Calories burned: walking vs running

Factual Questions
1

Simple question.

Does walking five miles burn the same number of calories (approximately or exactly) as running the same five miles?

Note that I’m not asking which form of exercise is better for you, or the difference in cardio impact, or anything like that. Seems to me it’s more of a physics question, in terms of “work done,” except that it’s a human being doing the work. I just don’t know if there are any other wrinkles to it.

I heard this claim made recently and thought I’d get the SDMB’s expert opinion. I have no opinion on the issue; I don’t know enough about this to consider the plausibility of it being either true or false. Hence, the thread.

2

Theoretically, as you say, the work done would be the same, but one thing I’ve read is that running burns *more in calories because there’s more vertical movement than just walking.

Also, I wonder if there is a measurable increase in expenditure due to increased drag?

*FWIW, the article (in a weekend newspaper supplement) said “up to 20% more,” which seems a little high to me.

3

Running burns more. I’ll leave the calculation to you.

4

That’s a good question. I’ve been told they would work out about the same, since the running is more active but for a shorter time to reach the 5 miles.

5

[QUOTE=Earl Snake-Hips Tucker]
Theoretically, as you say, the work done would be the same, but one thing I’ve read is that running burns *more in calories because there’s more vertical movement than just walking.

Also, I wonder if there is a measurable increase in expenditure due to increased drag?

*FWIW, the article (in a weekend newspaper supplement) said “up to 20% more,” which seems a little high to me.
[/QUOTE]

The work done is equal, but the energy expended to acomplish said work is not. For example, does a car get better fuel economy going 45 or 95?

Yes, the force to to drag is proportional to velocity squared. Measurable, yes, significant? Depends on wind speed, frontal body area, etc.

20% seems about right, based on the numbers in the link above. I didn’t run them, but it seems reasonable.

6

[QUOTE=Pygmy Rugger]
The work done is equal
[/QUOTE]
Why would you say that?

Sure, work is defined as force times displacement (well, dot product), but to claim the work is equal (seemingly) just considers horizontal displacement.

Generally speaking. . .there’s more vertical displacement with each running stride, wouldn’t you agree?

And, yes, the wind resistance would increase the amount of force needed to jog, also, but I bet that factor is much less than the springing/landing nature of running as compared to the falling/planting nature of walking.

7

http://www.straightdope.com/columns/050121.html

8

Personal experience tells me that I feel like I’m still burning calories a lot longer post-exercise if I went running compared to walking… that is my body stays warm/metabolism seems higher, which I would assume means burned calories.

9

[QUOTE=Trunk]
Why would you say that?

Sure, work is defined as force times displacement (well, dot product), but to claim the work is equal (seemingly) just considers horizontal displacement.

Generally speaking. . .there’s more vertical displacement with each running stride, wouldn’t you agree?

And, yes, the wind resistance would increase the amount of force needed to jog, also, but I bet that factor is much less than the springing/landing nature of running as compared to the falling/planting nature of walking.
[/QUOTE]

[QUOTE=Pygmy Rugger]

The work done is equal,** but the energy expended to acomplish said work is not.** For example, does a car get better fuel economy going 45 or 95?

Yes, the force to to drag is proportional to velocity squared. Measurable, yes, significant? Depends on wind speed, frontal body area, etc.

[/QUOTE]

Sure, there’s vertical work done with each leg thrust, but you get it back on the way down. Physical work doesn’t always relate to how hard it is to do something. For example, the classic calculus problem of pulling a bucket connected to a chain out of a well. The math says that there is less work performed as you pull the bucket up, because the weight of the chain is “decreasing”, because there’s less of it. But if you were pulling the bucket up, it would get harder on your arms and back with each stroke, due to muscle fatigue. Hence my statement, “the energy expended to accomplish said work is not (equal).”

I also agree that the springing force of landing and taking off while running is more significant to your muscles than the increased wind resistance. The OP asked if change in wind resistance was measurable. It is. I questioned its significance.

What I’m saying is, yes, your body works harder. But, using the physics definition of work, it is the same. Same word, two different definitions.

10

[QUOTE=Pygmy Rugger]
Running burns more. I’ll leave the calculation to you.

http://www.nutristrategy.com/activitylist3.htm
[/QUOTE]

Running burns more calories per hour because you cover more distance running for an hour than you do walking for an hour.

When I’ve hunted this down before, I’ve found sources that agree with this article (all due respect to Himself) that says both running and walking expend roughly 100 calories per mile, all fancy calculations aside.

11

[QUOTE=Quiddity Glomfuster]
Running burns more calories per hour because you cover more distance running for an hour than you do walking for an hour.

When I’ve hunted this down before, I’ve found sources that agree with this article (all due respect to Himself) that says both running and walking expend roughly 100 calories per mile, all fancy calculations aside.
[/QUOTE]

According to the website I cited, for a person weighing 155 lbs, running at 10 mph for one hour (10 miles) would burn 1126 calories. Walking at 2 mph would burn 176. If you do this for 5 hours, you would go 10 miles and burn 880 calories. 1126/880 = 1.28, or a difference of about 30 percent.

Yes, you’re right, they both burn roughly 100 cal/hr. But walking (using the numbers in my above calculation) uses 88, while running uses 113 per hour. They are both roughly 100, but they are not equal.

12

[QUOTE=Pygmy Rugger]
The work done is equal, but the energy expended to acomplish said work is not. For example, does a car get better fuel economy going 45 or 95?
[/QUOTE]
The work done in the two scenarios is the car example are *not * equal. Work is force through the distance, and a car at 95 exerts a greater force through the same distance, primarily due to air resistance.

However, the whole work-is-equal notion is a bit of a red herring, because work doesn’t tell you much about how much energy was consumed. The same car will use different amounts of energy at the same distance and speed if it’s in two different gears in the two trials. Energy consumption is more of an engineering issue regarding efficiency.

Others are discussing the efficiencies of running vs. walking so I won’t try to get into that.

13

[QUOTE=CookingWithGas]
The work done in the two scenarios is the car example are *not * equal. Work is force through the distance, and a car at 95 exerts a greater force through the same distance, primarily due to air resistance.

However, the whole work-is-equal notion is a bit of a red herring, because work doesn’t tell you much about how much energy was consumed. The same car will use different amounts of energy at the same distance and speed if it’s in two different gears in the two trials. Energy consumption is more of an engineering issue regarding efficiency.

[/QUOTE]

Exactly. This is what I was trying to say. You worded it much better than I have.

14

[QUOTE=Pygmy Rugger]

Yes, you’re right, they both burn roughly 100 cal/hr. But walking (using the numbers in my above calculation) uses 88, while running uses 113 per hour.
[/QUOTE]

No, per mile.

So it would take you 140 miles to take off one pound more running than you would if you were walking :smiley: Thanks but I’ll save my joints :stuck_out_tongue:

15

You don’t get the work out of the downfall. Same as a ball doesn’t bounce as high on subsequent bounces. However, you do have to elevate to the same height with each stride or you will trip and fall. Increased wind resistance is one component of going faster, whether driving or running. An engine has efficiency curves, and so does the body. The body is more efficient maintaining a walking speed than a running speed, so fuel (calories) are consumed (burned) at a faster rate. This question is so old and easily answered from numerous other websites, I’m curious why it still lingers.
A better question would be, which burns more calories, running on a treadmill or running on the sidewalk? The answer is the sidewalk because you have to push off the ground in order to move forward. The treadmill moves for you, so all you’re doing is lifting your legs (i.e running in place)

16

edit - you don’t all the work out of the downfall

17

[QUOTE=TYOV]
A better question would be, which burns more calories, running on a treadmill. . . .
[/QUOTE]
Just. . .don’t. . .go. . .there :smiley:

18

According to an activity calorie calculator website I use frequently:

A 170 pound person walking 2.5 mph for two hours burns 464 calories.
A 170 pound person running 5.0 mph for one hour burns 618 calories.

19

The intensity of your exercise makes a big difference in how your body allocates resources and adapts to the activity. There are different pathways for metabolism and they have different rates of efficiency. The physics of it has some bearing, but it’s not as relevant as the biological side of things, I think. Intensity also has an effect on your overall and cardiovascular fitness, which in turn has an effect on your non-exercising metabolic rate. In fact, basal metabolic rate accounts for the majority, around 70% of the calories used by your body every day, and different forms of exercise have very different effects on that.

When you see tables that have X calories burned over Y time, those are averages of the energy expended in that time and place by the people they used in whatever study they did to compile the information. It’s good for general information purposes but can’t be taken as a true answer for any particular individual. In addition, it doesn’t measure effects for people of varying fitness levels, and it doesn’t take into account any effects on metabolism outside of the actual time of direct measurement.

Someone who runs 3 miles a day at a good rate of speed will almost certainly be more fit than someone who takes ambling walks 3 miles a day. And I’d be willing to bet that the runner will have lower body fat, assuming all other factors are balanced.

20

[QUOTE=GingerOfTheNorth]
According to an activity calorie calculator website I use frequently:

A 170 pound person walking 2.5 mph for two hours burns 464 calories.
A 170 pound person running 5.0 mph for one hour burns 618 calories.
[/QUOTE]
That amthes what the treadmill says at the gym. (I trian indoors in the winter because I’m a wuss who hates the cold). You plug in your weight, and it calculates your workout based on the incline that you set the treadmill, your speed, and the time you spend on it.

Yes, if I run an hour, I definitely use up more calories than if I walk an hour. I also cover a lot more distance. But that’s the PER/HOUR difference. If I walk the same distance that I run, I’d be on the treadmill all afternoon.