Too much cardio... (Read 3039 times)

Interesting, though non-scientific article: http://www.nytimes.com/2007/10/11/fashion/11Best.html?_r=1 What really interested me about it is the claim that Paula Radcliffe was able to increase her pace by 40-60 seconds per mile without a change in oxygen intake.

I sort of viewed the calories burned like a basic physics problem with the calories burned per mile being essentially constant regardless of how fast, slow, or efficient you ran. It obviously is higher for people with higher weight (more overall energy necessary to move more weight over a given distance) and lower for lighter runners.

physics geek on/ FWIW, basic physics says that it takes no energy to move any mass at constant velocity over a given distance. Once in motion a body in motion will continue at that velocity, regardless of mass, without the addition of any force. Energy (work) is a function of force and distance, but the standard force-body diagrams over-simplify the energy it takes to run because once the runner has reached a constant velocity, the energy that is used in running is spent swinging the legs and arms, pumping the blood, etc. In other words, what takes "work" is not so much the application of force by the leg, but making the legs into a sort of wheel so that constant velocity is maintained with the minimum of force applied. So, maybe it is true the calories burned is a function of distance, but I think that this was discovered by empirical methods rather than through analysis of the physics involved.

Energy (work) is a function of force and distance, but the standard force-body diagrams over-simplify the energy it takes to run because once the runner has reached a constant velocity, the energy that is used in running is spent swinging the legs and arms, pumping the blood, etc. In other words, what takes "work" is not so much the application of force by the leg, but making the legs into a sort of wheel so that constant velocity is maintained with the minimum of force applied.

This.

This.

must be followed by this:

So, maybe it is true the calories burned is a function of distance, but I think that this was discovered by empirical methods rather than through analysis of the physics involved.

Show me the science.

As soon as I get a draft on ontology.

Did the "science" really look at the whole range of running velocities? Did the science select for the difference between a well-trained runner who has mastered a skill and your standard joe shmoe from the street? Did it look at the differences between a runner who has trained specifically for a certain pace and the runner's caloric needs at different paces?

I believe so.

Regarding the Ryun/Shorter comparison it doesn't seem all that surprising that a world class miler had a higher VO2max than a world class marathoner. I mean despite the fact that there's a poor correlation between VO2max and race times, this seems to be almost exactly what you'd expect.

Sure. What does that have to do with calorie expenditure?

What does that have to do with calorie expenditure?

Right. I was effectively just saying "Duh" but using more words.

That is a restatement; you have added nothing new here. If by "fuel" you mean calories, then this is an assertion that has not stood up to science. That more or less oxygen enters the lungs has nothing to do with caloric expenditure.

So you're saying that calorimetry doesn't work? If so, you're at odds with about 99% of exercise scientists. O2 consumption is really the only way anyone measures energy expenditure.