alan shepherd
Century Rider
Only those who risk going too far, can find out how far they can go.
Posts: 175
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Post by alan shepherd on May 3, 2009 20:21:38 GMT -6
Dear Lurch,
I rode today in the rain and was wondering about the cumulative effect of moisture loss/gain. Is there a direct linear relationship between the amount of rain collected on my person and the amount of sweat expelled from my rather large frame?
Thanks, Ward Cleaver
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Post by Lurch on May 4, 2009 12:51:01 GMT -6
There is a relationship, but it may be counter intuitive. You probable know that your sweat is a result of your body trying to cool itself done, and you might think that if a little sweat (water) is good then more would be better and that might or might not be true. In thermal dynamics energy moves from hot to cool, and the reason your sweat works is it is evaporating and in the state transfer it is pulling the energy (heat) with it, but if you add more water, like in a heavy rain your cooling system becomes saturated and the water actually acts more like an insulator rather than a conductor for dissipating the body's heat to the air. The marine corps. had a similar idea back in the 90's. To help with recrutes dealing with heat they placed sprayer that the recruits could run through to cool off and keep PTing. They had an increase in heat related problems with recruits and the sprayer are no longer used. Now if instead of using air we use water for our cool sink then, although we have again saturated the cooling system with water we have also switch to a more efficient medium for dissipating heat i.e. using water rather than air, as long as the water is within a certain temperature range. This is why swimming is not a real great way to loss weight and also why swimmers prefer almost cold water for swimming long events. another interesting note, in another study endurance runners were giving various treatment for dealing with heat on a sunny day, and group that used sun screen showed a significant reduction in bodily temperature, although I'm not sure if was surface or core, but still one would think of sun screen as having more of insulating effect rather than cooling. Thanks for your question Mr. Ward and say hi to your beaver for me.
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