Weighting a challenge

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webberg
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Weighting a challenge

Post by webberg »

I'm trying to put together an algorithm so that we can all do a certain distance and calculate a coefficient that should put us pretty close together. This will be weighted for the following factors;

Sex (answer is not "yes please")
weight
age
height

The weight and age markers I intend to steal from the C2 website although these are for 2k and therefore I will adjust them for a 5k piece.

The male/female adjustment I will calculate from the C2 ranking tables. My initial data suggests that men are about 20% quicker over any distance (and true of more disciplines than rowing) and this is where I will start.

Height is a problem as data is scarce. The physics or rowing means that tall people will always be quicker because they c an apply more power over a longer distance. (Thomas is this correct?)

My base line therefore is a 6 ft tall rower. For every inch over that height I will add a handicap to the recorded time. For every inch lower a reduction. As an absolute guess on a 5k piece (10 x 500) I think that every inch will be worth 1 sec per 500. Therefore a 6 ft vs a 6'6" will have an advantage of 6 secs per 500 or 1 minute over the piece.

I would appreciate comments.

The idea is to incentivise good times so that an outstanding short person can compete with a tall person.

For example, I am 5'8" and 84kgs. My 5k PB is 21:13. I am 49 years old (damn it). The weight adjustment per C2 is 1.022 over 2k. This gives a time of 21:41.

The age adjuster says to deduct 21.4 secs per 2k. Over 5k this is 52.5 secs. Sub total 20.48.5.

For a woman this would the be further reduced by a factor I have yet to calculate.

The height adjuster would be 4 secs per 500 (i.e, 6 ft less 5'8" x 10) or 40 secs. Net time is 20:08.5. RESULT!! :lol:

A 6'4", 100kg, guy doing 18:50 aged 35 comes out at 22:58.5.

Probably therefore needs some work.

I would appreciate comments from the mathos out there.

Please be gentle. I'm a corporate financier not a numbers monkey.
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Thomas W-P
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Re: Weighting a challenge

Post by Thomas W-P »

webberg wrote:Height is a problem as data is scarce. The physics or rowing means that tall people will always be quicker because they c an apply more power over a longer distance. (Thomas is this correct?)
Work done (energy) = force x distance

So assuming that a tall person can apply a constant force for a longer distance they will be able to give more energy to the flywheel each stroke.

The speed of the wheel is proporional to the square root of the energy applied per second (or power), so the benefit is pretty small but measurable. (I think- I am a fake physics teacher - my degree was production engineering!)

Anyway, they still need to get the energy from somewhere, but it stands to reason that a taller person has more mass and therefore a greater ability to store energy.

Probably all codswallop but it sounds impressive.
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Re: Weighting a challenge

Post by ReducingFB »

webberg wrote: Please be gentle. I'm a corporate financier not a numbers monkey.
Well! If you're no good with numbers, I'm not coming to you for financial advice !! :twisted:

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Post by Stan »

Just found this link while browsing the c2 forum. Some interesting stuff on the science of rowing. You may find some relevant stuff Graham.
http://daily-erg-workout.blogspot.com
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Re: Weighting a challenge

Post by JanetS »

Very interesting link Stan - some good stuff on setting training intensities.
Thomas W-P wrote: Anyway, they still need to get the energy from somewhere, but it stands to reason that a taller person has more mass and therefore a greater ability to store energy.

Probably all codswallop but it sounds impressive.
Ah - but you've already allowed for mass once so by adding height are you essentiallly adjusting for mass twice?
Another way of looking at it could be to say that for two rowers of the same mass the taller one is more likely to have a greater proportion of that mass contained in muscle tissue. Just the same idea as BMI. But then the really trained athletes tend to completely muck up those scales (I'm sure that I read somewhere that Redgrave comes up as obese on the BMI assessment because he's just got soooooo much muscle)

Also - to complicate matters more.... are shorter rowers likely to go at a higher rating? less distance covered up & down slide per stroke might make that likely - and won't that have an effect?

In crew rowing height matching is v important for getting the max out of every member - but I'm not sure the same holds in singles - which would be the equivalent to ergos. I have a feeling that some top class scullers have been quite short by rowing standards - which suggests that the link between height & performance, although definitely present, is weak....

*retreats to 'nerd' thread* :D
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Complex eh?

Post by PSims »

Now you know why I just post distance challenges, like Le Mans and 7 Wonders - cos it takes out the differences between people's strengths and puts the emphasis on:

- motivation
- planning your day to get the metres in
- that keep coming back for more effect
- beating the guy above you.

I know that isn't fair for all and there will always be differences, but we are such a diverse group it's hard to level it.

Nonathlon is probably the closest to achieving it as it uses age, sex and mixes up all distances. Sluggy has come close with the Summer Rollercoaster as well.
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Re: Weighting a challenge

Post by johnglynn »

JanetS wrote:Also - to complicate matters more.... are shorter rowers likely to go at a higher rating? less distance covered up & down slide per stroke might make that likely - and won't that have an effect?
I find this to be very much the case, I'm 6'6" and the highest stroke rate I've acheived with legs is 38 SPM.
Sub 6 foot rowers in the gym seem to be easily able to get into the 40's on any short distance.

Having said that the longer time under power of the stroke, the steadier acceleration of the stroke, the likely increased muscle mass and likely increased overall cardio performance, means that taller people have the advantage
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Developing models

Post by webberg »

Thanks for the feedback. Obviously a way to go yet.

On stroke rate I'm not sure that shorter people will apply higher rates. I rarely stroke over 30 and almost all my pieces are at 28 or less.

I would have thought that slide speed has more to do with fast twitch muscle fibre being present. Sprinters on the track have lots and you don't see short sprinters often.

On the numbers front Stan, I prefer to deal in concepts and let the numbers monkeys handle the trivia. I can however work the inverse proportional bonus game where those who do least get most. This has been a banking policy since the first caveman rented out his fire sticks. Sadly I'm still too far down the greasy pole.
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Re: Weighting a challenge

Post by Bangers »

Thomas W-P wrote:[

Anyway, they still need to get the energy from somewhere, but it stands to reason that a taller person has more mass and therefore a greater ability to store energy.

Probably all codswallop but it sounds impressive.
If the extra mass is fat rather than muscle there is cetainly potential energy, which is good once you get the mass moving (down the slide) unfortunately this isn't good news when it has to be stopped and brought back (up the slide). Also it's not so good if the person with long levers loses the advantages due to a belly (beer) getting in the way and limiting reach on the catch. :lol: I'm trying to be helpful really. I think Janet is right this topic is definitely destined for the Nerdies.
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Post by JanetS »

I'd tend to vote for leaving height out of the equation....

Once you've taken age, weight & gender into account that must go a long way to level playing - too far down that route and all you're comparing is perceived effort/ability to erg once blacked out.......

PS I'm 5ft 2
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