[net.med] exercise?

ark@alice.UucP (Andrew Koenig) (03/06/86)

I asked this question some time ago and never got a clear answer,
so I'm trying again.

Is there an easy way to figure out how many calories are burned
by a given amount of exercise, given that I can actually measure
energy output?

For example, suppose someone puts out 150 watts for 15 minutes.
How many calories of intake are necessary to produce that much
output?

jin@hropus.UUCP (Jear Bear) (03/06/86)

To answer you literally: No input is necessary to output that amount of
energy, the body will usually have enough stored energy.  To calculate
kilocalories (the nutritionist's type) multiply watt-hours by 0.8605

So your example (if my memory serves me correctly) is .8605*(150.*15./60.)
or 32.27 (rounded) kcals.
-- 
			Jerry Natowitz
			ihnp4!houxm!hropus!jin
			The Master Baker

ahs@burl.UUCP (Spinks Albert H. ) (03/07/86)

Think about your problem with the simple engineering equations

output =  input - losses

OR

output = (efficiency)(input)

You say you can measure your output in some way; so all you need is
the value of losses or the efficiency of the body (which I would guess
is low).  I don't know what our efficiency is but someone
on the net should know.

Good luck.

-- 




				     Albert H. Spinks

hollombe@ttidcc.UUCP (The Polymath) (03/10/86)

In article <5079@alice.uUCp> ark@alice.UucP (Andrew Koenig) writes:
>Is there an easy way to figure out how many calories are burned
>by a given amount of exercise, given that I can actually measure
>energy output?
>
>For example, suppose someone puts out 150 watts for 15 minutes.
>How many calories of intake are necessary to produce that much
>output?

Multiply watts by 9.481 * 10^-4 to obtain BTU/second.
Multiply BTU by 2.520 * 10^-1 to obtain kg calories.

Source: Pratt & Whitney Aeronautical Vest-Pocket Handbook

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werner@aecom.UUCP (Craig Werner) (03/11/86)

> Is there an easy way to figure out how many calories are burned
> by a given amount of exercise, given that I can actually measure
> energy output?

	Is there an easy way. No.  The only completely accurate way is to
build yourself a calorimeter and measure the change in ambient temperature.
These are very expensive, and very tricky.  If you were the person who
specifically asked the dependence on caloric expenditure of different
manners fo stairclimbing, the answer is that the experiment has probably 
never been done, since two-level calorimeters are not practical.

-- 

				Craig Werner
				!philabs!aecom!werner
I'll also entertain gifts,knick-knacks,offers of money, & proposals of marriage