Temperature even could _fall_ after exercise if sweating overcompensate. We're after all homeothermic animals, there's quite good system that keeps body temperature constant, and it could as well over-compensate as under-compensate.
(offtopic: and even when you're ill and have high temp, it's this system decides to increase metabolism rate for sake of fighting infection better. [For same reason you feel cold, so brain have ugre to assist this system in heating up body])

Also, it would not be valid to say that chemical energy expelled is same for both bad and good biker. I'm pretty sure it's different... assume there's newbie and good athlete inh cold winter wearing too light clothing. Athlete is more likely to survive as he have higher maximal amount of energy expelled (in this case, expelled as heat)

I would simply propose to assume that good biker can do more work than bad. That good biker have more "useful energy" than bad. Afterall OP are not interested in finding the heat and temperature, and probably aren't interested in biker's diet either.

Consider what _real_ data could be obtained from experiments:
Something like "Good biker can do up to Wg joules of work during one-hour race, novice can do up to Wn"
It alsone is enough if we don't care about heating of environment. You can only indirectly compute amount of chemical energy expelled from complex experiments measusing oxygen intake (and then computing to how much chemical energy it corresponds), and even that will not be precise.
It is also very hard to measure amount of thermal energy released, as you need to take into account heat lost through skin(and sweating), and with breathing.

As about Carnot engine, it would be like "approximating" electrical engine with Carnot engine - it's simply _not right_. Carnot engine it's engine that converts temperature difference to mechanical energy, and that's quite not how electrical engines or muscles works.

Completely empirical formulas or tables will work much better.

Really, tables with empirical data about bikers are simpler to work with than such "approximations".

Software-wise, it is very similar to car simulation, and in car simulator, amount of fuel spent is measured aswell. I suggest OP to google for car simulation and get some ideas of how it is usually done.

(ot: by the way, I rated you up back for that long & mostly useful post)

hehe thanx [smile].

About the carnot engine, you are right, that is why I discarded the idea almost as soon as I considered it. The basis of my idea is sort of treating the system as a blackbox and drawing an anology to a heat engine. The biker uses so much energy per cycle, some of it is lost to other non mechanical procesess. Where this lost energy goes and what shape it takes is not important to us, just that it leaves. We draw analogy to a heat engine.

Indeed, empirical results would be far more accurate but such would entail crocomire rethinking his methods and giving up certain ideas relating to power and energy (which may or may not be his wish). More importantly though, it would seem that such tables are rare, I couldnt find any online. If you can find any I wouldnt mind developing such an approach further.

The idea of fuel and treating the person as anologous to a car, it seems to be as much of an approximation as treating them as a heat engine.

[Edited by - Daerax on June 15, 2005 5:50:45 PM]

Quote:Original post by Daerax
hehe thanx [smile].

About the carnot engine, you are right that is why I discarded the idea almost as soon as I considered it. The basis of my idea is sort of treating the system as a blackbox and to draw an anology to a heat engine. The biker uses so much energy per cycle, some of it is lost to other non mechanical procesess. Where it goes and what shape it takes is not important to us just that it leaves. We draw analogy to a heat engine.

My idea is to treat the system as blackbox as well, blackbox that can do certain limited amount of mechanical work (we're not interested in heat produced by this blackbox, afterall.)

Quote:

Indeed, empirical results would be far more accurate but such would entail crocomire rethink his methods (which may or may not be his wish), such tables seem rare, I couldnt find any online. If you can find any I wouldnt mind developing such an approach further.

In either case, this stuff have to rely on empirical data for most things.

Quote:

The idea of fuel and treating the person as anologous to a car, it seems to be as much of an approximation as treating them as a heat engine.

not quite - at least good car simulations use empirical data for input, and it's done in such way that with other empirical data it would somewhat reasonably approximate biker.

In case of lack of empirical data, I would implement sort of like how stamina could be done in FPSes. It is not "accurate" but it have effects similar to those in real world.

Human can pull like 2KW for 5 or 10 seconds (total energy of 10 .. 20 KJ) and feel completely tired afterwards for some time. Or pull 500w for whole hour (1.8 MJ) and probably feel similarly tired for some other time(that could be significantly longer).

It would be like:
Let k is "subjective power" (we control it to accelerate or decelerate this thing). Let transmission keeps pedal RPM optimal. Let s is speed, let f is absolute value of all external forces such as drag and uphill/downhill gravity.

Then it could be approximated withn something like
if(stamina1<max_stamina1){
transfer=min(dt*k1, max_stamina1-stamina1);
stamina0-=transfer
stamina1+=transfer;
}
// if you feel like, you can implement yet another layer
if(stamina2<max_stamina2){
transfer=min(dt*k2, max_stamina2-stamina2);
stamina1-=transfer
stamina2+=transfer;
}
force=-f;
// use stamina1 if you haven't feelt like doing this stamina2 trick.
if(stamina2>0.0){
transfer=min(stamina2,dt*k);
force+=transfer/speed;
stamina2-=transfer;
}
acceleration=force/mass;

Above code tries to approximate conversion of different types of energy storage in the body.
Idea is that there are some energy reserve, nutrients readily avaliable ("stamina0") that doesn't recover during this session. All other types are recovered from there. As you may know, pathway of chemical-->mechanical energy conversion is quite complex. There is several buffers for various different chemical energy storages, etc. "transfer" it's how much of resources is converted from one 'layer' to other.

some info
Whole thing is of course very complex, there's whole 3 types of metabolism, but it can be approximated.

*************************
On energy:
Instead of storing how much energy are there in caek, we store how much of energy could be actually used after eating it. It makes sense, as caek have energy of m*c^2 but we aren't making antimatter bomb outta it[grin], we store how much energy can be obtained after eating caek.
Same there. If we are not interested in computing heat released, it makes sense to deal with part of energy that could be actually used. In this sense we can say that good biker "have more energy" than novice.

[Edited by - Dmytry on June 16, 2005 9:51:25 AM]

I see, and you adjust the bikers skills by messing with the stamina values... But how do you approximate the concept of performing worse as you get tired? For example, in my method I had in mind that as EConsumed -> EStored the value of efficiency would decrease proportionally from optimal. How does that method address this, by scaling transfer?

Quote:Original post by Daerax
I see, and you adjust the bikers skills by messing with the stamina values... But how do you approximate the concept of performing worse as you get tired? For example, in my method I had in mind that as EConsumed -> EStored the value of efficiency would decrease proportionally from optimal. How does that method address this, by scaling transfer?

Yes, it's also possible, once whole system is working.

if(stamina1<max_stamina1){
k1=c1*stamina0/max_stamina0;
transfer=min(stamina0,min(dt*k1, max_stamina1-stamina1));
stamina0-=transfer
stamina1+=transfer;
}
// if you feel like, you can implement yet another layer
if(stamina2<max_stamina2){
k2=c2*stamina1/max_stamina1;
transfer=min(stamina1,min(dt*k2, max_stamina2-stamina2));
stamina1-=transfer
stamina2+=transfer;
}
force=-f;
// use stamina1 if you haven't feelt like doing this stamina2 trick.
if(stamina2>0.0){
q=k*stamina2/max_stamina2;
transfer=min(stamina2,dt*q);
force+=transfer/speed;
stamina2-=transfer;
}
acceleration=force/mass;

speaking of efficiency, this is statement with some technical meaning: only small portion of energy of food you eat is converted to mechanical energy. In case you push wall, you spend your chemical energy with exactly zero efficiency. Your mechanical efficiency is below efficiency of typical engine, that's fact.

Quote:Original post by Dmytry
speaking of efficiency, this is statement with some technical meaning: only small portion of energy of food you eat is converted to mechanical energy. In case you push wall, you spend your chemical energy with exactly zero efficiency. Your mechanical efficiency is below efficiency of typical engine, that's fact.

Wow you act like you have more knowledge than God, that’s the only real fact I see here in all this mombo-jumbo and amd reading here.

Quote:Original post by Anonymous Poster

Quote:Original post by Dmytry
speaking of efficiency, this is statement with some technical meaning: only small portion of energy of food you eat is converted to mechanical energy. In case you push wall, you spend your chemical energy with exactly zero efficiency. Your mechanical efficiency is below efficiency of typical engine, that's fact.

Wow you act like you have more knowledge than God, that’s the only real fact I see here in all this mombo-jumbo and amd reading here.

Who are you to suggest as fact that there is somebody greater than God?