I’m always nervous about using the word “normal” to describe most things. As silly as I am, I realize that one person’s wacky is another person’s normal, and so on. However, when we’re talking body mass index, or BMI, it’s perfectly acceptable to use that word.
As of last night, my weight is 144, which puts me, with my 5’4″ height, at a BMI of 24.7%, which is in the normal range. While this is certainly something to celebrate, I know that BMIs can be deceiving. For example, my trainer, who looks like she could compete in bikini contests, told me that her BMI is in the obese range. It’s no myth that muscle weighs more than fat. In addition to personal training, my trainer teaches upper level fitness classes throughout the day; the girl is solid muscle and healthy as a horse. The BMI scale is meant to be used as a general guide, but not as a complete decoder of fitness. Though my BMI may be normal, it’s not a true indicator of my level of health or fitness.
To better understand one’s personal level of fitness, the true ratio of muscle to fat must be obtained. This can be done in several ways. Most of us
remember the skin-fold test with calipers from gym class. They’re somewhat accurate, but do involve some math and other than balancing my finances, I try to avoid math at all costs. My bariatric doctor measures muscle to fat ration with body fat scales that use an electric current to gauge the amount of lean mass, water, and fat in your body. These are also fairly precise, however, the reading can fluctuate depending on your personal hydration level. My trainer uses a hand-held device that operates in the same way, with the same chance for inaccuracies based on hydration level.
Another way to measure body fat is by a complicated machine called a Bod Pod. My daughter actually did this for extra credit in a fitness class at her university. Her school had just acquired one of these expensive little ditties and wanted volunteers to test it out. The Bod Pod works by measuring the volume of air you displace inside of the pod. The Bod Pod then does a complex mathematical equation (ARGH! Math, again, but the machine does it for you) to measure your fat, lean muscle mass, and resting metabolic rate. It’s extremely accurate, and used by athletes, but certainly isn’t easily accessible to the average person.
The dunk test is another very accurate method of measuring body fat. My daughter did this one, too. She’s a glutton for extra credit! The dunk test involves jumping into a pool while sitting on a special stool, in a crunch position so your body is entirely immersed. Then, you exhale as much air as possible and remain completely still as the machine weighs you. This is also really accurate, but, like the Bod Pod, it can be difficult for the average person to access.
The ultimate in body fat testing is the InBody. This is the latest technology and can be found in some fitness centers, like Lifetime Fitness. Using the InBody is as easy as standing on a metal platform and holding onto two handles for about one minute. This measures your body fat percentage, tells where your fat is stored and where you have water collecting in your body. It also measures the general strength of each of your limbs–which is pretty cool!
Though I’ve only experienced the less accurate methods of body fat testing, their results are close enough in telling me that I still have plenty of work to do. According to the Body Fat Percentage Scale, for a woman of 50, my fat percentage should be less than 30% at the highest end of the range. I’m at 38% right now and still concentrating on building muscle to be at a healthy body fat range. (When I began my fitness journey, my fat percentage was 67!) My muscular trainer, whose BMI tells her that she’s obese, has a very healthy fat percentage of 22% and is considered lean. Having a normal BMI is awesome, but I think we have to look beyond the BMI, because it isn’t always an indicator of how fit and healthy a person is.
What do you think? Does a healthy BMI mean a healthy person? What’s your favorite way to burn body fat?