Measuring body composition using bioelectrical impedance is simple and easy. Electrodes pass a very weak electrical current through the body (you cannot feel it) to test the resistance to current flow. Electricity moves faster through muscle and bone than it does through fat. The device measures this difference to calculate how much fat you have on your body.
Types of Measurement Devices
Handheld (upper-body)-Enter you weight and height and hold the device at arms length while gripping both hand grips. These models will give a good percentage body composition. However, it can only measure body fatness in the upper body because it dosn’t have electrodes for the feet. Electricity flows up one arm, through the chest, and down the other arm. It misses the entire lower body, therefore, it probably won’t give an accurate measurement of your fat loss around thighs, hips, abdomen, and lower body.
Lower Body- This is basically a scale with electrodes for each foot. It works well, and it is very simple to use. With this type, electricity passes up one leg, through the abdomen, and down the other leg to the second electrode. This model could slightly overestimate body fat percent because most people have more fat around the hips, abdomen, and thighs.
Full Body Composition- The most accurate type of bioelectrical impedance testing device available. It has electrodes for the hands and feet making the electrical current pass through the entire body. This is how bioelectrical impedance testing is done in a medical lab setting. With this type you can accurately measure changes in body fat throughout your entire body as you progress through a fitness program.
Other Options for Measuring Body Fatness
Skinfolds- Requires a skinfold caliper; pinch the skin in several sites on the body and use the caliper to measure the thickness. Use the Jackson Polluck equations to estimate percent body fat based on the thickness of the skinfolds. These calipers are highly accurate, and give a reliable clinically accepted measure.
Body Mass Index (BMI)- The Body Mass Index does not measure percent body fat, but it is a ratio of weight to height. BMI= (weight(kg)/heigh(in meters) squared) It is used to classify a person as being underweight, normal, overweight, or obese. However, since it cannot measure body composition (percent fat) it is no the perfect measure.
Body-Girth Measurements- Use a tape measure to determine the circumference of your body at different points and plug those numbers into equations to estimate body fatness. This also does not measure body composition, therefore it is a loose guide. The waist-to-hop ratio compares the circumference of your waist to the circumference of your hips. This number can be used to predict disease risk because internal body(inside the body cavity) fat is more dangerous than fat that is right under the skin.
One of the most popular bioelectrical impedance measuring devices, this handheld system is easy to use and can provide a decently accurate measure of your percent body fat. It has several setting you can choose from depending on whether you are an athlete or not.
This system measures fatness throughout your entire body. It is designed to pass electrical current through your hands and feet. This allows it to measure body composition throughout a large portion of your body.
This device has a high weight capacity, and it measure your percent body fat and weight in one compact device.