Caloric expenditure

[Mudge]

Being discussed on another board. The claim is that running a mile, or walking a mile - both consumes the exact same number of calories.

Everything I can think of, goes directly against this. A car racing in a mile vs 'driving' a mile has a different BSFC. 10mbit vs 100mbit vs 1gbit all require different quality of wire, all at increased cost.

Nothing in life is free, how could the human body be so perfect to scale upwards like such at zero increased cost? I dont believe it.

For every calorie we burn, we consume a fixed amount of oxygen. By measuring oxygen consumption then we can calculate the caloric burn rate.

This is the only thing interesting I can find so far.

 

[Pepper]

I have always heard that by distance, walking vs running has only a minor difference in calories - 15% or so.

But that is only dealing with the calories burned during the exercise.

 

[Arnold]

Originally posted by Mudge
Being discussed on another board. The claim is that running a mile, or walking a mile - both consumes the exact same number of calories.

I do not even see how this is a debate!

It's completely FALSE.

 

[Mudge]

Another
http://www.kangacrossing.com/Us2.htm

e=mc^2
F=MA
A is an exponential factor

Ignoring wind frictions, which are 3rd power exponential

Prince, I likewise dont understand it, it goes against everything known to man that I can think of, nothing is free, always increased cost with increased work - it would be saying we are the perfect machine.

 

[DaDaMan1010]

i agree with you prince

 

[Mudge]

Running, vs walking, are also very different. You "jump" from step to step when you run, where with walking you are going from one foot to another. It even brings the upper body more into play.

 

[Pepper]

Found this

Running a mile burns the same calories as walking a mile: This was an interesting topic, because many experts I consulted and articles I read claimed that running and walking for a mile burn the same amount of calories. The reasoning is that walking a mile takes more time than jogging a mile. Therefore, you will burn the equivalent calories, but it just takes longer. It makes sense, but it isn't completely accurate.

"You will burn up to 20 percent more calories per mile by running at 6 to 7 miles per hour versus walking at a pace of 3 to 4 miles per hour," said William Haskell, Ph.D., professor of medicine at the Stanford University Center for Research in Disease Prevention. "The primary reason for the additional calories burned is the vertical movement required by the body to propel both feet off the ground while running."

 

[Mudge]

Which just disagreed with his own statement. But, he is saying if we lived in a vacuum with no increased cost of friction and so on that minus the movement difference it would somehow cost the same, which I still have a hard time swallowing.

 

[Pepper]

Originally posted by Mudge
Which just disagreed with his own statement.

Not sure what you mean by that. The title of the article was Workout/Diet Myths. So the statement was a statement of the myth followed by the author's debunking of the myth.

 

[Mudge]

Never mind me I read it again.

Primary reason, which must mean not the sole reason, which is exactly what I'm looking for.

 

[Robboe]

I've read abpout this years ago and it is very much true. It threw me a while also.

The concept is based purely around the calorie expenditure during the activity, since more strenuous movement has more profound repercussions on metabolic and hormonal activity which will effect the calorie expenditure post-activity.

 

[Trump]

Simple physics.

Same work is complete over a distance, walking vs. running.

However, the difference is the POWER exertion over that distance.

 

[gr81]

this can't be true. By running you are working harder, therefore you will reach you target heartrate quicker and therefore burn more calories being in this THR. Walking a mile I wouldn't even come close to reaching that heart rate, no way this is true. There is a difference between high intensity and low intensity cardio, otherwise wouldn't walking be enough.

 

[OceanDude]

Originally posted by Mudge
Being discussed on another board. The claim is that running a mile, or walking a mile - both consumes the exact same number of calories.

I am an engineer and can???t even begin to accept this as possible. It???s the classical ???area under the curve??? for energy expenditure versus time (integral calculus) being conjectured as being identical for two completely different rate expenditure profiles ??? using what is suppose to be the same system/engine (this I believe is the fallacy in the assumption). The assertion asks us to accept that ???the system??? is equally efficient independent of speed. This has been proven to not be the case for sterling, diesel and auto thermodynamic cycles when applied to automotive applications ??? if those were to apply.

I like Mudge???s car analogy and energy equations. Just as in a car???s engine we are constrained by the fundamental systematic torque and HP curves (transfer functions) of the engine (which are not linear due to fundamental chemical properties of the fuel and fixed mechanical configuration of the engine). Also, wind resistance being a cubic in velocity is EXTREMELY relevant at those speeds (over 150 mph) and must be somewhat relevant even at walking versus running speeds (you just can???t ignore any cubic factor). But unlike the car that uses rotational motion of the wheels as a fundamental and constant form of propulsion we humans change and adapt our fundamental form of motion significantly as we transition from walking to running (gliding verses jumping/leaping) ??? and even utilize a different fuel mix. The energy expended in the vertical motion is largely non-recovered and we must assert additional energy for balance and stability. But the biggest factor in my eyes is that we are fundamentally naturally/evolutionarily ???pre-configured??? for low speed walking for the majority of our daily ???duty cycle???. Except for the totally weird among us, we would all naturally prefer to walk rather than run to ???most??? places. This is consistent with the observation that we experience relative physiological ???discomfort??? in running (relative to walking). I conjecture that this is natural built-in mechanism to compel/dissuade us to NOT burn our limited premium fuel forms (glycogen) irresponsibly and only use the non-preferred running form of mobility when we absolutely need to (or the current discomfort is going to be replaced by something more pleasurable such as that cute barbarian chick we see walking naked along the beach). And, let???s not forget that at low walking speed you are dealing with fundamentally different fuel make-up than you are at running speed (higher ratios of lipids as fuel at walking verses higher ratios of glycogen as fuel at running); two completely different energy metabolic pathways that???s just so happen to use the same limbs for mobility (though I swear I have seen guys also flapping their arms with dumbbells as if trying to fly). In engineering any time a system is utilized outside it's primary and preferred designed operating mode we can expect less efficient energy utilization at the extremes (both low and high). If this rationale applies to the human body (and I think it does), at the high end, we are likely to be able to discover fundamental chemical inefficiencies such as incomplete oxidizing and ???burning??? of glycogen fuel, dealing with higher rates of cooling more fiber [variable horsepower], dealing with faster rates of lactic acid build up etc.). Now back to the (stock) car analogy. Where do you get better fuel economy (let???s not get into stop and go scenarios but assume driving constant on the highway) at low speed or at high speed? But now I am not so sure that the car analogy even applies since it is a fixed fuel engine with a single mode of mobility using a non-adaptive and fixed thermodynamic cycle for whatever kind of engine it is using ( 4-stroke, 2-stroke, wankel, diesel, turbine etc.) and fuel (gasoline, diesel, kerosene etc.). The human body seems to have a hybrid engine that can use mixed or alternate fuels and has a modified mode of propulsion form dependent on speed.

So, from my perspective, in human physiology we are really dealing with a hybrid kind of ???engine??? that dependent on speed and pre-existing fuel levels burns two fundamentally different forms of fuel. The walking ???pleasant??? mode of motion is preferred and is geared for long term survival (slow efficient motion) and the other running form is geared for short ???term survival (fast relatively fuel-inefficient motion used to run like hell from that attacking killer jelly donut that the sneaky dinosaur is rolling our way as bait). Now unless it???s the wildest form of serendipity that the body uses both fuel systems with identical efficiency ??? there is no way to expect identical caloric expenditures.

 

[Mudge]

Originally posted by gr81
this can't be true. By running you are working harder, therefore you will reach you target heartrate quicker and therefore burn more calories being in this THR.

It has nothing to do with target heart rate nor is any heart rate defined. The theory of thiers was that the work was linear, so working twice as hard will burn identical calories if working half as hard as example #1 but over twice the time.

Since the movement is indeed different, and we have friction in the real world, it is definitely not true and they were dreaming to think so.

 

[Robboe]

I wish i wasn't so tied up these days or else i may put more input into this, but it is true.

Originally posted by The_Chicken_Daddy
The concept is based purely around the calorie expenditure during the activity, since more strenuous movement has more profound repercussions on metabolic and hormonal activity which will effect the calorie expenditure post-activity.

 

[Snake_Eyes]

This isn't a closed system.

Metabolic work to generate force works on a balance of substrates. The difference in the calories burned is largely the effect of the ratio of the substrates-- triglycerides and glycogen-- being used to fuel the activity.

So as mentioned, its more a function of the curve of power....work wrt time.

A longer, slower action uses triglyceride metabolism. Not particularly heavy on the calorie usage, but kept up for a "long" period of time. Running is working via glycolytic metabolism and is a lot more intensive in terms of work used, but its active over a "short" time frame.

So its a balancing act. Rate of calorie usage vs. duration of usage.

And what Chigs said.