Measuring Body Fat
Measuring Body Fat
The American Dietetic Association recommends that men have 15-18% body fat and women have 20-25% body fat. Healthy male athletes might be as low as 5-12% body fat, and healthy female athletes could be as low as 10-20%.
Dr. C. Everett Koop breaks down healthy body fat ranges by both gender and age. Men under 39 years of age should have 8-19% body fat, and women under 39 years of age should have 21-32%. Older men may range from 11% to 24%, and older women may range from 23% to 35%.
There are 3 main methods used to calculate body fat:
1. Hydrostatic Weighing
2. Skin fold Calipers
3. Bioelectrical Impedance
Each of these methods has its advantages and disadvantages.
Hydrostatic Weighing
This is a fancy way of saying underwater weighing. Hydrostatic weighing is one of the more accurate ways to measure your body fat. This is how it works:
" In order to use this method, you sit on a scale inside a tank of water. Then you blow out as much air as you can.
" After you are dunked under water, you blow out even more air.
" Fat is lighter than water so the more fat you have, the more you will float. Hydrostatic weighing measures underwater weight to figure out body density.
" Accuracy (about 2 to 3 %) depends upon the amount of air you expel. If your don't blow out all of the air, it won't be as accurate.
" This is a difficult way to measure body fat. It is uncomfortable and scary for many people to be dunked underwater with no air in your lungs.
Skin fold Caliper (Pinch Test)
The skin fold caliper measures skin fold thickness from several areas of your body. This is how it works:
" An expert pinches your skin at different areas and measures them with calipers.
" The results are plugged into a formula to determine your body fat.
" A skin fold caliper is not usually as accurate as hydrostatic weighing because it depends on the skill of the tester to separate your fat from your muscle. It also depends on finding the right spots to pinch.
" The results can also be distorted if you're older because fat moves inward with age.
" This is one of the more accessible ways to check body fat and is generally painless.
Bioelectrical Impedance
This is one of quickest methods of testing body fat using a BIA (Bioelectrical Impedance Analysis) Scale. This is how it works:
" When you use a handheld BIA scale or stand on a BIA Scale, a signal passes from hand to hand or from foot to foot.
" The more muscle you have, the faster the signal travels.
" The fact that water conducts electricity gives you your results. Muscle is about 70% water while fat contains almost no water.
" This method can be accurate with about a 4% margin of error. However, the results are affected by skin temperature, hydration, and food intake. If you're dehydrated, you will not get an accurate body fat percentage.
Using a BIA scale is an easy way to test body fat. Be sure you test at the same time of day each time that you test. To obtain the most accurate results, it is best to test the first thing in the morning before breakfast after drinking a glass of water.
