had a year left of rowing. I thought that was a
ridiculous thing for a seventeen year old to say. But he assured me it wasn't.
He said that his back and knees were going, and that he would be happy to
get through a year without injury. All I could say was that I believed he
would find some really good coaches at UC, and that they would teach him
techniques that would significantly reduce the risk of injury.
It drives me crazy to think that someone could be just seventeen years old
and believe his rowing career was nearing its end. It is way too young. At
seventeen he should be at the start of his career, not the end. I don't know
why we're not doing more to teach people to row correctly. Back injury and
rowing don't have to be synonymous.
Cordially,
Charles
sully
> sully wrote:
> > On Oct 29, 9:03 pm, KC <kc_n...@sonic.net> wrote:
> >> Charles Carroll wrote:
> >>>> UW's biggest and best was Noro who was a body match for Cashin.
snip
> > I understand the phenomenon really well, though, how you can be very
> > fast and not win. no inclination for it tonight.
>
> Went mountain biking with Jed and Aaron today. Aaron and I were talking
> about the idea of breaking an 8+ into pairs for training. I'm not
> convinced that pairs training really translates well back to boat speed
> in an 8. Too many skills must be learned to make a pair go well that
> have no place in an 8. Don't get me wrong, I love the pair - probably
> my favorite boat to row. And few workouts are as competetive and
> intense as when you have 2, 3, or more pairs that are closely matched,
> duking it out for 5 x finish line to turning basin pieces. But I still
> think that a lot of the learning that goes on is wasted if your goal is
> to make the 8 fast.
The pair is a tool. It is a difficult one to employ properly, and a
coach who can do that can probably coach eights without using pairs.
At UCI, there was a history before me of beating Cal and UCLA, both
of which had had impressive programs. The crews that won were really
good.
The Cal crews were the worst in their history, though. Our varsity
beat Cal in 1972 when we finished 2nd in the petites at sprints.
In my years, small boats were employed minimally during the year, but
far more than other programs were doing., The key was that Ernst ran
a summer program in small boats from the end of Sprints to a
championship regatta in late July or early August. In this program,
we trained exclusively in small boats and actually trained harder and
more intensely than in the college season.
I did the same thing when I coached, though I wasn't as successful as
Ernst.
Other coaches would warn me about burning out athletes, but the
change of pace, the complete emphasis on small boats added a dimension
of experience to the sport of rowing that was enhancing, not tiring.
We raced in Philly, in St Kitts, in Camden, against the best in the
country.
We trained 2-3 times a day that seemed like a vacation rather than a
strain based upon the bonds we forged.
My frosh year we lost to every single crew we raced against.
My senior year we competed well against the very best college
crews in the country.
bittersweet. we're a well-deserved footnote. Winning makes history.
sully
wrote:
> Kieran,
>
snip;
> But the truth is it could be any one of them. I just can't tell. I am just
> no damn good at these things. It is too long ago and the video is too
> blurry.
I hate to watch that vid so I can't help you, Charles. The day
before
in the heat we got open water on Cal in 400 meters and rowed at 38
into a screaming headwind until we hit the wall. The heat was in the
vid, btw.
We were a pathetic finishing crew. The next day when I gave my shirt
to Noro he thanked me for taking the edge off Cal for him.
I don't have a ready answer for your friend's kid. Cal's program is
top in the nation so there is the temptation to believe that there's
some weird pathology occurring. But in very bad programs there are
kids who find they can't do it.
I've had outstanding athletes that found reasons not to row where they
would be wildly successful in the program physically.
If you think this is a problem I would be happy to talk to the kid, or
to the kids parents. The kid is my kids' age, and I'll guarantee you
that he doesn't work as hard as my daughter does in sport, yet my son
is not at all interested in competing in sport, he's an engineering
student with a girlfriend
from hell.
\
I"m serious, hook us up!
Carl Douglas
While I might not use those terms, Paul, you're dead right in saying
that we have to drag the boat along (with our feet) to reach the catch
position.
What generate these sometimes large differences in recovery energy
required for fixed erg vs boat or sliding erg is that kinetic energy is
an M.V^2 term. As my examples show, at lower rates the recovery energy
element is not that high, but rises steeply & non-linearly with rating &
with stroke length. With a boat, the rather low boat mass is given
similar but lesser accelerations, so the energy terms are much smaller.
Sure, continuous work is done during recovery to overcome the
(non-linear with velocity) fluid drag forces, but there is no
counterpart in boat or well-designed sliding erg to the work done only
on the fixed erg to decelerate the body mass just before the catch.
Perhaps I might digress on that last point, since it may have some
bearing on that part of the parallel discussion on this thread between
Sully & Charles concerning the premature termination of a 17-yr old's
rowing career? Too often, fixed erg rowers cheat at the catch (not
consciously!) by failing to actively decelerate as they approach
frontstops. Instead, they allow the over-extension & recoil of their
knee joints to store & partially return the kinetic energy that they had
invested in generating their stretcher-wards motion necessary to make
the recovery. This is something I've seen far too often to find funny.
And I'm advised by folk more knowledgeable on the function of the knee
joint that, for some of us, this can generate a heap of permanent damage
there. Similarly, the corresponding jarring to the unprepared lower
back region of this "ballistic" checking, which only a fixed erg allows
the over-keen rower to generate, would seem a not unlikely cause of
lower back problems.
Finally, I think my 0.6m movement of the CG is a very reasonable
assumption for an 85kg rower. If of a normal 6-footer build his seat
will move 65cm or more. His upper body, head & arms clearly move more
than that. The top of his thighs also moves the same 65cm & I agree
that the amount of movement then reduces progressively to zero by the
time you reach the toes but the cross-section & local mass of the legs
also tapers off rapidly. As for the male lightweights, a large number
of them are also 6-footers & lanky, but I've always argued that
lightweights try harder.
I'll rest my case on that for now, but I did provide data for other
scenarios deliberately to encourage this kind of examination.
KC
> On Oct 29, 11:59 pm, "Charles Carroll" <charles_carr...@comcast.net>
> wrote:
>> Kieran,
>>
> snip;
>
>> But the truth is it could be any one of them. I just can't tell. I am just
>> no damn good at these things. It is too long ago and the video is too
>> blurry.
>
> I hate to watch that vid so I can't help you, Charles. The day
Sully is the second of the three you describe, and, if I'm counting
seats right, the first should have been JD... but I'm not sure. I don't
know who the USA sweatshirt guy is.
> before
> in the heat we got open water on Cal in 400 meters and rowed at 38
> into a screaming headwind until we hit the wall. The heat was in the
> vid, btw.
> We were a pathetic finishing crew. The next day when I gave my shirt
> to Noro he thanked me for taking the edge off Cal for him.
>
>> I think I owe you and Mike and JD an apology. My young friend who is
>> starting at UC - I have thought about telling you about him for a couple of
>> months now. The first school that accepted him was UCI. Apparently it really
>> wanted him. But he was looking at Georgetown and Princeton and Cal, and had
>> a hard time making up his mind.
No apologies necessary. This is my point about Irvine rowing. No good
rowing recruit in his right mind would want to go there if he could get
in to Cal or Princeton. The University is excellent, but who would want
to row for a podunk program when you could row for one of the best in
the country? It's a very hard sell, and it's an impossible sell when
you consider that Cal is offering the lad a scholarship to boot. All
Irvine can do his offer a tiny bit of help on admissions (at least we
used to offer that, not sure any more).
Charles, here's where I agree with Sully's take on Jr's rowing (i.e.
high school) in many cases it can lead to physical problems and
injuries, because the bodies are still growing and developing so much
then. Better to do a little bit of lots of sports, than to focus
exclusively on crew in highschool. If he really loves rowing, and wants
to continue it for a long time, he might be advised to red-shirt a year
at Cal, and spend that year in the training room instead of the
boathouse, and not ever come even close to an erg or a boat. If he were
to work as hard on physical therapy for his back as he might otherwise
work toward making a frosh boat, then he might have a chance at
completely fixing the problem and being good to go for 4 years in the
varsity/jr.varsity squad. Of course I have no idea what his problem is,
but I do know a thing or two about back problems and rowing (living with
a herniated L5/S1 disc and concomitant chronic sciatica myself).
>
> I don't have a ready answer for your friend's kid. Cal's program is
> top in the nation so there is the temptation to believe that there's
> some weird pathology occurring. But in very bad programs there are
> kids who find they can't do it.
>
> I've had outstanding athletes that found reasons not to row where they
> would be wildly successful in the program physically.
>
> If you think this is a problem I would be happy to talk to the kid, or
> to the kids parents. The kid is my kids' age, and I'll guarantee you
> that he doesn't work as hard as my daughter does in sport, yet my son
> is not at all interested in competing in sport, he's an engineering
> student with a girlfriend
> from hell.
ROTFLMAO!
-KC
Mike Sullivan
"KC" <kc_...@sonic.net> wrote in message
news:4909ca04$0$33568$742e...@news.sonic.net...
> sully wrote:
>> On Oct 29, 11:59 pm, "Charles Carroll" <charles_carr...@comcast.net>
>> wrote:
>>> Kieran,
snip
>>> It drives me crazy to think that someone could be just seventeen years
>>> old
>>> and believe his rowing career was nearing its end. It is way too young.
>>> At
>>> seventeen he should be at the start of his career, not the end. I don't
>>> know
>>> why we're not doing more to teach people to row correctly. Back injury
>>> and
>>> rowing don't have to be synonymous.
>
> Charles, here's where I agree with Sully's take on Jr's rowing (i.e. high
> school) in many cases it can lead to physical problems and injuries,
> because the bodies are still growing and developing so much then. Better
> to do a little bit of lots of sports, than to focus exclusively on crew in
> highschool. If he really loves rowing, and wants to continue it for a
> long time, he might be advised to red-shirt a year at Cal, and spend that
> year in the training room instead of the boathouse, and not ever come even
> close to an erg or a boat. If he were to work as hard on physical therapy
> for his back as he might otherwise work toward making a frosh boat, then
> he might have a chance at completely fixing the problem and being good to
> go for 4 years in the varsity/jr.varsity squad. Of course I have no idea
> what his problem is, but I do know a thing or two about back problems and
> rowing (living with a herniated L5/S1 disc and concomitant chronic
> sciatica myself).
I know nothing of the kid, but SI's program is very reasonable, they
row during a "season" and not all year, the kids play other sports as well.
I had back problems all thru HS, it damaged my progress in track my
senior year. I stretched and did all the things you were supposed to
in the 60s, but it wasn't until I started strength building and tons of ab
work for rowing that the back pain disappeared completely and didn't
come back until I became a lazy old man.
Mike Sullivan
> Kieran,
>
> Ok at 11:30 or thereabouts I see three guys carrying an 8+. The first has
> a sweatshirt or sweater with horizontal stripes around his neck. The
> second has a plain sweatshirt, also around his neck. The third has a
> T-shirt with USA across the front. My guess would be the third is Mike.
>
> On second thought I have looked at the video for about the tenth time. I
> don't think the guy with the USA T-shirt is Mike. His face is too full. I
> would
"USA" is JD, I'm the guy with the really bad moustache and the 'fro looking
right at camera right before JD. Yes, that is a moustache, it's not snot
running
out of my nose.
I think I looked like Napoleon Dynamite.
The only thing goofier than my facial hair is when I shaved my head in the
summers
of '73 and '74. I was the only non-military guy in the USA with a shaved
head.
My head is pointy and my nose is big so I looked like one of the "goonies"
in
the old Popeye cartoons.
http://www.archive.org/details/PopeyeInGoonlandoctober14th.1938
There is film and photo evidence
of that look out there somewhere. (shudder).
wmar...@gmail.com
wrote:
Having just recently hosted the coach of the 2008 Olympic gold medal
M8+ and having had many conversations....
Coaches can't "feel" what the athletes feel - we have to use things
like stopwatches - and "feel" doesn't win races, speed does. Mike
reports regularly asking athletes how a row felt, and seems to report
frequently that when the boat felt like "shzt" on the end of a stick,
it was going faster than before, and when it felt "right" it wasn't
necessarily going as fast as when if felt "like crap".
Right up to their departure for World and Olympic competition (i.e.,
about 2 weeks before departure) he reports training approximately 50%
in small boats, (1x, 2-, and 4-) and about 50% in the 8+.
I believe that if you can't move a pair, why would I want you in an
8+?
It should be also noted that these are my opinions, backed by my
experience at club and, provincial level in Canada and New Zealand,
and observation of various international crews, but they are not
necessarily the opinion of my employer.
I can't really comment on how 'selections' go at the two poncy pom
university programmes - seems each year there's some kind of
controversy...
Interesting video of Western Sprints at Burnaby - it's where I used to
train, but since then the lake has silted in for much of the last 500
m, and the boat-in area that was in use during the Sprints (and the
1973 Canada Games for which the lake was dredged and buoyed
originally) is no longer useable...
W