By Michael Krueger
Many people that I’ve trained over the years have said that they aren’t concerned about knowing their body fat percentage. They say that since the measurements aren’t all that accurate to begin with, why should they bother? I don’t force the issue since, to some extent, they are correct. There are many ways to measure body composition, with some being better than others.
Of course, there are reasons, both personal and practical, that you might want to know where you stand, and keeping track of that number can help you have some quantifiable information with which to analyze your progress.
So, what are the different ways of measuring body composition and which one should you use?
Methods of Measurement
There are basically five ways to get a body fat estimation, and as long as you stick with the same one, or an average of a couple, you can get a good idea of whether you are going up or down. Some of the best ways to measure body composition are done only in laboratories, which while more accurate aren’t very convenient for regular checkups.
Using a skin fold calipers is cheap and,l for the most part, easy. The problem is that technique is important, since you always need to measure in exactly the same spots–and that can be problematic. Learning to take skin fold measurements takes many hours of practice to get to the point where the person doing the pinches is accurate and consistent and the results are repeatable. So depending on the level of expertise, even if the same person regularly does your pinches, your results may vary widely month to month. Using the calipers on yourself can be quite difficult, so finding someone to do the pinches is preferable. If you know someone who has the qualifications and experience to accurately perform a skin fold test, it’s is a reasonably good way to keep tabs on your body fat percentage.
Bioelectrical Impedance is a simple way to measure fat, since all you need to do is step on a scale or take hold of the sensor grips on a handheld device. The trade-off for this simplicity is accuracy. The accuracy can be affected by numerous factors, the biggest of which is hydration. In fact, hydration is such a major factor that I use my scale mostly to track my hydration level. I have used this scale long enough to know at what level of hydration I feel and function best. If you are going to use one of these scales, I recommend having a specific protocol that you follow. Always weigh in on the same day, same time, same fluid and food intake, and same level of activity prior to taking the reading. Then if your hydration isn’t at its optimal level, the rest of the results should be disregarded, since water is what the test is really measuring and therefore the results will be inaccurate.
Bottom line, if used consistently and with a good protocol in place, you can get an idea of whether you are gaining or losing fat or lean mass or if you are just dehydrated.
Now on to the methods you can’t do yourself, starting with Hydrostatic Weighing. Basically in this protocol you are dunked in a tank and weighed underwater. By inserting your dry land weight and your underwater weigh into a specific equation, this method can provide a good estimation of your body composition.
The downsides are you need the equipment, the personnel, the equation, and a big pool to do this test. For me, the biggest drawback is that before you go under the water, you must forcibly exhale as much of the air from your lungs as possible … not my idea of fun.
The next one is Dual-Energy X-ray Absorptiometry or DEXA. This is basically a full body x-ray and is by far the most accurate way to measure your total body composition. It’s incredibly easy for you since all you need to do is lie on a table while the x-ray machine does its thing. The results can be broken down into bone density, lean tissue, and fat.
The downsides are where to get this done and how much it costs. I don’t know the answer to either question, but I’d bet that not many places do it and it would cost a fair amount of cash.
Finally, there is Air-Displacement Plethysmography, which is a lot like hydrostatic weighing, but it uses air displacement instead of water. The results are quite similar to and about as inconvenient to administer as hydrostatic weighing and probably more expensive.
So, there are the five ways that body composition is generally estimated. I tend to say estimated since only the DEXA test is really, really accurate. All the others use an equation of some sort to work out the numbers, and the testing procedure as well as the performance of the test subject will affect the outcome.
The Mirror
The simplest and perhaps best tools you can use in monitoring your body composition are a full-length mirror and a digital camera. I know many people who avoid these mirrors at all cost and the thought of taking a full-body photo in unflattering bathroom light is completely abhorrent to them. Well, the mirror doesn’t lie and the photo won’t let you forget, so this is a good place to start your quest for increasing your lean mass, decreasing your body fat, and getting the body you desire.
The moment of truth in front of the mirror starts with simply relaxing. This is not the time to suck in your gut or puff out your chest; just stand naturally and let it all hang out, so to speak. Do you like what you see looking back at you? Perhaps not so much, but don’t just look at the flaws; look at the good stuff as well. If you have been working out, you should be able to see some muscle definition and some new lean mass as well.
Check out your legs: Can you see definition in your quadriceps? How about your chest? Can you make your “pecs dance” or do you have the dreaded “man-boobs”? Take a second mirror and look at yourself from the back, and yes, take another photo. Do you have the desired “V” shape or more of a “pear” shape from your shoulders to your waist? Is your butt sagging and do your legs look spindly? Now back to the front: With both hands, about two inches to either side of your navel, grab whatever flab you can and give it a shake; how much is it? Remember, if it jiggles, it is fat. Now take a good look at your face; just because you see it every time you shave doesn’t mean you look at it critically. Do you have a double chin? A triple chin? Are your eyes bright and sparkly or dull and lifeless? Most importantly, are you smiling at what you see?
After you get dressed, sit down and take a look at the photos you took. If you are pleased with them, you are in a great place! Keep up the good work! If you are less than pleased, it’s time to make some plans to improve your image. Don’t be discouraged or disgusted by what you see, since this is simply where you are now and no amount of wailing and gnashing your teeth is going to change that. This is just the starting point for the journey to an elite level of fitness.
Six Months from Today
Download those photos to a special file or, better yet, go old school and get them printed. There’s nothing like a hard copy to ground you in reality. Take those photos and put them where you will see them every day or at least every time you work out.
Next spring, take some new photos to compare with the ones you took today. You will go through the same “mirror, mirror on the wall” shtick and be honest about what you see.
If you train hard and consistently between now and then, you will see some major changes in your mirror, the most important of which just might be the big smile looking back at you!
Michael Krueger is an NSCA-certified personal trainer. He got his start in fitness training while serving in the United States Coast Guard. He works with firefighters and others in and around Madison, Wisconsin. He is available to fire departments, civic organizations, and athletic teams for training, consulting, and speaking engagements. He has published numerous articles on fitness, health, and the mind-body connection and was a featured speaker at the IAFC’s FRI 2009 Health Day in Dallas, Texas. E-mail him at MKPTLLC@gmail.com.
