Thursday, March 18, 2010

On hydration and being fat

Warning - I will be writing about proper hydration, and as any fitness person knows that means discussing what happens after proper hydration.

I've finally gotten back on track with watching my diet, and as such have seen my weight start heading back down. After a couple of days though I noticed something odd - my body fat % (measured by bio-electrical impedance) was climbing. Climbing at a rate of 1.0 to 1.5% a day. Keeping in mind that my scale reports in 0.5% increments this still seemed like a lot (not to mention odd) so I looked up the impact of hydration (lack of) on this sort of measurement. Short version, the worse your hydration is the higher your apparent body fat %, because it screws with the conductive properties of non-fat body mass.

Since I was already in "fun with Google" mode I decided to see what I could find about "proper" hydration. Sure, I've heard the old "8 x 8 oz glasses per day" thing, but it has always struck me as odd that my wee little friend Pest, who's maybe 5 feet tall in heels and weighs significantly less than I do, would need the same amount of liquid as me. The old stand-by is "clear and copious" urine and I knew I was failing that test, but the closest thing to a formula I found was to halve your body weight in pounds to get the number of oz of water you should drink. A little math gives us:

275/2 = 137.5

For comparison - 8 x 8 = 64

So, I need to be drinking not 8 8 oz glasses, but 17.

No wonder my body fat % has been climbing. I've made the effort for the last couple of days, managed to get close to 80 oz each day (and that was rough) and the body fat % has started reversing. Keeping up this level of drinking (water) is going to be tough.

1 comment:

  1. I would just suggest being careful with that consumption amount. You don't want to fall into this state: http://en.wikipedia.org/wiki/Hyponatremia

    There is also this take on it: http://ajpregu.physiology.org/cgi/reprint/00365.2002v1 - though that is abut 50 pages worth of reading.

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