Law 1: Determine your body fat
percentage so that we can determine your fat free body mass:
A: Determine Your Body Fat Percentage
We need to determine your body fat percentage so that we can
determine your fat free body mass.
The "U.S Army method" (AR
6009) formulas below are a fairly accurate method to determine body
fat percentage. However, it isn't as accurate as hydrostatic testing
(water dunk tank), which is the gold standard, or a similar high
accuracy method that measures displacement in air rather than water (for
example, the "Bod Pod"). It also isn't as accurate as skin
fold caliper testing if this testing is done by a professional. So,
if you have hydrostatic or a skin fold test result,
you should use that amount as your body fat
percentage.
The "U.S. Army method" body fat percentage
formula for men is:
Men: % body fat = [86.010 x Log (waist – neck)] – [70.041 x Log
(height)] + 36.76
The "U.S. Army method" body fat percentage
formula for women is:
Women: % body fat = [163.205 x Log (waist +
hip – neck)] – [97.684 x Log (height)] – 78.387
If
you don't want to do mathematics, you can temporarily (until we get
one going) use this online calculator (http://lowcarbdiets.about.com/library/blbodyfatcalculator.htm)
to quickly enter in the numbers.
If you want to do the
calculations, you need a "scientific" calculator. Open the
"calculator" on your computer and click on "View" and then
choose "scientific". You'll see "log" among the functions of the
calculator. Do NOT use the "natural logrithim" (LN) key. For men,
take the waist measurement at belly button level. For women, take it at
the point of least abdominal width. For the neck, take the
measurement as low as possible without including any of the trapezius
muscles. Round UP to the nearest .50 when measuring the neck for both
genders. Round DOWN to the nearest .50 when measuring the abdomen for both
genders. Round UP to the nearest .50 when measuring the hips for
females.
EXAMPLE (MEN):
(Neck = 18 in; Waist = 39 in; Height = 72 in)
The
equation for men is: % body Fat = [86.010 x Log (waist – neck)] –
[70.041 x Log (height)] + 36.76
= [86.010 x Log (39 – 18)] –
[70.041 x Log (72)] + 36.76
= [86.010 x Log (39 – 18)] – [70.041 x
Log (72)] + 36.76
A. Enter 18.5 and press the LOG
key. You should get 1.267 B. Enter 72 and press the LOG
key. You should get 1.857
= [86.010 x 1.322] – [70.041 x 1.857] +
36.76
=[113.72] – [130.066] + 36.76 = 15.66 % body fat
percentage
EXAMPLE (WOMEN): (Neck = 14 in; Waist = 30 in; Hip = 40 in; Height = 64 in)
The equation for women is: % body
fat = [163.205 x Log (waist + hip – neck)] – [97.684 x Log (height)] –
78.387
= [163.205 x Log (30 + 40 – 14)] – [97.684 x Log (64)]
– 78.387
= [163.205 x Log (56)] – [97.684 x Log (64)] –
78.387
A. Enter 56 and press the LOG
key. You should get 1.748 B. Enter 64 and press the LOG key.
You should get 1.806
= [163.205 x 1.748] – [97.684 x 1.806] –
78.387
= [285.282]  [176.417]  78.387 = 30.478 % body fat
percentage Determining Fat Free Body Mass
