weight and 10k time?

In article said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

You are not a controlled clinical trial.

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

rc5 said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

I have been trying to recall some estimates that floated here about pace per mile per pound. Your
single datapoint (assuming ALL OTHER FACTORS are equal) seems to show about 1second per mile per
pound (245seconds per 10K per 50pounds).

Any info on your "testing method"? How did you gain/lose 50pounds and maintain the same
fitness level?

--
Ed Prochak running faqs.orgrunning faqOpen ↗ netiquette psg.comemily.htmlOpen ↗
--
"Two roads diverged in a wood and I
I took the one less travelled by
and that has made all the difference."
robert frost

In article said:

rc5 wrote: I have been trying to recall some estimates that floated here about pace per mile
per pound.

Not a good metric.

It makes more sense to compare percentage weight reduction to percentage speed increase.

delta t =~ k delta w

where delta t = (t-t0) / t0 (units in seconds per mile) and delta w is (w-w0)/w0.

<k<1 is some sort of constant that measures the dependency between weight and speed.

In my limited experience, k =~ 1 unless you're pretty light, then it rapidly approaches zero as
you get towards optimal weight, then drops below zero. For heavier runners, it will be fairly
close to 1.

Quoted message said:

Your single datapoint (assuming ALL OTHER FACTORS are equal)

Incorrect assumption (-;

Quoted message said:

seems to show about 1second per mile per pound (245seconds per 10K per 50pounds).

It is not possible to make a meaningful comparison between two dependent samples. Even when you do,
you have no variance estimate for either sample (maybe the differences come from some source of
variation he didn't even think of)

Quoted message said:

Any info on your "testing method"? How did you gain/lose 50pounds and maintain the same
fitness level?

Exactly. And even if the "fitness level" is the same for both tests, how do we know that there
wasn't some other factor that influenced the picture (change in diet, change in sleeping habits,
change in work schedule, etc etc) ?

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

rc5 said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

Meaningless information without understanding your training and what makes up the weight.

--
Doug Freese "Caveat Lector" [email hidden]

"rc5" <[email hidden]> wrote in news:shcQb.592$ac.389169283
@news.nnrp.ca:

Quoted message said:

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

From Bob Glover's book, "The New Comptetitive Runner's Handbook"

Men For the 10K, add approximately 2 1/2 minutes per 10 pounds of extra weight. For the marathon,
add approximately 10 minutes per 10 pounds.

Women For the 10K, add approximately 4 minutes per 10 pounds of extra weight. For the marathon, add
approximately 20 minutes per 10 pounds.

-Phil

Quoted message said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

A 10K performance of 46:30 implies a relative VO2max of ~43.5 ml/kg/min. Assuming no change in
VO2max due to training (likely, but if you dropped the weight due to increased training, your LT
might now occur at a higher % of VO2max), your relative VO2max changes to roughly 50.8 ml/kg/min due
to the weight loss. This is because your O2 exchange, which does not change with a change in weight,
is now spread across fewer kg of weight, thus your relative VO2max goes up, while the absolute
VO2max is unchanged. The new VO2max inplies a new 10K time of about 41:45, not far from what you
actually got, or what Bob Glover would project.

Your results are reasonably close to what you might expect from basic physiology.

Lyndon "Speed Kills...It kills those that don't have it!" --US Olympic Track Coach Brooks Johnson

"rc5" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

Well, I lost 10 lbs in the last six months, and cut my 10km by 6 mins. Of course, it is hard to
factor the effect of training from the weight reduction.

If you are trying to figure out the price you are paying with the extra 30 pounds, consider the wear
and tear on your knees. When I was 190 lbs my knees were always swollen. They stopped being an issue
when I dropped under 160 lbs. Of course, once again it is hard to factor the effect of training from
the extra weight. Currently, I am trying to drop my weight to under 138 lbs, largely to further
reduce the wear and tear on my knees. I may go down as low as 130 lbs if it does me any good.

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

In article said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

You are not a controlled clinical trial.

He did not claim to be a controlled clinical trial. Why are you such a pain Donny boy? This is
USENET, lighten up. He is sharing a personal experience for whatever personal reason. Unlike you, he
is not interested in constantly enlighting the world. Besides, clinical trials deal with averages,
it may not apply to self described "biomechanically gifted" individuals such as yourself. I find
both anecdotal data and clinical data useful. Both tell me what is possible and serve to motivate
me. The only data I truly care about is whether I am getting healthier. I even find your posts
useful, I can't stop laughing at a self-described "biomechanically gifted" blowhard such as you.
Keep posting, you are a joke.

Quoted message said:

Cheers,

Sure, cheers to you too.

On Fri, 23 Jan 2004 11:50:36 -0500, "rc5" <[email hidden]>

Quoted message said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

I can't see how percentages would be relevant. What matters is the absolute amount.

--

Paul

My Lake District walking site (updated 29th September 2003):

paulrooney.netfirms.compaulrooney.netfirms.comOpen ↗

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

a pile of pseudo-mathematical rubbish. if you're going to castigate others for not applying
sufficient rigour to their theories, then perhaps you shouldn't be so sloppy yourself.

Quoted message said:

In article said:

rc5 wrote: I have been trying to recall some estimates that floated here about pace per mile per
pound.

Not a good metric.

It makes more sense to compare percentage weight reduction to percentage speed increase.

delta t =~ k delta w

where delta t = (t-t0) / t0 (units in seconds per mile) and delta w is (w-w0)/w0.

<k<1 is some sort of constant that measures the dependency between weight and speed.

In my limited experience, k =~ 1 unless you're pretty light, then it rapidly approaches zero as
you get towards optimal weight, then drops below zero. For heavier runners, it will be fairly
close to 1.

Quoted message said:

Your single datapoint (assuming ALL OTHER FACTORS are equal)

Incorrect assumption (-;

Quoted message said:

seems to show about 1second per mile per pound (245seconds per 10K per 50pounds).

It is not possible to make a meaningful comparison between two dependent samples. Even when you
do, you have no variance estimate for either sample (maybe the differences come from some source
of variation he didn't even think of)

Quoted message said:

Any info on your "testing method"? How did you gain/lose 50pounds and maintain the same fitness
level?

Exactly. And even if the "fitness level" is the same for both tests, how do we know that there
wasn't some other factor that influenced the picture (change in diet, change in sleeping habits,
change in work schedule, etc etc) ?

Cheers,

Donovan's approach comes at this problem from the empirical N=1 direction, which is unfortunate
because it arrives stillborn in his anecdotal quagmire. Curiously, he criticizes an earlier poster
for presenting anecdote as proof but resorts to the same approach in explaining the problem. His
linear dependence equation is fatally insufficient.

From the theoretical direction, it's clear to see that any case in which Donovan's k equals 1 must
obviously have other factors significantly affecting speed increases other than weight reductions.
Why? Because the only case in his model in which k can approach 1 is when you are working directly
against your own body weight, for example a vertical race. In a stair climbing race, if you weighed
5% less you can expect a time very close to 5% faster at the same power output level. Running is
mostly a horizontal affair and the speed dependence on weight is never 1 to 1 on this world.

A runner in motion is fighting most directly against a frictional force dependent on his weight in
the opposite direction to his velocity. This specific force, a reaction to the force the runner is
exerting on the ground to propel his body forward, is generally a fraction of his weight * gravity.
The coefficient of kinetic friction of running, which is highly specific to the technique & surface
he runs on, generally increases with velocity and is probably non-linear. Also, a runner's velocity
significantly attenuates at increasing magnitudes by aerodynamic drag.

To decrease the weight of a runner by 10%, the frictional force acting against motion at every
velocity will decrease by much less than 10% because you are only working against a fraction of your
body weight. Also there will be no significant decrease in aerodynamic drag. The end result is an
increase in racing velocity much smaller than 10%, likely on the order of 2-3%.

-Bill

On 24 Jan 2004 14:13:52 -0800, [email hidden] (William Paling)

Quoted message said:

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

a pile of pseudo-mathematical rubbish.

Yunno, I realise that Donny calls down all this misfortune upon his own head, but recently he's
been kicked by everyone from our favourite homophobic, Nike-wearing, treadmill-detesting, escapee
from god-knows-where, to this rather bright but somewhat self-satisfied person that goes by the
name of William.

JESUS! They're BOTH called 'William'! Could it be...?

In article said:

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

In article said:

Me,

140 lb, 10km, 42' 05" 170lb, 10km, 46' 30"

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

You are not a controlled clinical trial.

He did not claim to be a controlled clinical trial.

He said

It seems 20% increase on weight only resulting 10% decrease on 10k performance.

without qualifying that statement.

Quoted message said:

Why are you such a pain Donny boy? This is USENET, lighten up. He is sharing a personal experience
for whatever personal reason.

I didn't object to him doing so. I disagreed with the inference.

Quoted message said:

"biomechanically gifted" individuals such as yourself. I find both anecdotal data and clinical
data useful. Both tell me what is

Couldn't agree more!

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

In article said:

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Quoted message said:

where delta t = (t-t0) / t0 (units in seconds per mile) and delta w is (w-w0)/w0.

<k<1 is some sort of constant that measures the dependency between weight

^^^^^

Quoted message said:

Quoted message said:

and speed.

[snip]

Quoted message said:

From the theoretical direction, it's clear to see that any case in which Donovan's k equals 1

Do you understand what the < sign means in the expression

<k<1 ???

I'm not suggesting that there's any case where "k equals 1" attributable to weight reduction.
Therefore, your entire diatribe is based on a false premise.

I understand that you only get approximate locally linear behaviour, as I thought I made clear in my
post. If you don't understand this, pick up a differential calculus textbook.

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

Donovan Rebbechi said:

In article said:

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Quoted message said:

where delta t = (t-t0) / t0 (units in seconds per mile) and delta w is (w-w0)/w0.

<k<1 is some sort of constant that measures the dependency between weight

^^^^^

Quoted message said:

Quoted message said:

and speed.

[snip]

Quoted message said:

From the theoretical direction, it's clear to see that any case in which Donovan's k equals 1

Do you understand what the <

hmmmmmmmmm, less than but never ever equal? Yup I'm a math wiz.

Quoted message said:

sign means in the expression

<k<1 ???

I'm not suggesting that there's any case where "k equals 1" attributable to weight reduction.
Therefore, your entire diatribe is based on a false premise.

I understand that you only get approximate locally linear behaviour, as I thought I made clear in
my post. If you don't understand this, pick up a differential calculus textbook.

Yahoo, do I love mathematical trash talk. My K is bigger than your
K. 🙂

--
Doug Freese "Caveat Lector" [email hidden]

In article said:

Yahoo, do I love mathematical trash talk. My K is bigger than your
K. 🙂

That may be so, but your epsilon is approaching zero.

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

Donovan, Donovan, Donovan... backed yourself up into a corner?

Donovan Rebbechi <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

In article said:

Donovan Rebbechi <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Quoted message said:

where delta t = (t-t0) / t0 (units in seconds per mile) and delta w is (w-w0)/w0.

<k<1 is some sort of constant that measures the dependency between weight

^^^^^

Quoted message said:

Quoted message said:

and speed.

[snip]

Quoted message said:

From the theoretical direction, it's clear to see that any case in which Donovan's k equals 1

Do you understand what the < sign means in the expression

<k<1 ???

In a real world horizontal running situation, k will never even come close to approaching 1. And you
know you're in trouble when you protest over an infinitesmal insignificance...

🙂 I mentioned that you were sloppy, and here in your own words is
what you snipped out from your comment hack job:

"In my limited experience, k =~ 1 unless you're pretty light, then it rapidly approaches zero as
you get towards optimal weight, then drops below zero. For heavier runners, it will be fairly
close to 1."

Shaky ground to be standing on, better grab hold of that heavy calc textbook you've been
misunderstanding. Better yet, grab the physics textbook too because it'll anchor you better to
reality. No further comment necessary here, the contrast between this nonsense and my original
response speaks for itself.

Quoted message said:

I'm not suggesting that there's any case where "k equals 1" attributable to weight reduction.
Therefore, your entire diatribe is based on a false premise.

In other words, you've attempted to approximate the complex system of the human body while running,
taking into consideration training effectiveness at all different weights, throwing in some baseless
minimum weight level before the body starts getting slower with marginal weight loss, taking into
consideration the balance between body fat % and lean body mass at all different weights, and
attempted to model this all with "delta t =~ k delta w." Nice try buddy, but Occam's Razor doesn't
cut in the incorrect direction. You should name this equation "Donovan's Attempt at Math" because it
really is cute. Sometimes a limited amount of information can be more dangerous than all the facts.

Quoted message said:

I understand that you only get approximate locally linear behaviour, as I thought I made clear in
my post. If you don't understand this, pick up a differential calculus textbook.

Cheers,

You understand very little, obviously. Do they teach you to obfuscate reality with nonsense
nowadays? You're simply wrong, stop spreading your pseudo-science and deal with it.

-Bill

Donovan Rebbechi said:

In article said:

Yahoo, do I love mathematical trash talk. My K is bigger than your
K. 🙂

That may be so, but your epsilon is approaching zero.

At least it's positive albeit small. Besides I'd rather be RHOing along anyway. The Greek alphabet
provides such a rush. That's rush as in numbers not as Rush Limbaugh with some magic caps.

--
Doug Freese "Caveat Lector" [email hidden]

In article said:

TopCounsel said:

My guess is that if you graphed times vs. weights, you'd end up with a parabola which shows high
times at both too-low weights and too-high weights. Obviously, you'd strive for the "minimum"
point on the curve.

To "derive" a precise equation is probably impossible, but if someone plotted hundreds
(thousands?) of data points (T vs. W), you'd get a very close approximation of the curve from
which to state your "formula." It could prove interesting to plot delta T vs. delta W also, as
Donovan has suggested.

This reminds me race prediction charts, makes great reading but with large volume averaging they
are individually useless.

Yep. You really need to take the "experiment of one" approach to work out the "ideal" weight.
At least until someone works out what the "all other things" are that are both important, yet
not "equal".

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗

In article said:

Donovan, Donovan, Donovan... backed yourself up into a corner?

Quoted message said:

Quoted message said:

Do you understand what the < sign means in the expression

<k<1 ???

In a real world horizontal running situation, k will never even come close to approaching 1.

The prevailing belief among exercise physiologists is that the energy cost of running is linear in
bodyweight, with the line going very close to the origin. (I have some hard data that shows this is
true for walking, but not for running unfortunately) Because of this, most "energy cost of running"
tables are weight-normalised (or based on a line through the origin).

Air resistance is only a small portion of total energy cost. Horizontal friction is probably close
enough to linear not to matter. Most of the energy cost of running is due to vertical forces anyway.
So you will end up with a fairly high k, much higher than the 0.2-0.3 value you postulated.

Quoted message said:

protest over an infinitesmal insignificance...

🙂 I mentioned that you were sloppy, and here in your own words is what you
snipped out from your comment hack job:

"In my limited experience, k =~ 1 unless you're pretty light, then it rapidly approaches zero as
you get towards optimal weight, then drops below zero. For heavier runners, it will be fairly
close to 1."

Shaky ground to be standing on, better grab hold of that heavy calc textbook you've been
misunderstanding.

I'd rather be me than you right now (-;

Quoted message said:

In other words, you've attempted to approximate the complex system of the human body while
running, taking into consideration training effectiveness at all different weights, throwing
in some baseless minimum weight level before the body starts getting slower with marginal
weight loss,

There is a "base" for this minimum weight level". The point of diminishing returns comes where it is
impossible to get lighter without losing useful lean mass.

Quoted message said:

Sometimes a limited amount of information can be more dangerous than all the facts.

Exactly. Now run along and get yourself an exercise physiology book.

Quoted message said:

You understand very little, obviously. Do they teach you to obfuscate reality with nonsense
nowadays? You're simply wrong, stop spreading your pseudo-science and deal with it.

oh, the irony.

Cheers,
--
Donovan Rebbechi pegasus.rutgers.edu~elflordOpen ↗