I have to burn 1,000 calories a day?

quiksylver296

Did the OP ever come back?

blambo61

Aaron_K123 wrote: »

JerSchmare wrote: »

Aaron_K123 wrote: »

blambo61 wrote: »

Aaron_K123 wrote: »

kakaovanilya wrote: »

I am surprised. I thought the faster you walk, the more calories you burn. Good to know

The faster you walk or run the more calories you burn per unit time but not per mile. The faster you move the faster you complete a mile and therefore the less time you are exercising if you only run one mile. I mean who burns more calories? Someone who walks a mile in 30 minutes or someone who sprints it in 5. Well, the person who took 30 minutes because they are measuring their caloric burn over 6 times the amount of time. If you compared their burn over just 5 minutes then yes the person sprinting burn a lot more than the person walking slowly.

Sorry but it doesn't work that way. If there were no up and down motion due to running vs walking and you ran in a vacuum so that there was no wind resistance, walking or running the same distance would use the same amount of energy (assuming the boy doesn't heat up more running). Energy usage is a function of distance traveled and not speed all those other things being equal. In real life, running does have up and down motion, your going faster which produces more drag which increases proportional to velocity squared, and your at a higher power level so you internally will heat up more. Running a mile will absolutely use more calories than walking. The faster you go for the same distance, the more energy you will burn primarily due to the added wind resistance, internal heating, and up and down motion. Remove those things and it would be equal. The walk will NEVER use less energy than the faster run.

I get that if you are talking about a machine that is built to travel a certain distance that difference that the machine that travels that distance faster will be less efficient than the machine that travels it slower due to drag and therefore will expend more energy in doing so. That I agree with. But are you sure that principle applies to a human whose engine is a biochemical one? For a machine working twice as hard will burn more than twice the amount of fuel. For a body though I am not sure that working twice has hard will burn twice the calories. I mean, ones heart rate can only go so high and I don't think the relationship between effort, heartrate and caloires burned is a linear one.

Picture this scenario. I walk a 26 mile route with an elevated heartrate and it takes me 12 hours. After I lie down and sleep for the remaining 12 hours. My clone ran the same route it and it took them 6 hours, they then lie down and sleep the renaming 18 hours. You are saying that their caloric burn above their 24 hour rate if they had not been active at all would be more than twice as much as mine? Doesn't the amount of time I have an elevated heart rate for (12 hours vs 6 hours for my doppelganger) matter at all?

I have a heart that elevates in rate associated with my metabolic rate elevating due to activity to dispose of excess carbon dioxide. The amount of time I am in that elevated state has potentially more effect than how elevated it gets. In otherwords a person with a bpm of 110 working for 2 hours will likely burn more calories than a person with a bpm of 150 working for 1 hour. Does it matter if the first person ran the same distance as the second person to achieve that bpm elevation over a longer period of time?

I'm not sure that I am correct, maybe you are right....but I'm not so convinced it is as cut and dry as a comparison you are making it out to be. I certainly don't think your comment deserved being "woo'd" though you may be correct.

I’m unclear as to your point, although I read it 3 times.

But, in many studies, they have compared running and walking, and speed. I have also done my own study on myself. Distance is all that matters. The effort is the same whether it’s 1 hour or 3 hours. What seems to be the main factor is distance. If I run 5 miles in 30 minutes, and it takes you 2 hours, we both burned around the same amount. I know it may not seem like it, but in many studies of running, it’s about the same. Walking only burns slightly less than running and that is because when you walk, one foot is always on the ground, so the effort is less than running where there are small periods of time where both feet are off the ground. But, while the effort is less for walker no, it’s only slightly less.

Point I was trying to make is I'm not sure one can simplify a body moving over a distance as a point mass moving in a flat line over a set distance at different speeds and then factoring in drag. I think the difference in calories burned going from a bpm of 80 to 120 is much greater than pushing that 120 further to 160. So although yes of course the harder you work the more calories you burn per unit time I do wonder that if you got your heartrate up to 120 moving over a set distance and then you moved over that same distance twice as fast elevating your hear-rate up to 160 if you would really double the number of calories you burned per unit time.

By the way for anyone reading along and thinking this is a critical point to resolve for weight loss it isn't. This is a collection of geeks getting overly focused on minutia (myself included I don't mean this as an insult).

The energy to move the body faster or slower the same distance would be the same with the assumptions I gave ( in reality it gets bigger faster you go), but the energy derived from the body to produce the energy to move the body would depend on a lot of things and the efficiency of the body at different operating conditions. I'm not sure exactly where the most efficient operating condition would be for the body but that might be enough at slow speeds to matter and be a determining factor. I can see for low speeds the body being more efficient at a higher speed than a lower speed but that will go away I'm sure once you increase speed beyond that. Would be an interesting study.

NorthCascades

Aaron_K123 wrote: »

blambo61 wrote: »

Aaron_K123 wrote: »

blambo61 wrote: »

Aaron_K123 wrote: »

kakaovanilya wrote: »

I am surprised. I thought the faster you walk, the more calories you burn. Good to know

The faster you walk or run the more calories you burn per unit time but not per mile. The faster you move the faster you complete a mile and therefore the less time you are exercising if you only run one mile. I mean who burns more calories? Someone who walks a mile in 30 minutes or someone who sprints it in 5. Well, the person who took 30 minutes because they are measuring their caloric burn over 6 times the amount of time. If you compared their burn over just 5 minutes then yes the person sprinting burn a lot more than the person walking slowly.

Sorry but it doesn't work that way. If there were no up and down motion due to running vs walking and you ran in a vacuum so that there was no wind resistance, walking or running the same distance would use the same amount of energy (assuming the boy doesn't heat up more running). Energy usage is a function of distance traveled and not speed all those other things being equal. In real life, running does have up and down motion, your going faster which produces more drag which increases proportional to velocity squared, and your at a higher power level so you internally will heat up more. Running a mile will absolutely use more calories than walking. The faster you go for the same distance, the more energy you will burn primarily due to the added wind resistance, internal heating, and up and down motion. Remove those things and it would be equal. The walk will NEVER use less energy than the faster run.

I get that if you are talking about a machine that is built to travel a certain distance that difference that the machine that travels that distance faster will be less efficient than the machine that travels it slower due to drag and therefore will expend more energy in doing so. That I agree with. But are you sure that principle applies to a human whose engine is a biochemical one? For a machine working twice as hard will burn more than twice the amount of fuel. For a body though I am not sure that working twice has hard will burn twice the calories. I mean, ones heart rate can only go so high and I don't think the relationship between effort, heartrate and caloires burned is a linear one.

Picture this scenario. I walk a 26 mile route with an elevated heartrate and it takes me 12 hours. After I lie down and sleep for the remaining 12 hours. My clone ran the same route it and it took them 6 hours, they then lie down and sleep the renaming 18 hours. You are saying that their caloric burn above their 24 hour rate if they had not been active at all would be more than twice as much as mine? Doesn't the amount of time I have an elevated heart rate for (12 hours vs 6 hours for my doppelganger) matter at all?

I have a heart that elevates in rate associated with my metabolic rate elevating due to activity to dispose of excess carbon dioxide. The amount of time I am in that elevated state has potentially more effect than how elevated it gets. In otherwords a person with a bpm of 110 working for 2 hours will likely burn more calories than a person with a bpm of 150 working for 1 hour. Does it matter if the first person ran the same distance as the second person to achieve that bpm elevation over a longer period of time?

I'm not sure that I am correct, maybe you are right....but I'm not so convinced it is as cut and dry as a comparison you are making it out to be. I certainly don't think your comment deserved being "woo'd" though you may be correct.

I agree, hardly a woo comment. Figuring out energy expenditure is way harder using heart rate than a point mass moving a certain distance at a certain speed I think. The heart has a baseline requirement the exercise is added to. That would have to be taken into account. Also your example talks about what happens for a period after the exercise. I'm not sure what would happen with all the physiology in that case.

Looking at the body as a simple point mass moving at a certain speed and going a certain distance and not moving up and down and in a vacuum with no wind drag, speed of going a distance doesn't matter. The only thing that matters is the weight of the object and the distance it is moved. If you add in wind resistance, the faster you go, the more energy is required because drag force increased by the square of the velocity (non-linear). If you add in up and down motion of running, then running will take more energy going to same distance as walking it.

Energy = Force x Distance. That is the basic formula for moving a point mass with a constant force. Speed doesn't come into play. Distance = Velocity x time for a constant velocity. If you go twice as fast for half the time as another trip, you go the same distance.

I feel I understood your point, I think its just more complicated that a point mass experiencing drag forces. Not to say you aren't correct, I just feel like I already understood that point and still feel like elevating ones heartrate for a longer period of time can result in a larger loss of calories even if one isn't moving as fast. I mean its pretty clear that at somepoint the linearity of this relationship between speed and calories burnt has to break down. You can't go from 0.5 mph to 1mph to 2mph to 4 mph to 8 mph and double calories burnt each time or the difference between 0.5 and 8 would be 2^4 more calories which would be 16 times more calories. Which means if you burnt 100 calories going 5 miles at 0.5mph you'd burn 1600 calories going 8mph over that distance? Seems unlikely right?

I dunno. The idea you're going with, it places a limit on how fast you can go. If you adjust the numbers a little, that winds up being about how fast you can actually go.

blambo61

Aaron_K123 wrote: »

PAV8888 wrote: »

You guys do realize that there's a compendium of physical activities that has measured actual humans walking and running at varying speeds and how much energy they're expending when they do so.

And that the relative values are comparable in that they're expressed in METs, i.e. as multipliers of a hypothetical one MET expenditure.

Google compendium of physical activities and look up the walking and running tables.

You will notice that the per minute expenditure of calories increases as the speed increases (duh) and that pretty much all walking speeds have a lower per minute expenditure then pretty much all running speeds.

The only exception is extremely fast walking where people's form breaks down and changes when it is compared to extremely slow running.

I don't think anyone here would disagree with the notion that the faster you move the more calories you burn per unit time . The dispute was over if speed factored into amount of calories burned over the same difference regardless of time.

Calories burnt per unit time is the definition of power. The faster you go the higher the power level, but just like a 100W light bulb in use for 10-hrs uses 1kw-hr of energy, a 50W light bulb in use for 20-hrs also uses 1kw-hr of energy. Energy used isn't measured at an instant of time, power is. Energy is the sum of power (integral) over time. For a constant power level. Energy = Power x time elapsed.