[Sportsandrec] Body measurements and stuff...

[Thornbury, Kelly]

Another easy method for monitoring body measurements is to find an outfit 
(shirt and pants) that "almost fits...While measurements are a useful 
diagnostic tool, do you really care, or will you notice a difference 
between, 100cm and 99.5 cm??? No. On the other hand, you will probably feel 
a greater sense of accomplishment once you diet and exercise yourself into 
that outfit you've been wanting to [get back] into.

The water submersion method used to be the gold standard (the tests by which 
other tests are compared) for body composition, but the best measurement now 
is a DEXA (Duel Energy X-ray Absorptiometry) scan. This is a "low energy" 
x-ray (about 100th the energy of a normal x-ray, or about the same radiation 
as spending an afternoon in the sun at higher altitudes), originally 
developed to measure bone density.

Having performed both tests for a number of years, the DEXA is far more 
accurate, being able to tell you the body composition of your left arm as 
compared to your right. Water submersion is far more complicated, much 
easier to get inaccurate results from tester error, and the results are 
effected by residual lung capacity (the air in your lungs you can't expel 
and is almost impossible to measure accurately) and gasses trapped in your 
digestive tract. A DEXA scan can tell you not only your bodyfat percentage, 
but muscle mass, bone mass, and far more than merely the difference between 
your weight in and out of a tub of cold water. Plus, many subjects are not 
able to stay calm and completely exhaled under water long enough for an 
accurate weighing.

If your goal is to improve your body composition (I don't like the "lose 
weight" terminology), will any of the results from any of these tests really 
help you...probably not. If you feel you need to change your body 
composition, spend less time worrying about the numbers and just get out for 
that walk, jog, swim, or bike ride. "Less planning and more action."