Energy to run a mile = energy to walk a mile? True or False?

A little more complicated then all that. Using the calculator on that site one can find the following results for a 75kg person.

1 mile run at 16km/hr costs 121 calories.

6 mins at 16km/hr is 1600m.

1 mile walk at 4km/hr costs 98 calories.

24 mins at 4km/hr is 1600m.

Roughly 10 minutes at 10km/hr close to a mile (a little over actually which accounts for the higher calorie count below).

1 mile run at 10km/hr costs 128 calories.

1 mile walk at 10km/hr costs 136 calories.

Clearly there is a non-linear relationship between calories expended and the method by which one expends them. It seems to me that running has a very flat cost curve meaning ramping up in speed only requires slightly more expended energy. Walking on the slow end is more efficient but the cost curve is quite steep; walking only a little bit faster results in much higher energy expenditure.

Engineer wrote:

Your engineer friend is mostly correct.

Seriously? You read the thread and came to that conclusion? Come on man this myth has been nailed from multiple angles from multiple people.

I'm going to pull my 'I'm a Chartered Physicist' card here. The engineer friend is not correct.

Nothing against engineers. My older brother is one and even though he earns about 3 times more than me I'm not bitter. :)

Are we abundantly sure that if a well trained fat utilizing athlete that is a sub 5 miler goes out at 9:00 jogging pace on say a certain grams of fat molecules that he would cover LESS miles than a 20:00 pace walker on the same amount of fat molecules? You do have elastic recoil gaining you stride length that the walkers can't take advantage of. No doubt walking takes less energy per unit time but does that necessarily mean it can cover the maximum mileage?

fat burning wrote:

Are we abundantly sure that if a well trained fat utilizing athlete that is a sub 5 miler goes out at 9:00 jogging pace on say a certain grams of fat molecules that he would cover LESS miles than a 20:00 pace walker on the same amount of fat molecules? You do have elastic recoil gaining you stride length that the walkers can't take advantage of. No doubt walking takes less energy per unit time but does that necessarily mean it can cover the maximum mileage?

Yes

ventolin^3 wrote:

the "true physics" is

energy = 0.5 * m * v^3 * s

- for a 70kg guy walking a 15 minute mile, enegy expended =

0.5 * 70 * ( 1609.344 / (15*60) ) * 1609.344 = 322060J

- for a 70kg guy running a 4 minute mile, enegy expended =

0.5 * 70 * ( 1609.344 / (4*60) ) * 1609.344 = 16983604J

Appreciate the time you took to do that, but dang Vento, I think you are puffing on your inhaler too much^3.

16983 kj in 4:00?! Are you out of your mind? That's roughly 95 horsepower. If Rupp had that sort of power he could run a mile in approximately 23 seconds.

So hiking 26 miles should require the same energy as running a hilly trail marathon then? Umm, no!

well whether thats true or not for the actual 4 and 15 minutes its going to cost more energy recovering from that 4 minute mile so the 4 minute mile burns more at the end of the day, dont let an engineer tell you anything about exercise science

Recovery from muscle damage is definitely extra. What I want to know is if someone was to give me $100 for every foot I can cover given a finite tank of calories (not concerning any post-energy needs of recovery) and I am standing there on the starting line. By what strategy do I go out? Do I walk at 16 min/miles or 18 or 20 or take one step every few minutes? Is there an optimum answer or is it the answer the slowest pace you can possibily walk but even standing takes energy.

This is the internet you F**kfaces,

What the hell are intelligent and serious responses doing here?

You're all an embarrassment to anonymous message boards everywhere.

In all seriousness though I think some valid points have been raised, I'm not sure what the consensus should be but I will say that I'll run 10 miles anyday....walking 10 miles would be a god damn ordeal.

Running requires leaving the ground and also hitting the ground at a greater force than walking.........

that's why i added correction :

units aren't J, but just undefined units

the energy output is more complicated to measure in J as wiki article on drag shows :

the above power has to be multiplied by 240s ( for a mile run in 4'00 ) to get energy output in J

as you can see, you need accurate metric values for density of air & area to get a J value

however, it doesn't detract from relative energy required to run it in 4'00 or 15'00 : it is

~ 14

Theory vs practical? Me thinks the same person feels more fatigued after running a 4-minute mile than he/she did a 15-min one. Wonder why that is for the same individual covering the same distance at dramatically different paces?

His correctness all depends on how much you want to simplify the problem. Ideally with no air resistance and not worrying about efficiency they would be the same. Accomplishing the same task (moving some mass some distance) would use the same amount of energy. The extra time the walker is out there would make up for the fact that the runner was using energy much quicker.

Think of an envelope licking job and one person does 400/minute and the other 100/minute. If they each lick 1600 envelopes, they do the same work, require the same energy. The first is done in 4 minutes, the second is done in 16 minutes. Now just change envelopes to meters and you have your mile (well 9 meters short).

But in real life the runner has to do extra work against air resistance and creates more heat (energy lost). Energy is work, work is energy. So this extra work is extra energy. This doesn't even include what happens after the mile, the runner would continue to burn extra energy for some time after.

Runners elevate, thus defying gravity. Hence, they expend more energy. Walkers can boost calorie expwnditure by walking hills.

They actually did a study on total energy used on horses running at different speeds.

On higher speed there was higher energy and on the slowest speed there was less used in total - as expected

However, they found an optimum speed where the least total energy used was a trotting speed but not the slowest - a kind of medium trot

Jogging is alaways going to use more enery than walking (unless walking flat out). But on running there will be a medium jooging pace that used the least total energy just like the horses. I assume this is because running at a very slow speed is not biomechanically efficient

Randy Oldman wrote:

Xfit_guy_the_real_1 wrote:

FACT: Running a mile is a waste of time.

You don't get JACKED, you don't get RIPPED. What is the point? So you can say you ran a mile? Seriously?

Your man parts must be really tiny.