Why and How to Measure Your Body Fat Percentage

Copyright 2006 Lynn VanDyke
Your body fat percentage is one of the best indicators of your fitness and nutrition program. Many people weigh themselves and judge their results on the bathroom scale. However there is one major problem with using the scale to determine your progress.
The best way to illustrate this is by using an example. Let’s say you have been working out for a month now. You initially weighed 160 pounds. You weigh yourself this morning and you are 157 pounds. Your cannot believe that you’ve only lost three pounds! You become frustrated and want to give up.
The scale shows that you lost three pounds, but it does not tell you if you lost fat or muscle. Testing your body fat percentage will tell you how much fat you lost and how much muscle you’ve gained. You see even though the scale says you lost three pounds, you could have lost 8 pounds of fat and gained 5 pounds of muscle. That would equal a net loss of 3 pounds.
As a trainer, I always test my clients body fat percentage. There are three main ways to measure body fat. They are calipers, bio-impedance devices and hydrostatic testing. Hydrostatic testing can be done at universities or hospitals, but tend to be more expensive than most people are willing to pay for a body fat test.
Calipers and bio-impedance, or hand held, devices are more common. Both have a margin of error of about 3-4%. Calipers are better if someone else takes the measurements for you and they are trained professionals. Caliper measurements need to be taken in at least three areas (usually belly, thigh and triceps) and then average them all out to get an overall body fat percentage.
Bio-impedance devices are easy to do by yourself. It takes about 7 seconds for a reading to register. The reading can vary depending on your body's hydration levels, sodium levels, temperature, and a host of other things. There are devices that you can hold in your hands or ones you can step on.
Overall the actual number is not as important as the range you are in. You also want the overall pattern of your body fat percentage to decrease until you are at healthy levels. Calipers and bio-impedance devices will both give you an estimate to as to how much body fat you actually have.
Here are ranges of body fat levels for women:
Essential Fat= 10-12%
Athletes= 14-20%
Fitness= 21-24%
Acceptable= 25-31%
Obese= 32% plus
Here are ranges of body fat levels for men:
Essential Fat= 2-4%
Athletes= 6-13%
Fitness= 14-17%
Acceptable= 18-25%
Obese= 25% plus
*These numbers are according to The American Council on Exercise
Knowing your body fat level is a far better indicator of your progress. It allows you to accurately assess whether your fitness and nutrition program is working for you or against you. Simply using a bathroom scale will not let you know how much fat you have lost or how much muscle has been gained.