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#1




calories question
If I walk 4 miles in an hour one day and then 4 miles in 2 hours another
day, is the number of calories burned still the same? My *thought* is that it is, but I thought I would pose the question for those in the know. Thanks, RJ 
#2




calories question
In article .net,
Rick Johnston wrote: If I walk 4 miles in an hour one day and then 4 miles in 2 hours another day, is the number of calories burned still the same? Yes. You moved the same amount of mass (your body) over the same distance.  Denise denise dot howard at comcast dot net ACE and AFAA certified fitness instructor AFAA step and kickboxing certified 
#4




calories question
Denise Howard wrote:
Rick Johnston wrote: If I walk 4 miles in an hour one day and then 4 miles in 2 hours another day, is the number of calories burned still the same? Yes. You moved the same amount of mass (your body) over the same distance. So do you disagree with the "Compendium of Physical Activity" [1]? Based to the Compendium, a 225lb person burns 123 Cal/mile walking 2.5 MPH and 163 Cal/mile at 5 MPH. Same mass; same distance; 1/3 more Calories at twice the speed. And doesn't that make some sense, based on experience? It takes a lot more effort to walk 5 MPH than 2.5 MPH. I honestly do not know the credibility of the compendium. It seems to be cited and relied on widely. However, there seems to be anomalies in the data. For example, a 225lb person burns 112 Cal/mile and 111 Cal/mile walking 3 MPH and 3.5 MPH respectively  less than walking 2.5 MPH. And the same person burns 128 Cal/mile walking 2 MPH and 4 MPH  which seems to support Denise's response. (As always, the compendium results must be based on the average of a some sample data  I hope. YMMV, especially for more or less muscular people.)  [1] http://prevention.sph.sc.edu/Tools/C...m_tracking.pdf, updated in 2000. Originally published by B.E. Ainsworth et al, "Compendium of Physical Activities: Classification of Energy Costs of Human Physical Activities", Medicine and Science in Sports and Exercise, Vol. 25, No.1, 1993. 
#5




calories question
In article , Joe User
wrote: Denise Howard wrote: Rick Johnston wrote: If I walk 4 miles in an hour one day and then 4 miles in 2 hours another day, is the number of calories burned still the same? Yes. You moved the same amount of mass (your body) over the same distance. So do you disagree with the "Compendium of Physical Activity" [1]? Based to the Compendium, a 225lb person burns 123 Cal/mile walking 2.5 MPH and 163 Cal/mile at 5 MPH. Same mass; same distance; 1/3 more Calories at twice the speed. And doesn't that make some sense, based on experience? It takes a lot more effort to walk 5 MPH than 2.5 MPH. I honestly do not know the credibility of the compendium. It seems to be cited and relied on widely. However, there seems to be anomalies in the data. For example, a 225lb person burns 112 Cal/mile and 111 Cal/mile walking 3 MPH and 3.5 MPH respectively  less than walking 2.5 MPH. And the same person burns 128 Cal/mile walking 2 MPH and 4 MPH  which seems to support Denise's response. (As always, the compendium results must be based on the average of a some sample data  I hope. YMMV, especially for more or less muscular people.) Well, I think you answered your own question, there...the original poster did ask about the difference between 2 mph and 4 mph. :) It's odd that this compendium would list 3 mph as burning more calories (albeit just one) than 3.5 mph. It is known that at some speed which differs a bit from person to person but is usually around 5.5 mph, it's more mechanically difficult to walk than to run, so running at that speed burns calories at a lower rate than walking at that same speed.  Denise denise dot howard at comcast dot net ACE and AFAA certified fitness instructor AFAA step and kickboxing certified 
#6




calories question
Denise Howard wrote:
Joe User wrote: You moved the same amount of mass (your body) over the same distance. So do you disagree with the "Compendium of Physical Activity" [1]? Based to the Compendium, a 225lb person burns 123 Cal/mile walking 2.5 MPH and 163 Cal/mile at 5 MPH. Same mass; same distance; 1/3 more Calories at twice the speed. .... [But] the same person burns 128 Cal/mile walking 2 MPH and 4 MPH  which seems to support Denise's response. .... Well, I think you answered your own question, there...the original poster did ask about the difference between 2 mph and 4 mph. :) My point was: you answered with a generality of physics. Even if the answer (constant caloric expenditure per mile) is correct, I question whether it is because of the physics. The body is not a passive mass. Besides, I question the concept that caloric expenditure is constant for the same distance and the same person. If you ever walked 2 MPH, 3 MPH, and 4 MPH, surely you noticed that those speeds require different amounts of effort. Are you suggesting that this does not result in caloric expenditure? Granted: I would not expect the caloric difference to be great because walking is mostly a pendulum action. Forgive me for splitting hairs. And believe me: I can be convinced that I am wrong. But if I am wrong, I would like a more persuasive or more complete explanation. It is known that at some speed which differs a bit from person to person but is usually around 5.5 mph, it's more mechanically difficult to walk than to run Well, the Compendium data shows a 14% increase in caloric expenditure per mile for every 5 MPH increase between 3.5 and 5 MPH  not a sudden surge at some "knee" in the curve (no pun intended). Granted: the Compendium data is anomalous below 3 MPH. I have not read the study to see if there is explanation. I wonder if there could be a kinesiological explanation. For example, even if the effort seems easier, I wonder if we involve slightly more (small) muscles when walking at slower speeds, perhaps because of some mechanical differences (posture). Intuitively, I would think not. Nevertheless, although you make an interesting point about walking v. running, it seems offtopic. A question relevant to walking mechanics might be: as we increase walking speed  notably from a loping speed of 2 MPH to a brisk speed of 4 MPH  does the mechanical "difficulty" increase in some smooth progression (linear, geometric, exponential, etc)? Even if so, does the caloric expenditure track the mechanic "difficulty" curve? And in any case, why or why not? Perhaps for some physiological or kinesiological reason. I think the Compendium data suggests a monotonic increase in caloric expenditure related to walking speed. That also seems to be common sense (to me). Obviously you disagree; so do several others. So I might be wrong. But a more complete explanation would be helpful to me  perhaps a kinesiological or physicological one. 
#7




calories question
I've posted on this many times. Denise has not been taking notes,
apparently. The compendium is correct, and supports a very interesting mathematical analysis of walking/running using conic sectionsI have this article buried somewhere. Bottom line is the most efficient form of bipedal locomotion (cals/mile) is walking at the socalled "selfselected step". Walking faster (OR slower!!) burns more calories per mile, faster increasing exponentially. There are at least 4 "gaits", each having its own characteristic "burn profile", if you will. None, however, varies their cals/mile with speed the way walking does, precisely because of the pendulum effect of walking, a "forced pendulum" to be more specific, where energy varies as the square of the amplitude. So fast largestrided walking burns exponentially more calories as the speed increases. Shifting from cal/mile to cal per minute, walking also burns more cals/*min* than running, at all speeds above 4 mph, until walking simply cannot match the absolute speed of running, and then the cal burn of running overtakes that of walking. This is because at about 4 mph (depending depending) the "selfselected step" is no longer a walk, but a jog, ie a more efficient gait. All animals naturally "break into" the more efficient gait, as speeds increase. In contrast to walking, running has a fairly constant cals/mile, ie, independent of speed.  Mr. P.V.'d formerly Droll Troll "Joe User" wrote in message om... Denise Howard wrote: Joe User wrote: You moved the same amount of mass (your body) over the same distance. So do you disagree with the "Compendium of Physical Activity" [1]? Based to the Compendium, a 225lb person burns 123 Cal/mile walking 2.5 MPH and 163 Cal/mile at 5 MPH. Same mass; same distance; 1/3 more Calories at twice the speed. .... [But] the same person burns 128 Cal/mile walking 2 MPH and 4 MPH  which seems to support Denise's response. .... Well, I think you answered your own question, there...the original poster did ask about the difference between 2 mph and 4 mph. :) My point was: you answered with a generality of physics. Even if the answer (constant caloric expenditure per mile) is correct, I question whether it is because of the physics. The body is not a passive mass. Besides, I question the concept that caloric expenditure is constant for the same distance and the same person. If you ever walked 2 MPH, 3 MPH, and 4 MPH, surely you noticed that those speeds require different amounts of effort. Are you suggesting that this does not result in caloric expenditure? Granted: I would not expect the caloric difference to be great because walking is mostly a pendulum action. Forgive me for splitting hairs. And believe me: I can be convinced that I am wrong. But if I am wrong, I would like a more persuasive or more complete explanation. It is known that at some speed which differs a bit from person to person but is usually around 5.5 mph, it's more mechanically difficult to walk than to run Well, the Compendium data shows a 14% increase in caloric expenditure per mile for every 5 MPH increase between 3.5 and 5 MPH  not a sudden surge at some "knee" in the curve (no pun intended). Granted: the Compendium data is anomalous below 3 MPH. I have not read the study to see if there is explanation. I wonder if there could be a kinesiological explanation. For example, even if the effort seems easier, I wonder if we involve slightly more (small) muscles when walking at slower speeds, perhaps because of some mechanical differences (posture). Intuitively, I would think not. Nevertheless, although you make an interesting point about walking v. running, it seems offtopic. A question relevant to walking mechanics might be: as we increase walking speed  notably from a loping speed of 2 MPH to a brisk speed of 4 MPH  does the mechanical "difficulty" increase in some smooth progression (linear, geometric, exponential, etc)? Even if so, does the caloric expenditure track the mechanic "difficulty" curve? And in any case, why or why not? Perhaps for some physiological or kinesiological reason. I think the Compendium data suggests a monotonic increase in caloric expenditure related to walking speed. That also seems to be common sense (to me). Obviously you disagree; so do several others. So I might be wrong. But a more complete explanation would be helpful to me  perhaps a kinesiological or physicological one. 
#8




calories question
I wrote:
Besides, I question the concept that caloric expenditure is constant for the same distance and the same person. If you ever walked 2 MPH, 3 MPH, and 4 MPH, surely you noticed that those speeds require different amounts of effort. Are you suggesting that this does not result in caloric expenditure? First, of course I meant "does not result in __more__ caloric expenditure". Second, I think we all agree that it does result in more caloric expenditure __per_hour__. I should have asked: Are you (Denise) suggesting that the increased caloric expenditure is proportional to the speed increase? I must admit that I would expect a proportional increase, as we see in the Compendium for 2 and 4 MPH. And if that were generally the case, I agree that the caloric expenditure per mile would be constant. But the point is: the increased caloric expenditure is __not__ proportional to the speed increase in general, according to the Compendium. 2 and 4 MPH are the exception, not the rule. "Proctologically Violated©®" wrote: So fast largestrided walking burns exponentially more calories as the speed increases. That is what I saw in the data, too. But since I am rusty with exponential curve fitting and because the data did not closely fit the exponential curve that Excel produces, I discovered that the data also fits two straight lines with different slopes, one from 2 to 3.5 MPH, and the other from 3.5 to 5 MPH. The linear fits are even better when I apply a theory of roundoff error. Since I do not have the original data, the reported 2 MPH value of 2.5 MET, for example, could be any value between 2.450 and 2.549 MET. Walking faster (OR slower!!) burns more calories per mile, faster increasing exponentially. While calories/hour increases exponentially, calories/mile changes linearly. And oddly, calories/mile __decreases__ between 2 and 3.5 MPH, but increases between 3.5 and 5 MPH. In any case, these slopes are very different from a constant amount caloric expenditure. I've posted on this many times. Denise has not been taking notes, apparently. I will try to find those earlier discussions. I would be very interested in Denise's take on all this, as well as other qualified individuals. The compendium is correct, and supports a very interesting mathematical analysis of walking/running using conic sections I have this article buried somewhere. I still have not found the article. I just have the tables. In any case, I would be very interested in others' knowledge of the acceptance of the Compendium, in both the academic and the fitness communities. 
#9




calories question
 "Joe User" wrote in message om... I wrote: Besides, I question the concept that caloric expenditure is constant for the same distance and the same person. If you ever walked 2 MPH, 3 MPH, and 4 MPH, surely you noticed that those speeds require different amounts of effort. Are you suggesting that this does not result in caloric expenditure? First, of course I meant "does not result in __more__ caloric expenditure". Second, I think we all agree that it does result in more caloric expenditure __per_hour__. I should have asked: Are you (Denise) suggesting that the increased caloric expenditure is proportional to the speed increase? I must admit that I would expect a proportional increase, as we see in the Compendium for 2 and 4 MPH. And if that were generally the case, I agree that the caloric expenditure per mile would be constant. But the point is: the increased caloric expenditure is __not__ proportional to the speed increase in general, according to the Compendium. 2 and 4 MPH are the exception, not the rule. "Proctologically Violated©®" wrote: So fast largestrided walking burns exponentially more calories as the speed increases. That is what I saw in the data, too. But since I am rusty with exponential curve fitting and because the data did not closely fit the exponential curve that Excel produces, I discovered that the data also fits two straight lines with different slopes, one from 2 to 3.5 MPH, and the other from 3.5 to 5 MPH. The linear fits are even better when I apply a theory of roundoff error. Since I do not have the original data, the reported 2 MPH value of 2.5 MET, for example, could be any value between 2.450 and 2.549 MET. Walking faster (OR slower!!) burns more calories per mile, faster increasing exponentially. While calories/hour increases exponentially, calories/mile changes linearly. And oddly, calories/mile __decreases__ between 2 and 3.5 MPH, but increases between 3.5 and 5 MPH. Actually, not odd at all. The reason it incrases from 2 to 3.5 is that the contribution of BMR to the total increases proportionally with alloted time. If the test were done at .5 or 1 mph, you'd see the effect even more. Imagine the caloric expenditure per mile if you took all day to walk a mile! Uh, 2,500 cal/mile?? Thus, BMR can blur or even swamp the caloric expenditure of the activity itself. Try this: Find the VO2 for, say, sitting or standing (not BMR, but perhaps more relevant), subtract that from the VO2's for the various activities at various speeds, and compare *those* numbers. You might get better fits/results in your analyses. This subtraction of BMR or rest VO2 from the total VO2 gives a much better comparison of the mechanical output of activities or speeds.  Mr. P.V.'d formerly Droll Troll In any case, these slopes are very different from a constant amount caloric expenditure. Because two different processes are involved in the increase in cals/mile, you would expect two different slopes. I've posted on this many times. Denise has not been taking notes, apparently. I will try to find those earlier discussions. I would be very interested in Denise's take on all this, as well as other qualified individuals. The compendium is correct, and supports a very interesting mathematical analysis of walking/running using conic sections I have this article buried somewhere. I still have not found the article. I just have the tables. In any case, I would be very interested in others' knowledge of the acceptance of the Compendium, in both the academic and the fitness communities. 
#10




calories question
For curve fitting try TableCurve 2D at http://www.systat.com/products/TableCurve2D/
Joel (Joe User) wrote in message . com... I wrote: Besides, I question the concept that caloric expenditure is constant for the same distance and the same person. If you ever walked 2 MPH, 3 MPH, and 4 MPH, surely you noticed that those speeds require different amounts of effort. Are you suggesting that this does not result in caloric expenditure? First, of course I meant "does not result in __more__ caloric expenditure". Second, I think we all agree that it does result in more caloric expenditure __per_hour__. I should have asked: Are you (Denise) suggesting that the increased caloric expenditure is proportional to the speed increase? I must admit that I would expect a proportional increase, as we see in the Compendium for 2 and 4 MPH. And if that were generally the case, I agree that the caloric expenditure per mile would be constant. But the point is: the increased caloric expenditure is __not__ proportional to the speed increase in general, according to the Compendium. 2 and 4 MPH are the exception, not the rule. "Proctologically Violated©®" wrote: So fast largestrided walking burns exponentially more calories as the speed increases. That is what I saw in the data, too. But since I am rusty with exponential curve fitting and because the data did not closely fit the exponential curve that Excel produces, I discovered that the data also fits two straight lines with different slopes, one from 2 to 3.5 MPH, and the other from 3.5 to 5 MPH. The linear fits are even better when I apply a theory of roundoff error. Since I do not have the original data, the reported 2 MPH value of 2.5 MET, for example, could be any value between 2.450 and 2.549 MET. Walking faster (OR slower!!) burns more calories per mile, faster increasing exponentially. While calories/hour increases exponentially, calories/mile changes linearly. And oddly, calories/mile __decreases__ between 2 and 3.5 MPH, but increases between 3.5 and 5 MPH. In any case, these slopes are very different from a constant amount caloric expenditure. I've posted on this many times. Denise has not been taking notes, apparently. I will try to find those earlier discussions. I would be very interested in Denise's take on all this, as well as other qualified individuals. The compendium is correct, and supports a very interesting mathematical analysis of walking/running using conic sections I have this article buried somewhere. I still have not found the article. I just have the tables. In any case, I would be very interested in others' knowledge of the acceptance of the Compendium, in both the academic and the fitness communities. 
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