Body Fat Testing/ Body Fat Monitors



  1. What is important or useful about my percentage of body fat?

A high percentage of body fat is a strong indication of your fitness and health.  The higher your body fat, generally, the less healthy you are.  Carrying around excess body fat causes undue pressure on joints and ligaments.  The excess weight can also put excess pressure on internal organs making it harder for them to work efficiently.


  1. What is a “good” number?

Men should be around 16% body fat and women should be about 24% body fat.  However, the chart below gives a much better idea of what ‘healthy’ or an optimal range is:


  Age Low Optimal High Obese
Female 20 – 39 5 -20 21 – 33 34 – 38 38+
40 – 59 5 – 22 22 – 34 35 – 40 40+
60 – 79 5 – 23 24 – 36 37 – 41 41+
Male 20 – 39 5 – 7 8 – 20 21 – 25 25+
40 – 59 5 – 10 11 – 21 22 – 27 27+
60 – 79 5 – 12 13 – 25 26 – 30 30+
Reading Means:
< 18 Low
19 – 25 Normal
26 – 30 High
30 > Obese


  1. What is the margin of error, and is this the most accurate test?

There are several ways to determine someone’s body fat percentage, the most accurate way is called submersion and is very expensive (up to several hundred dollars) and time consuming.  There are also hand-held devices which are a lot more convenient and while not 100% accurate, they are significantly cheaper (ours is free).  A popular device called calipers, measures the width of folded skin (called a pinch).  In order to use calipers, a trainer must ‘pinch’ your skin with this device in multiple places (leg, upper back, triceps and belly).  Rather than making it uncomfortable for clients to lift their shirts and shorts in order to pinch their skin in the correct places, you may use this electronic device as described below.


  1. How does the electronic device work?

The device we use sends a small electric current through your body to measure your body fat which is the impedance or the resistance to the electric current. The electric current flows through your body using the water within your fat free mass, mainly your muscle. Fat holds a lot of water, so when you have more fat, the current passing through your body easier.  So, based on your height and your weight, which is entered into the device before the test, an estimate of how much fat you hold is determined based on how much resistance the electric current has during the test. What you eat and drink prior to the test can have an effect on the results, but the point is to get an accurate estimate, so you have something to improve on, if need be.


  1. Why are you taking my body fat measurements?

We started this service because we want you to see results, stay motivated, and keep working towards your goals (assuming that your goals are the same as the goals of the boot camp program – body fat reduction, increased cardiovascular stamina, and toning/building muscle).


While the number that you see after taking the test is important, it is not as important as the number you see the next month when you do the test again.  No matter how accurate or inaccurate the device is, the important thing is that your number gets lower each month.  How far it comes down depends upon you, how often you exercise, and what you eat on a daily basis.


Not everyone needs this measurement to help them stay motivated.  We understand that and will not attempt to force anyone to take the test.  However, it is a great tool to help you track your progress, to focus on goals and to measure your improvement. After all, they say that knowing does half the battle; so, knowing where you are and what the ‘optimal’ range is will help you work towards your goals!


  1. What is BMI?

BMI and body fat are supposed to be like measuring inches and centimeters; they are supposed to be different ways of doing the same thing.  BMI is calculated using height, weight, age and gender.  The machine does this but doesn’t take into account any factors that it measures while you are holding it.  There are plenty of BMI calculators you can find on the internet without getting measured for it.


Sarge does not give much credit to BMI because it doesn’t take into consideration how much muscle mass a person has.  A body builder, who is 5’ 10 and weighs 225 lbs would have a high BMI.  The point is BMI isn’t as informative of a measurement as body fat is.


  1. What does all this mean?

Lets say, we have a 200 lbs man who is 10% body fat.  This is someone in very good shape based on the chart above; this means that 10% of his weight is actually body fat or about 20 lbs.  If he wanted to lose 5%, for whatever reason, he would have to lose 10 lbs of fat to get to his desired body fat of 5%.


How long would it take him?


It is safe to lose about 1-2 lbs per week.  Anymore and he is probably losing water and not fat.  So, optimistically, losing 2 lbs per week would take about 5 weeks.


Another example: take a women of about 180 lbs woman who is 33% body fat.  This means that she is carrying 59.4 lbs of fat.  In order for her to reach her goal of 24%, she needs to lose 9 percent of her fat or about 16 lbs.  Optimistically, she could expect to reach her goal in about 8 weeks.