It still amazes me when I get evidence showing the large number of people who consider their body weight to be the cornerstone indicator of their fitness level. They talk about the weight they once gained and the amount of it they’ve since lost. They’ll often mention wanting to “get back to the weight they were in high school.” They gleam proudly while sharing that the dial on the scale displayed a weight loss of five or ten pounds in the past month. In other words, many mistakenly obsess over the total size of their bodies rather than honing in on the fat/lean tissue ratio of which that size is composed.
Let’s not deny that checking our weight on a scale can tell us some of the story and that it’s normally our most convenient indicator of whether we’re shedding body fat. When we lose fat, we lose weight – and vice versa. However, it’s important to always keep in mind that it is “body composition” (our ratio of lean tissue to fat tissue) that matters most and the best way to determine it is to ‘measure body fat percentage.’
In my opinion, checking this ratio becomes even more important with age. Something called sarcopenia sets in and ensures that we lose muscle mass steadily if we don’t actively build it. This means that if you strive to get down to that beloved body weight that you held in your high school days, it’s unlikely you’ll look as appealing if you merely possess ten pounds less muscle while carrying ten pounds more body fat. By contrast, a gain of ten pounds of muscle with a simultaneous loss of that much body fat will probably have a more positive effect on your body’s appearance and performance than dropping even as much as twenty pounds of fat with no replacement or gain of muscle.
We can best improve what we can first measure. Take time to 'measure body composition.' It's beneficial whether you want to get super-lean or simply lose a bit of fat while gaining or maintaining muscle mass.
That said; let’s get to the important topic of how to ‘measure body composition.’ The way it’s done is by first finding out how much of our body is composed of fat (by percentage) – then using that number to determine how much lean body mass we’re carrying. In order to look and feel better, we want to increase that lean body mass number and minimize fat mass percentage. The first step in doing that is to find out where we presently are so that we can determine where we want to go.
‘How to Measure Body Fat Percentage’:
It’s important to note that “body fat testing” is always estimation because a test that’s one-hundred percent accurate does not exist. Some test methods, like hydrostatic, are known to be more accurate than other methods that are more questionable, such as BIA body fat scales and hand grip tests.
Put simply, the most precise method for measuring body fat percentage is the hydrostatic (underwater weighing) test while the most convenient is by use of a BIA hand grip apparatus. The best method for combining practicality with reasonable accuracy is through use of skinfold calipers; the “pinch-an-inch technique.” The skinfold caliper test can actually be nearly as accurate as underwater weighing if a highly practiced and skilled tester is handling the calipers.
Here is more of an explanation of these three methods for ‘measuring body fat percentage’:
Underwater Weighing (Hydrostatic)
You might want to bypass this method if you have any aversion to holding your breath underwater with absolutely no air in your lungs. Sure, it’s only for a few seconds. However, that few seconds of desperately wanting to breathe can possibly be repeated several times if you’re working with a test professional that has little experience.
This test method works on the basis of buoyancy. Since fat floats and lean body mass sinks, hydrostatic testing requires being submerged in water while sitting or lying on a scale. Basically, the more body fat we carry – the more buoyant we will be and the less we will weigh on that scale. The more lean body mass (including muscle) that we have – the less buoyant we will be and the more we will weigh on the scale. After three or four good readings are taken (with all air exhaled from the lungs), the numbers are averaged out for a more accurate estimation of body fat percentage.
Pros: Typically more accurate than any other method devised.
Cons: Inconvenient and somewhat costly, making it impractical to test frequently.
Since most of our body fat is stored subcutaneously (just below the skin), skinfold measuring is fairly accurate considering the practicality of this test method compared with underwater weighing. Several locations on the body are used to pinch the folds of skin and fat with a hand-held vice-like tool called a skinfold caliper. By measuring the thickness of the fat folds in these places (abdominals, thigh, hip, bicep, triceps, calf, etc), the reading in millimeters can then be plugged into a formula to get an estimate of overall body fat percentage.
If you use this method, I highly recommend you have someone who is skilled with this testing do it for you. Ensure that they use the same calipers and the same formula every time they take readings. This will ensure accuracy and consistency.
Pros: Easy, practical, economical.
Cons: Less accurate than hydrostatic. Accuracy is even more questionable with an unskilled tester.
BIA Hand Grippers and Scales
Years ago, when I first shed fifty pounds of fat and went from my blubbery former self to my current lean condition (my before/after pics are right here), I browsed my way in to a home gym equipment store where the clerk shoved a body fat testing hand gripper in front of me. I was proud to get a body fat reading of eight percent on the spot. Had I known at the time how far off the readings on these devices can be and how much they can fluctuate, I might have tempered my pride with a dose of skepticism?
BIA (bio-electric impedance) scales and hand grippers measure body fat by testing the electrical conductivity of the body’s lean mass. Since lean tissue (muscle, bone, connective tissue) holds a much higher water content than body fat, it’s claimed that these devices can measure the percentage of body fat by sending a very low amperage of current through about half of the body; the lower body when using the scale and the upper body with use of the hand grippers.
One major drawback of this method of ‘measuring body fat percentage’ is that the readings tend to fluctuate with the body’s hydration levels. This makes it important to take several readings throughout the day so as to get a running average.
Pros: Most convenient method; can be done in the privacy of home.
Cons: Typically the least accurate method.
“Measuring Body Composition”: What to do with the fat percentage number
Once you’ve determined your body fat percentage, it’s time to use that number to discover the exact number of lean body mass (LBM) pounds you’re carrying so that you can set goals to increase that number while decreasing your percentage of body fat.
Calculating your LBM consists of a very simple formula whereby you only need your total body weight and your body fat percentage (the number you got from “dunking”, “pinching”, “gripping”, or “stepping”) to figure it out.
Simply change your body fat percentage number into a decimal – multiply it by your total body weight – and then subtract that resulting number from your total body weight number.
You weigh in at a strapping 205 lbs.
Your body fat percentage is 19% (.19)
.19 x 205 lbs. = 38.9 lbs.
205 lbs. – 38.9 = 166.1 lbs
… So you’d have 166.1 lbs. of LBM (81% of body weight)
Just for fun – let’s look at what would happen to this example of body composition if we were to add ten pounds of muscle while losing ten pounds of fat. Of course, in this scenario, body weight would remain the same while body composition would change drastically – resulting in a much more appealing appearance:
171 lbs. ÷ 205 lbs. = 83.4% LBM
28.9 lbs. ÷ 205 lbs. = 14% body fat
So that’s how you “measure body composition.”
… And don’t let the naysayers tell you that you can’t gain muscle and lose fat at the same time. I explain how I’ve done it right here.