Most people gauge their weight loss success with the bathroom scale. Step up, stand still, and blam instant feedback. However, your common household scale is about as reliable as a drunk plastic surgeon at Lollapalooza.
Countless variables can cause your scale weight to fluctuate throughout the day. The scale measures your total weight, but doesn’t provide a measurement of how much actual body fat you’re carrying.
There are a few methods you can use that will tell you how much body fat you have.
Bioelectrical Impedance allows you to take your body fat measurements into your own hands.
You’ll find these handheld devices in about any nutrition store or Amazon. They’re the most non-invasive way to measure bodyfat.
It works by shooting tiny electrical pulses through the body, don’t worry you will never feel these. The device then measures the amount of time it takes for those impulses to return. Fat slows down the movement of the impulse, the less fat you have the faster the impulse returns.
Remember that scene in Thor: The Dark World where Natalie Portman’s character was laying on a weird Asgardian table? The Asgardian doctors said it would scan Natalie Portman’s character’s body from head to toe to diagnose her affliction. Minus the cool “magic of Asgard” this is pretty much how a DEXA scan works! Lying on a table, you’re scanned like a sheet of paper in a copier. Different types of X-Rays shoot into your body to measure how well your body absorbs those rays.
As the DEXA scan passes over each part of your body, it measures and determines the fat in your legs, arms, chest, etc. By scanning over every body part, it provides a larger picture of your overall fat deposits and better measures your lean mass.
I’m gonna keep the nerd references coming because hydrostatic weighing looks like that scene from Empire Strikes Back where Luke is in the medical tube after Han saves his life on Hoth.
The first step of hydrostatic weighing is to measure your body weight completely dry. The second step dunks you into a giant tub of water. Your bodyweight is then measured in the water. The attendant then determines the density of the water and calculates your overall body density. Then with some fancy math formulas, the doctor can determine your body composition.
This is by far the strangest of all the machines… You look like you’re stuck in a giant egg. BOD Pods are similar in concept to hydrostatic weighing, however, instead of water BOD Pods use air to measure your body fat.
The Pod is filled with air and the amount of air your body displaces is measured.b With the density of your body determined the doctor uses a few formulas to determine your body composition.
These are those weird crab claw, pincher-type devices you might have seen in a gym or a doctor’s office.
For calipers, you need to take skin measurements at different points around the body. Men need to be measured at the abdomen, chesticles (pecs), and thigh. Women take measurements at the tricep, thigh, and abdomen.
In the terms of accuracy and which one of these measures your body fat to the closest degree, they all fall short and suffer from their own inherent errors.
US Navy Standard
This method is by far the cheapest and non-intrusive, and there aren’t any outside factors that could cause errors. The US Navy’s way of measuring body fat is by using a tailors tape.
You’ll take your sex, weight, height, and then measure your waist at your navel and the narrowest part of your neck.
Get your bodyfat per the Navy’s guidelines using this calculator: http://fitness.bizcalcs.com/Calculator.asp?Calc=Body-Fat-Navy
How Much Body Fat Should You Have?
Body fat measurement is different than the standard BMI (body mass index) that you’ve probably heard about for years. BMI measures the ratio of your height to weight. It doesn’t tell you how much body fat you actually have.
However, according to The American Council of Exercise these are the ranges that men and women can fall into:
|Obese||32% plus||26% plus|
One important factor to keep in mind with body fat measurements is that some of these methods have higher error rates than others. You could do three different versions and have three different readings.
Body fat is great to know as a measurement of progress but like the scale don’t let it overtake your life and become another thing you stress about. To keep yourself sane, measure once every 4-6 weeks.
Focus on lifting more weight, hitting your nutrition, and getting plenty of sleep and the fat will come off.