These days it’s all about the benchmarks. It’s not enough to just look good and feel healthy. People want to know they’re doing well, want to be able to chart their progress, compare stats. What’s the national average for somebody of my age and sex? Should I be benching more? Running further? What’s my VO Max, my optimal heart rate, my cholesterol level? And perhaps the biggest one of all: am I fat? That’s the one that gets the most attention. Everybody knows whether they’re fat or skinny or just average, but somehow, that vague sense of place is never enough. How fat am I? Am I on the skinny side of normal, or on the healthy side of skinny? Luckily, for those curious people there are several methods to choose from, ranging from the Body Mass Index to the Body Fat Percentage. Which should you use? Read on, gentle reader, and find out.
The first and easiest is the controversial Body Mass Index. Formulated over a hundred and fifty years ago by a Belgian genius called Adolphe Quetelet (hence why it’s also called the Quetelet Index), it was launched into superstardom status in the 1970’s by a scientist called Ancel Keys who coined the name and said it was the best substitute for body fat percentage among rations of height and weight when used for population studies. How does it work? Take your weight and divide it by your squared height. So if you weight 175lbs and are six feet tall, you have a BMI of 23.1 You then take your number, check it against the chart, and find out if you’re underweight (BMI < 18.5), normal (BMI between 18.5 and 24.9), overweight (25-29.9) or obese (BMI > 30). Simple, right?
But that’s the problem, it’s too simple, and that very simplicity glosses over a host of complications and problems. BMI was only meant to be used as a substitution for body fat percentage, and only applied to inactive individuals, not athletes. Say you’re a pro-football linebacker. Your BMI is going to tell you that you’re obese. Or say you’re an old fellow who’s lost height as he ages: your BMI would go up even if your weight remained the same. For that reason people heavily criticize using BMI as an individual measure of your health-it’s too simple, general, and doesn’t take into account the realities of each person’s situation.
So that leaves us with body fat percentage, the original gauge that your BMI was meant to replace for convenience. Instead of weight divided by height squared, it’s the weight of your body fat divided by your total weight. See how that might be more accurate? How do you figure that out? There are two ways. You can go to a science lab where they’ll either shine an infrared light through your bicep and determine your % by how much light is reflected, or perform a dual energy X-ray absorptiometry, or a host of more complicated means, OR you can just measure your skinfolds at home with a caliper. I think we both know which option you’re going to take.
The skinfold method is simple, relatively precise and very easy to do. You just pinch a fold of skin from certain standardized points on your body and measure the thickness of that fold with calipers to determine the subcutaneous fat layer thickness. These measurements are then turned into a percentage through some equations, leaving you with a good idea of what your percentage is. Best of all? It’s incredibly cheap and easy compared to going to the science lab.
Philip Tucker is a Fitness Product Review specialist for Miami based Extreme Fitness Results LLC. Visit Extreme Fitness online to learn more about fitness and weight loss programs like Slim in 6 and the P90X Workout.