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Re: WAARC - March 2013 - 2km

Posted: Sun Mar 10, 2013 1:06 pm
by AlanS
It's tight at the top, and without having to do anything, millie has moved to the top!
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Re: WAARC - March 2013 - 2km

Posted: Sun Mar 10, 2013 2:29 pm
by billwright
Great stuff Millie. =D> =D>

Mikkel - thanks. I would like to go sub -7 this season but time is running out. I reckon 7:08 is within my reach so sometime in April I guess.

Bill :fswink: :fswink:

Re: WAARC - March 2013 - 2km

Posted: Sun Mar 10, 2013 4:43 pm
by Shang-Chi
Strange and interesting: As Bill and I rowed faster, it is Amanda who goes to the lead, after being 2nd.:?: :? Otherwise there's not considerable change, other than Alan loses 3 points for not being faster than Bill who gains points with a new better time. Then you would think that only they would change places. :-k

And my 21.3 sec. faster time didn't change one bit for me. :!: :?: :lol:

Re: WAARC - March 2013 - 2km

Posted: Sun Mar 10, 2013 7:05 pm
by billwright
Is there a new criterion now Mikkel? Gender? Or was that always there?

Bill :fswink: :fswink:

Re: WAARC - March 2013 - 2km

Posted: Mon Mar 11, 2013 12:55 am
by Shang-Chi
billwright wrote:Is there a new criterion now Mikkel? Gender? Or was that always there?
No that's rather new, and I think I was the one who asked the question if we could run them together as there were only 2-3 women taking part. :mrgreen:

Re: WAARC - March 2013 - 2km

Posted: Mon Mar 11, 2013 1:28 pm
by strider77
Only just caught up with the weekends results-well done Bill-very close betweeen us-my next go this Thursday, hoping for a modest improvement.

Millie, I think you deserve to be at the top, nice rowing =D>

MInd you Bill, Mikkel and me will not make it easy to stay there :lol: :wink:

Re: WAARC - March 2013 - 2km

Posted: Tue Mar 12, 2013 7:33 pm
by Mike Channin
I think it is fascinating how things are changing around with it being so close at the top. I'll have to seriously up my game to be able to join in the fun...

One quick question, Alan - how have you applied the 15% bonus? I suspect it should be applied as a power bonus, rather than raw time. Haven't had chance to see if that is how you did it...

Well done all - will do my best to catch up soon.

Re: WAARC - March 2013 - 2km

Posted: Tue Mar 12, 2013 8:44 pm
by plummy
I decided I only wanted a short paddle tonight (and wasn't too sure if it was a good idea) but after a short 10 mins warm up I set for 2k to give my legs a little stretch and to start to re-learn higher stroke rates. It took a while to get going but I managed a half respectable 7:26.1 @ 29SPM.

Weight measured at 69.2kg

Re: WAARC - March 2013 - 2km

Posted: Tue Mar 12, 2013 11:15 pm
by Mike Channin
Well done Plummy - after what you've been through, that took some guts!

Making me feel positively lazy for dodging this one so far...

Re: WAARC - March 2013 - 2km

Posted: Wed Mar 13, 2013 3:40 am
by millie
Thanks Bill and Mikkel (and great rows =D> ) for catapulting me into the lead without me needing to lift a finger :fsbgrin: That was the easiest 2k ever :lol:

My adjusted time is way quicker than the rest of you though - maybe the 15% is a bit high?? the rest of you will want me back in a female leaderboard at this rate :lol: If I have a spare hour or two during March I'll have a look at some results from e.g. the Crash B's and normalise them for age and weight and see if there is a more scientific estimate we can use based on empirical results..(yes I'm a geek)... I know for OTW we use 'prognastics' but they only look at gender, LWT v HWT and u19 v u23 v Open so won't be much use. Likewise Nonathlon scores would have gender and age but only LWT v HWT - and there's a big difference between a 66kg HWT like me (I think I'll have to join Mike as a 'fat LWT' :) ) and an 86kg HWT....

And Plummy ^O^ ^O^ I can't believe you did a 2k so soon after rowing as far as you did on the weekend - very impressive!

Anyway, it is good fun being able to compete with you men :fsbgrin:

Re: WAARC - March 2013 - 2km

Posted: Wed Mar 13, 2013 3:45 am
by millie
millie wrote:If I have a spare hour or two during March I'll have a look at some results from e.g. the Crash B's and normalise them for age and weight and see if there is a more scientific estimate we can use based on empirical results
Well that plan has failed already - crash b results don't show weight, whereas the Manchester results did, but not as many rowers so data won't be so good...

Re: WAARC - March 2013 - 2km

Posted: Wed Mar 13, 2013 9:56 am
by AlanS
Thanks for the entry, plummy. I'll update the leaderboard soon.
Mike Channin wrote:One quick question, Alan - how have you applied the 15% bonus? I suspect it should be applied as a power bonus, rather than raw time. Haven't had chance to see if that is how you did it...
I applied it as a 15% bonus to raw time. So in the same way the weight factor may work out to be 0.97 for a slight LWT, for example, I have applied the gender bonus as 0.85.

I wouldn't know how to implement it as a power bonus in terms of spreadsheet calculations. If you could give me some pointers, I could give it a try and see if it produces results that feel more right, perhaps.

Re: WAARC - March 2013 - 2km

Posted: Wed Mar 13, 2013 11:19 am
by GrantR
Power relates to time as a cube root, so you can apply millie's correction as adjustedtime = rawtime * (0.85)^(1/3)

so her 7:39.2 adjusts down to 7:15.0

likewise I imagine all the age and weight corrections should be applied to power instead of time, and can also be applied in the same way, by cube rooting the scale factor. Or just smoosh all the corrections into one term together then cube root it once.

Re: WAARC - March 2013 - 2km

Posted: Wed Mar 13, 2013 12:20 pm
by Mike Channin
Millie - welcome to the 'Fat Lwts' club ;-)

You're hitting the same issue I did when I tried to look at weight normalisation - the undisclosed and variable weights of the Hwt competitors wrecks any attempt to tease out a correction metric. I was going to try assuming a notional fixed weight for elite Hwts, and see if that gave anything usable.

That said, I think the 15% _power_ bonus for gender should work out fairly close.

And I second everything that Grant says. Hits the nail on the head, as to why raw linear adjustment ends up over-compensating, because rowing performance is a factor of power, which has that cube root relationship. This is the conversation that we were trying to have on the Weight adjustment thread (and maybe we should continue over there, or start a new one, rather than divert Alan's competition thread too much).

Alan, in terms of the normalisation, convert everything to power, apply the corrections, and then convert the resultant power back into a time to get a power corrected figure. (This is also how I normalise performance for form calculation across multiple distances). Again, looks like it might be worth discussing on a separate thread.

Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 11:40 am
by AlanS
Thanks for the info, Grant. And good to see you back posting.

I don't think everything should be converted to power, as that would probably change the basis under which C2's age and weight adjustments are designed to operate.

http://concept2.co.uk/rns/adjustment

As you'll see, the weight adjustment is already ^ (2/9), which looks close enough to ^ (1/3) to make me think it's already kinda doing the same thing. And age adjustment is just a proportionate (to 2km) amount of time to be added or subtracted.

But I will try and apply the gender adjustment as per Grant's post and see what happens. Sorry millie... :fswink:

Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 11:46 am
by AlanS
OK, with Mike and Grant's tweak of the female power adjustment, millie drops down to 3rd, and Bill finds himself in the lead.

And although plummy enters at position 5 of 6, he does have the fastest weight adjusted time.
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Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 12:41 pm
by Shang-Chi
How fast do I need to row :?: If 6:40 isn't enough I won't bother. :lol:

Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 12:44 pm
by AlanS
6:40 wouldn't be enough at your current weight, Mikkel. If you could lose a couple of kilos and do a 6:40 it might be very close. :fssmile:

Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 1:07 pm
by GrantR
Hmm I think I made a typo. I was just double checking using the pace calculator and it's displayed wattage, and my suggested corrected time of 7:15.0 is actually 18% higher in power than 7:39.2 (272.5W vs 231.3W). But instead of using (1-0.15)^(1/3) = 0.947268 as the time correction factor, it should be (1/(1+0.15))^(1/3) = 0.954481, giving 7:18.3 (266.6W) which is the desired 15% higher. My bad, sorry!

None of this would make my score look any good if I tried it :) I haven't touched the rower for 2 months (was too busy at work for most of january/february, then had a bit of a cough. But did manage to have a row the last two Mondays! I'm a good 25-30 watts off pace versus 2 months ago though :( But with another week or so of catching up again I'll be up for putting some rows in before the month is out.

Re: WAARC - March 2013 - 2km

Posted: Thu Mar 14, 2013 1:42 pm
by Mike Channin
I think that 6:40 for Mikkel would move him to equal top on 16pts, but I suspect other times may change before the end of the challenge.

The current C2 weight adjustment is for a notional equivalent speed in a boat and is not designed as a normalisation function. The age adjustments seem to be a simple linear adjustment, and I don't think they scale well when you get to the higher levels of performance in older rowers, so none of these are comparing like with like. I think that if you were doing this for accurate normalisation, all the functions would be defined in terms of power, but that isn't the rules that Alan has kindly agreed to run. It was only important re: the gender adjustment because, as you can see, applying 15% linearly gives a run-away advantage compared to the power scaled version. (This same kind of run-away seems to happen on the age adjustment, hence the reason I believe the scaling is too simplistic, but it is what it is, so let's use as is.)

As long as the adjustments used achieve their goal, which is to allow a set of disparate individuals over a range of times to compete and find motivation, then they're doing their job.

Re: WAARC - March 2013 - 2km

Posted: Fri Mar 15, 2013 12:02 am
by millie
Well I suppose I'll just have to row a bit faster then :wink:

Had second go at this today, was aiming for '97.5%' effort this week, to hopefully set me up for a flat out effort in the next couple of weeks. Aiming for 1:54 pace this time, managed a time of 7:35.7 @ 31 spm (average pace 1:53.9 :) )

Despite not being a completely flat out effort, I did still encounter the HD demons at around 1000m, questioning whether I really wanted to do another 1000m at a pretty fast pace. I toyed with them, and made them think I would stop at 1500m, but then I kept going and made it to the end with a better sprint finish than my '95%' effort last week.

But I don't think it will help my placing on the leaderboard :cry:
Especially since I'm a bit heavier this week - 66.0kg

Re: WAARC - March 2013 - 2km

Posted: Fri Mar 15, 2013 10:50 am
by GrantR
Nice improvement, Millie! :)

and pfff I have no idea what i'm talking about regarding that 15% adjustment. I realized this morning it probably actually is my original 0.85^(1/3), not (1/1.15)^(1/3) but my attention span isn't long enough to remember what math I did 24 hours ago, so I won't mention it again due to a high probability of changing my mind again tomorrow. :)

Re: WAARC - March 2013 - 2km

Posted: Fri Mar 15, 2013 1:49 pm
by AlanS
Mike Channin wrote:I think that if you were doing this for accurate normalisation, all the functions would be defined in terms of power, but that isn't the rules that Alan has kindly agreed to run. It was only important re: the gender adjustment because, as you can see, applying 15% linearly gives a run-away advantage compared to the power scaled version. (This same kind of run-away seems to happen on the age adjustment, hence the reason I believe the scaling is too simplistic, but it is what it is, so let's use as is.)
I don't mind changing the way the adjusted times are calculated, as long as it is an improvement and has some basis in reality (i.e. not an entirely made up algorithm). I'll keep things as they are for this season, but next season is up for debate. Indeed, I posted in another thread yesterday about possible changes for next season, so feel free to continue this discussion there.

viewtopic.php?p=111599#p111599

And well done millie, nice effort. =D>
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Re: WAARC - March 2013 - 2km

Posted: Fri Mar 15, 2013 2:38 pm
by Shang-Chi
If you say something about not bother doing it because you'll need 6:40, well then you kind of have to try. Read this and weep happy tears:

6:38.5 2000m 29spm HR164 @1:39.6 Cal/hr1518 Watt354
Splits were:
1:19.3 _400m 31spm HR150 @1:39.1 Cal/hr1536 Watt359 Good start :D
1:19.3 _800m 30spm HR155 @1:39.1 Cal/hr1536 Watt359 Feeling okay 8)
1:19.9 1200m 29spm HR167 @1:39.8 Cal/hr1509 Watt351 Now it's beginning to hurt =P~
1:20.7 1600m 30spm HR170 @1:40.8 Cal/hr1473 Watt341 Loosing a little :roll:
1:19.2 2000m 30spm HR178 @1:39.0 Cal/hr1541 Watt361 1st. 100m I did 10 strokes in @1:40 and then sprint, hitting 1:36 :twisted: \:D/ =;

Weight 86.7 (not enough kg. lost, I guess :roll: But still better than nothing)
Age 48 :mrgreen:

Re: WAARC - March 2013 - 2km

Posted: Fri Mar 15, 2013 3:37 pm
by billwright
Nice one Mikkel =D> =D>

Bill :fswink: :fswink: