Sprint Geezer wrote:
Which number?
As you correctly identified, the per-unit-body-mass is essentially a measure of speed.
I totally agree that the measure of Cal/kg/min is interesting. I get that. It's just that as P.Whelan pointed out, you've arrived at it in a circular fashion.
Bekele's 0.38 is simply 10km/26.29min
Solinsky's 0.37 is simply 10km/26.98min, etc.
Weight (mass actually) doesn't enter at all. As such, you really can't infer anything mass-related based on this quantity, due to the initial assumption that the basic rate (by distance, not time) of energy expenditure is 1 Cal/kg/km.
You need something more.
lucKY2b he has addressed the heat production issue, get with it.
In the 1980s, Allen Just ran a 2:18 marathon at 180 pounds. He was a SoCal guy, looked like a world-class decathlete--big arms and all. That's 5:16 pace, which means that he ran eight straight 5Ks in about 16:18 each and then 2K more at that pace. I know it's not actually meeting the requirements here, but I'm pretty sure that if he'd gained 20 pounds--especially if if was mostly muscle--he could still have run sub-16:00 pretty easily. Don't you think?
haha YO wrote:
kent tekulve wrote:And I can guarantee that somebody has...
Prove it. Should be easy enough if it has happened.
You must really be a moron. I've done it myself when I was out of shape. I've also known others who have. What a talentless moron with no imagination you must be...
J.O., thanks for the cajoling, but I assure you, I'm totally "with the program". But if sprint geezer insists there is something to his contrived power/unit mass quantity, then it must be glaringly exposed. I (and P.Whelan) were trying to point out that his ratio isn't just "essentially" speed, it is "identically" speed. As such, it has no merit regarding weight. It's already well understood that big guys will have more of a heat dissipation issue, but this back of the envelope analysis certainly tells us nothing about that. What his analysis tells us is that the only way to determine what one's "best event" is is to run a bunch of race distances and compare the resultant speeds to the world's best, and see where that ratio is largest. I think that's all that you can infer from this.
The other thing that come out of this is that if one assumes that energy expenditure/unit mass/unit distance is the same for all runners (which it's not), then the runners that maintain the most power over the requisite time for the least mass will run fastest. Shocking, I know.
Ran with a guy who was 6'7 and had run under 16. Some races apparently (only know this because of him) have a Clydesdale division, and he raced in those. The requirement for that is >200lbs. He was about as far from fat as possible; he was just reasonably muscular and 6'7. I bet he weighed more when he ran faster, even.
Here's something else that comes to mind, maybe someone knows...
Say there are 2 runners of the same gender, having identical body mass and identical "running efficiency" (that is, having identical energy expenditure per unit distance over say, 10k), but of greatly varying height, maybe 5'6" and 6'0", will one of the two run the 10k faster than the other, even though they both theoretically expend the same amount of energy over the 10k? i.e. is it intrinsically more efficient to have, say, a longer stride?
And for lucKY2b--I don't know why you keep returning to the 37 and 38 per unit body mass figures--they were only included incidentally, and I acknowledged that they were measures of speed.
Nobody is arguing with you, that is why you don't appear to be "with the program".
OK, fine. In the end, it does seem like, if it were purely a heat dissipation issue, then I agree that a thicker person would have a disadvantage. Note that I say thicker, because surface area to weight ratios don't directly correlate with height. A tall person doesn't have the same proportions of a shorter person, so one can't just simply apply scaling arguments.
I've not seen a systematic study that proves height has a correlation to efficiency, granted I'm no expert. The empirical evidence (at least for marathon distances) suggests the opposite. Not that there aren't outliers.
One formula for calculating body surface area is this:
Body Surface Area = ( ( Height(cm) x Weight(kg) ) / 3600 )1/2
(The Mosteller formula)
That is, the square root of (height times mass divided by 3600)
For Solinsky at 73.2kg and 185cm, that gives about 1.94 square meters.
For Bekele at 54.5kg and 162.5cm, that gives about 1.57 square meters.
I know some cooling comes from breathing, but let's ignore that for the moment, and use body surface as a measure of cooling, assuming the same cooling efficiency over a unit area.
Using the 10k energy expenditure rates originally calculated for these two guys, the ratio of Solinsky's energy expenditure rate to body surface area is 27.11/1.94, or 13.97, while Bekele's is only 20.53/1.57, or 13.08
13.97 vs 13.08 I know there are some assumptions, and I don't know at what level the difference might manifest or become significant, but it's basically 13 vs 14, or a 7.7% difference.
I imagine Geb's is pretty much the same as Bekele's.
I guess the question is whether or not this difference does manifest in a race, and if it does, at what point and to what extent. My feeling is that it absolutely manifests in the marathon, which is why you'll never see Solinsky running it--or if he did, I think he'd have to pick a cool one.
I would not be surprised if it manifests over the 10k distance under certain conditions and at that rate of energy expenditure. Solinsky is an interesting experiment at the 10k--at the 5k, I don't think he'd ever have a problem. I'll be interested to see what he can do with his 10k time, and I am shocked that he has run as fast as he has--I would have thought that he'd have burnt up going that fast.
I have had one too many Irish Carbombs for this thread.. f*ckinA.
hmmm, something i could actually "beat" solinsky at??? haha. fyi, currently down to 172....I was 190 when i ran 13:58 (ironically TS won the heat- kicked my butt!) in 2nd heat of mt sac....not sure what that calc's out to but must be up there... 29:03 at 175. 1:04:55 at the same weight. oh, and i'm 6'2" for equation purposes.and whoever said CS was only 151, he's 164, horses mouth.cheers, dude-----------------------------------------------------------
drivel wrote:
Bryn_R wrote:Who was the US guy who did some semi-quick times whilst wearing board shorts? I imagine he'd be up there.
Be interesting what Webb's peak weight was but probably just too small.
Christian Hesch? Hes closer to 180 than 200.
brah boi wrote:
i run with a guy in australia who weighs 85kg/187lb n he has run 14.41 for a 5km.I think thats very impressive.Especiialy considering his very capable of running under 14.20
That is true, that'd be Vince Shepherd
14.41.34 Vince Shepherd N 031088 Sydney 28-Jan-10
Fairly new to running, a super talent and was on a massive improvement curve when he ran this, but has had an achilles injury ever since. Not a shock, he is a big guy!
kent tekulve wrote:
You must really be a moron. I've done it myself when I was out of shape. I've also known others who have. What a talentless moron with no imagination you must be...
I'm not a moron, I'm a realist. Please post your race results as well as a picture of you from when you ran it since that will be the best way now to estimate your weight. Any random jackass can say they did it, put up or shut the f*** up.
Sprint Geezer wrote:
Using the 10k energy expenditure rates originally calculated for these two guys, the ratio of Solinsky's energy expenditure rate to body surface area is 27.11/1.94, or 13.97, while Bekele's is only 20.53/1.57, or 13.08
Very interesting discussion, treating the body as essentially a heat engine. Just a couple of additional complicating factors:
1) Running isn't only about dissipating spent thermal energy, so this discussion is limited to the thermal exhaust side of the equation of state. Metabolic rates and the ability to dispose of biochemical "waste" also dictates energy consumption rates.
2) It is assumed, that we race at essentially the highest temperature that our bodies will allow us to function over the requisite distance, and that that temperature is the same for all individuals.
haha YO wrote:
Not buying it. Again, distance runners tend to exaggerate weights beyond belief. Hell, there are people on here who call Alan Webb fat. I am not buying for a second that a 14:22 guy weighed 200+. 180, yeah. To most distance runners seeing a 6'4" guy weighing 180 would make them think of a 200 pound runner.
Just because you don't believe it's true doesn't mean you are right. Provide some evidence to support your case, and that can refute mine. I provided an example to refute your conclusion and you challenged that evidence on a belief. You must take your advice from the GOP.
Nick Ekel of Wyoming ran a 30:32 XC 10k at Salt Lake weighing 193 lbs, and a 30:25 10k at MT SAC weighing 190.
So you're trying to be somewhat scientific but you actually think you can burn calories? What are you in middle school?
I'm still trying to decipher your question...
yes, I understand that "calorie" is a somewhat antiquated unit of energy, if that's what you were getting at...
If I ever said "burn calories" I was obviously speaking colloquially, but thanks for that needlessly pedantic criticism.
lucKY2b wrote:
Running isn't only about dissipating spent thermal energy, so this discussion is limited to the thermal exhaust side of the equation of state. Metabolic rates and the ability to dispose of biochemical "waste" also dictates energy consumption rates.
Well it's about time we had an intelligent discussion on the subject.
Now tell me about those biochemical "waste" products?