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Kyanzes
Amarr
Utopian Research I.E.L.
The ENTITY.
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Posted - 2008.05.02 15:54:00 -
[1]
Here's a chart that I've intended to use as a base of reference for my workout plan. Out of sheer curiosity I've decided to calculate those values myself and, to my surprise, they are way off.
The chart says that:
A guy weighing 175lbs and walking at 3mph for an hour will use up 278 kcal energy.
175 lbs = 79kg = 790 N
3 miles = 4827m
W = 790 N * 4827m
W = 3813330 J
1J = 0,2389 calories
3813330 J = 911004 calories = 911 kcal
So how come you only use up 278 kcal when, according to my calc, it should be 911 kcal?
I mean you do have to move your whole weight (79kg) and take it 4827m away, right?
What's the trick here?
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Kyanzes
Amarr
Utopian Research I.E.L.
The ENTITY.
|
Posted - 2008.05.02 15:54:00 -
[2]
Here's a chart that I've intended to use as a base of reference for my workout plan. Out of sheer curiosity I've decided to calculate those values myself and, to my surprise, they are way off.
The chart says that:
A guy weighing 175lbs and walking at 3mph for an hour will use up 278 kcal energy.
175 lbs = 79kg = 790 N
3 miles = 4827m
W = 790 N * 4827m
W = 3813330 J
1J = 0,2389 calories
3813330 J = 911004 calories = 911 kcal
So how come you only use up 278 kcal when, according to my calc, it should be 911 kcal?
I mean you do have to move your whole weight (79kg) and take it 4827m away, right?
What's the trick here?
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P'uck
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Posted - 2008.05.02 15:58:00 -
[3]
its been a while for me (over 15 years now...) but arent you calculating vertical movement there?
but in that case 911kcal would look low to me...
anyway... |
P'uck
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Posted - 2008.05.02 15:58:00 -
[4]
its been a while for me (over 15 years now...) but arent you calculating vertical movement there?
but in that case 911kcal would look low to me...
anyway... |
ReaperOfSly
Gallente
Lyrus Associates
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Posted - 2008.05.02 15:59:00 -
[5]
Where did you get the idea that work = mass * distance moved? Imagine a frictionless surface, and lightly pushing large weight. For an arbitrarily small amount of energy, the mass will move as far as you like (even if it takes a while to get there). |
ReaperOfSly
Gallente
Lyrus Associates
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Posted - 2008.05.02 15:59:00 -
[6]
Where did you get the idea that work = mass * distance moved? Imagine a frictionless surface, and lightly pushing large weight. For an arbitrarily small amount of energy, the mass will move as far as you like (even if it takes a while to get there). |
Kyanzes
Amarr
Utopian Research I.E.L.
The ENTITY.
|
Posted - 2008.05.02 16:03:00 -
[7]
Now I definitely want to know how to calculate this.  |
Kyanzes
Amarr
Utopian Research I.E.L.
The ENTITY.
|
Posted - 2008.05.02 16:03:00 -
[8]
Now I definitely want to know how to calculate this. |
P'uck
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Posted - 2008.05.02 16:12:00 -
[9]
Edited by: P''uck on 02/05/2008 16:15:37
i think its rather complicated, there is a lot of stuff to factor in.
i think at "3mph" you can neglect the resistance of air. afaik human beings cant really go a lot faster than 60km/h with their own musclepower because the resistance rises exponentially. and around 60 you hit a deadlock. sure, the tough guys can go up to 70 for very short amounts of time, but after that theyre kinda burnt out.
so in your example we can neglect the air and can purely concentrate on the energy the muscles burn. that means you have some sort of "base energy consumption" for running the heart, the lungs, in short the vital organs. afaik this base energy consumption would also rise through different factors. for example if youre 175lbs of pure trained muscles you probably will need MORE energy for your idling. since your example states "for 1 hour" this is probably a negligible amount too.
and then you have to calculate the energy the muscles use for moving your body forward.
and tbh that looks so friggin complex to me that i dont have the faintest idea how its done.
i bet for "home use" there are charts and oversimplified formulas, but the actual process is a major pita, i bet. |
P'uck
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Posted - 2008.05.02 16:12:00 -
[10]
Edited by: P''uck on 02/05/2008 16:15:37
i think its rather complicated, there is a lot of stuff to factor in.
i think at "3mph" you can neglect the resistance of air. afaik human beings cant really go a lot faster than 60km/h with their own musclepower because the resistance rises exponentially. and around 60 you hit a deadlock. sure, the tough guys can go up to 70 for very short amounts of time, but after that theyre kinda burnt out.
so in your example we can neglect the air and can purely concentrate on the energy the muscles burn. that means you have some sort of "base energy consumption" for running the heart, the lungs, in short the vital organs. afaik this base energy consumption would also rise through different factors. for example if youre 175lbs of pure trained muscles you probably will need MORE energy for your idling. since your example states "for 1 hour" this is probably a negligible amount too.
and then you have to calculate the energy the muscles use for moving your body forward.
and tbh that looks so friggin complex to me that i dont have the faintest idea how its done.
i bet for "home use" there are charts and oversimplified formulas, but the actual process is a major pita, i bet. |
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Sothis Antares
PBA Corporation
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Posted - 2008.05.02 16:24:00 -
[11]
you are calculating the work, which would be done if you would lift yourself up into the air :)
so the force you are causing isn't 790N. the force is based on your mass and your acceleration in horizontal
manners. this is basicly the first thing you have to calculate. and thats way less than 790N for average
people :) |
Kyanzes
Amarr
Utopian Research I.E.L.
The ENTITY.
|
Posted - 2008.05.02 16:30:00 -
[12]
So basically it would be true, in theory, for pull-ups. Well, thx anyways. It's not really that important, just wanted to see how is it calculated. |
Akita T
Caldari Navy Volunteer Task Force
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Posted - 2008.05.02 17:20:00 -
[13]
 Originally by: Kyanzes
So basically it would be true, in theory, for pull-ups. Well, thx anyways. It's not really that important, just wanted to see how is it calculated.
Experimental averages. There's way too many variables to actually calculate this.
If you're actually wondering where the "burned energy" is used up, here's a few things:
* acceleration/deceleration of each individual body part - makes up a vast majority of expenditure in "intense" conditions
* friction (body parts with eachother, body with the ground, body with the air) - mostly negligible
* thermal radiation (body needs to keep temperature stable, air is usually colder) - only relevant when you're mostly "idle", in case you pick up the pace the body actually needs to dump more heat than it is normally drained (hence, you start to sweat, and the evaporating water cools you off faster)
...and so on.
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Opertone
Caldari
Simtech Productions
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Posted - 2008.05.02 19:17:00 -
[14]
Edited by: Opertone on 02/05/2008 19:17:39
it is calculated by heart beat and time... and there are average values provided by medical studies
it's more of typical muscle calorie consumption x intensity x time
heart rate and time are direct inputs into calorie burning... and specific values are calculated depending on the weight and the age...
physical energy that your body consumes/produces is not the same the calories you burn in the process
best work out is when you can feel it, I never relied on charts in any way other than crude comparison
edit : this chart suggest that 2 hours walking 3 days a week is good for your health in any age!
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Nerogk Shorn
Caldari
Royal Hiigaran Navy
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Posted - 2008.05.02 22:10:00 -
[15]
I've heard somewhere that Muscle burns 3 times as many Calories than Fat by weight, and Brain matter burns 17 times more Calories than Muscle by weight. I've also read that 20-30% of the calories you consume go to maintaining your brain. There are really a lot more variables to this problem than we might think. 0_0 |
ReaperOfSly
Gallente
Lyrus Associates
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Posted - 2008.05.03 10:35:00 -
[16]
Originally by: Sothis Antares
you are calculating the work, which would be done if you would lift yourself up into the air :)
so the force you are causing isn't 790N. the force is based on your mass and your acceleration in horizontal
manners. this is basicly the first thing you have to calculate. and thats way less than 790N for average
people :)
Actually, he's not. If he multiplied it by g=9.8, THEN he would be. I have no idea where he got the equation W=m*d though. (Ooh look, WMD  ) |
Sothis Antares
PBA Corporation
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Posted - 2008.05.03 10:40:00 -
[17]
Originally by: ReaperOfSly
Originally by: Sothis Antares
you are calculating the work, which would be done if you would lift yourself up into the air :)
so the force you are causing isn't 790N. the force is based on your mass and your acceleration in horizontal
manners. this is basicly the first thing you have to calculate. and thats way less than 790N for average
people :)
Actually, he's not. If he multiplied it by g=9.8, THEN he would be. I have no idea where he got the equation W=m*d though. (Ooh look, WMD )
his assumption
Quote:
175 lbs = 79kg = 790 N
implies that he multiplied it by 9.8 (roughly). furthermore he didn't calculate with W=m*d, he was calculating with W=F*d. |
Lyn Quan
Caldari
State War Academy
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Posted - 2008.05.03 11:51:00 -
[18]
Quote:
. afaik human beings cant really go a lot faster than 60km/h with their own musclepower because the resistance rises exponentially. and around 60 you hit a deadlock. sure, the tough guys can go up to 70 for very short amounts of time, but after that theyre kinda burnt out.
Wait...60km/h ? Excuse me but where are you getting this data?
Or am I misunderstanding what you want to say?
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Amastat
Caldari
Omegatech
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Posted - 2008.05.03 12:09:00 -
[19]
Lol :P
Hey kids - stumped on homework? Do you have a deadline to meet on a essay your professer gave you?
NO PROBLEM
EVE-O Forums - the web's no. 1 homework help resource! (at least for science, math, and star wars trivia!) |
Imperator Jora'h
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Posted - 2008.05.03 13:12:00 -
[20]
Originally by: P'uck
i think at "3mph" you can neglect the resistance of air. afaik human beings cant really go a lot faster than 60km/h with their own musclepower because the resistance rises exponentially. and around 60 you hit a deadlock. sure, the tough guys can go up to 70 for very short amounts of time, but after that theyre kinda burnt out.
[nitpick]
You're a good bit over on maximum speeds. Fastest human sprinter ever did around 42-43 km/h. Fastest sustained speed is about 24 km/h (which would be about a 4 minute mile for the Americans here). Both of those are for someone in stellar physical condition.
Seems you need to revise your estimates down a bit
[/nitpick] |
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Imperator Jora'h
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Posted - 2008.05.03 13:21:00 -
[21]
If the OP wants to get very good answers to this I suggest The Straightdope Message Board (General Questions section). Currently they require a fee to post but you can post a few times for free to try it out (and soon they are going back to being totally free). You can get shockingly good answers there to just about anything you can think of (many posters there are experts in their field be it medicine, physics, etc.). Best forum for all around anything ever IMO.
No offense to the EVE-O posters. Lots of good and bright people here too. You just get faster and more complete answers to non-EVE stuff over there.
NOTE: The board I linked will get fussy if they think they are doing your homework for you and may just point you in the right direction to figure it out yourself. So phrase your question so it does not seem like homework or outright specify it is not homework. |
Sothis Antares
PBA Corporation
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Posted - 2008.05.03 14:17:00 -
[22]
Edited by: Sothis Antares on 03/05/2008 14:18:53
Originally by: Imperator Jora'h
You just get faster and more complete answers to non-EVE stuff over there.
well, the first answer in this forum was 4 minutes later. your post still hasn't got one answer yet. so don't mess around with
us eve-o posters :P
edited for messy english |
P'uck
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Posted - 2008.05.03 16:15:00 -
[23]
Originally by: Imperator Jora'h
Originally by: P'uck
i think at "3mph" you can neglect the resistance of air. afaik human beings cant really go a lot faster than 60km/h with their own musclepower because the resistance rises exponentially. and around 60 you hit a deadlock. sure, the tough guys can go up to 70 for very short amounts of time, but after that theyre kinda burnt out.
[nitpick]
You're a good bit over on maximum speeds. Fastest human sprinter ever did around 42-43 km/h. Fastest sustained speed is about 24 km/h (which would be about a 4 minute mile for the Americans here). Both of those are for someone in stellar physical condition.
Seems you need to revise your estimates down a bit
[/nitpick]
im sorry i was talking about cyclists, and probably shouldnt have said "pure muscle power". but in the end, theyre powered just by muscles, its just the mechanism that creates the forward drive is different.
but iirc thats only true for common bicycles and not those things you lie in. those probably can go even faster. |
Imperator Jora'h
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Posted - 2008.05.03 20:39:00 -
[24]
Edited by: Imperator Jora''h on 03/05/2008 20:39:13
Originally by: Sothis Antares
Edited by: Sothis Antares on 03/05/2008 14:18:53
Originally by: Imperator Jora'h
You just get faster and more complete answers to non-EVE stuff over there.
well, the first answer in this forum was 4 minutes later. your post still hasn't got one answer yet. so don't mess around with
us eve-o posters :P
Posters here do a good job to be sure and P'uck had the correct issue with the OP it seems so good job.
That other forum is still amazing. You can seemingly ask most anything and unless it is hypertechnical will likely get good answers in short order. Once it goes totally free in the next few weeks you could do worse than giving that place a spin.
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