Working out percentages of splits on an erg
Trevor Chambers
embarassingly not only do I not know, but I can't find it either:
I need to know how to work out percentages of erg scores, for setting
squad training levels.
Eg Andy did 5549m in 20 min last week in an early-season test. I want
him to do a 20 min piece at 80%. How do I calculate a target split?
I know there's something raised to a cubic power involoved, and Anu
Dudhia's paper is great as far as it goes, but it doesn't go far
enough.
I knoe that the best way to do it would be to work off heart rates
rather than splits, and I do intend to assess AT's, but it's going
to take some time to do everybody so I need something in the meantime,
and anyway not everybody has a HRM.
Stephen Kiesling's book has a table of erg. splits broken down by
percentages, but is based on 2500m times, and 80% of that, for 20
mins, would be almost Andy's max.
Anyone got any ideas?
Trevor
Sudbury RC
Cwestmark
You could use power as your metric. Figure out what the power (watts) is for a
given split and go by percentages of that. I did this by pulling a series of
splits and then switching to watts and recording the relationship...generated a
graph of watts vs split. I'm not sure if you get a different graph for
different damper settings on the erg, though...you may want to check this.
But one thing...your "max power" for a 20 minute piece is a heckuva lot
different than your "max power" for a 30 second piece. I don't think most
people could hold "80% of max power" (meaning their absolute single stroke
maximum) for very long. I think I read somewhere that elite endurance athletes
can sustain power levels of about 65% of max for a relatively long period of
time (the length of a 2k race, for example). So really, heart rate is probably
the best measure...or if you don't have monitors to train with, guesstimate the
appropriate split based on power and see how it goes, then work the splits down
from there.
(This is one thing that has always bothered me about rowing...coaches say "75%
pressure" and then everyone interprets that in their own way. Other people
don't seem phased by that...must be bothersome to me 'cuz I'm an engineer. ;-)
)
Carolyn
Anu Dudhia
Assume power varies as the cube of speed.
Therefore speed varies as the cube root of Power, =(Power)^(0.333)
This means distance (in a given time) also varies as (Power)^(0.333).
If you want someone to do a piece at 80% (=0.8) of their maximum Power ,
their distance would be (0.8)^(0.333) = 0.928 of their maximum distance,
i.e. 0.928 x 5549m = 5149m
Split times are calculated as normal, eg for 5549m in 20min=1200secs,
split=1200/5549*500=108.1 s/500m = 1:48.1
For their 80% piece,
split=1200/5149*500=116.5 s/500m = 1:56.5
Next time I suggest you get your crews to make a note of the `average
power'
reading when doing their 20min maximum pieces. It makes life so much
easier.
Koster J.A.
Err....I feel that I should know the answer to this one, but rather
embarassingly not only do I not know, but I can't find it either:
I need to know how to work out percentages of erg scores, for setting
squad training levels.
Eg Andy did 5549m in 20 min last week in an early-season test. I want
him to do a 20 min piece at 80%. How do I calculate a target split?
I suggest you don't make your life unnecessarily complicated with all
this 'cube root to the power of Anu's shoesize'-stuff. Just use HR as a
rough guide to what's 100%, 80% etc. After a couple of workouts at 80%
you will know what the approximate split is, and you can use that as a
benchmark
to tell if a rower is over/underachieving. Of course, over a longer
period the rower will improve, so you need to check heartrates
regularily. Of course, this is not an accurate measure, just a practical
way of training (I think).
I calculate heartrate percentages by the following formula:
HR_percentage = Resting_HR+((Max_HR-Resting_HR)*Intensity_Percentage)
Where you have to train at a HR of approx. "HR_percentage" to achieve a
workout at "Intensity_percentage".
Another measure of training intensity is the Polar Exertion Count,
conjured up by a Canadian gentleman called Eric Banister: (taken from
Nunan - What's New nu...@enternet.com.au)
training impulse = training duration (min) x [(exercise h/r - rest h/r)
/ (max h/r - rest h/r)] x weighting factor (y)
where y(male) = 0.64e^1.92x
y(female) = 0.86e^1.67x
and x = [(exercise h/r - rest h/r) / (max h/r - rest h/r)]
As a guard against giving a disproportionate importance to long duration
activity at low heart rate levels compared with intense but short
duration
activity, the training impulse is weighted in a manner that reflects the
intensity of effort based on the classically described increase in blood
lactate in trained male and female athletes.
A3aan.
--
Don't attempt thinking for others before you can think for yourself.
http://www.cs.vu.nl/~a3aan/