Body Composition is a term used to describe the different components that together make up a person's body weight. "Lean" tissues, such as muscle, bone, and organs are metabolically active, while adipose (fat) tissue is not. Several methods exist for assessing the percentage of fat and lean mass of an individual. These methods are referred to as Body Composition Analysis. Body composition analysis can be beneficial for a number of reasons. If one has too much fat — especially if predominantly located in the waist — there is a higher risk for such health problems as high blood pressure, high blood cholesterol and diabetes, which increases risk for heart disease and stroke.
Standard weight scales can delineate a person's total weight, but can't determine the lean-to-fat ratio of that weight. Height and weight charts were traditionally used as guidelines (see Body Mass Index) to determine if people are overweight, but because they don't take into account a person's body composition, such methods as BMI are woefully inaccurate. Some athletes end up falling into the obese category of height/weight tables despite having very little body fat. For example, a person who stands 5'8" tall and weighs 230 pounds, but has only 8% body fat would be considered overweight by the BMI standard.
|Obese||32 and higher||25 and higher|
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Essential Fat and Nonessential Fat
Essential fat is necessary for temperature regulation, shock absorption, and regulation of essential body nutrients. Nonessential fat is the result of taking in more calories than are expended. When nonessential fat accumulates in excessive amounts, and individual may become overfat.
Determining Body Composition
The preferred methods (most accurate) for determining body composition is hydrostatic weighing or hydrodensitometry. However, due to the complexity and complicated nature of these, most physiologists use simple skinfold measurements to determine body fat percent. Skinfold measurements, perhaps the most commonly used method, are accurate up to 98 percent when performed by a skilled tester according to the American College of Sports Medicine.
Another method is through use of bioelectrical impedance. There are a variety of Body Composition and Body Fat Analyzers and Scales available for home use that provide more than just total weight measurements. These devices determine total weight, the percent and amount of body fat, muscle mass, water, and even bone mass. While the readings can be affected by hydration levels, food intake, skin temperature, and other factors, if you follow the directions and take the reading under similar conditions, you will obtain the best results.
- Hydrostatic Weighing - Hydrostatic weighing requires the use of a tank that allows the subject to be measured underwater. The underwater weight is then compared to the dry weight of the subject, taking into account the residual volume of air in the lungs, which affects buoyancy. Because fat is less dense than the other tissues in the body, it floats more easily. The more fat an athlete has, the greater the difference between the dry and wet weights. This is a very accurate measurement, but is time-consuming, labour intensive and not readily available for most populations.
- Bioelectrical Impedence - Bioelectrical impedence measures the level of resistance of electrical current through the body. Since water conducts electrical current well, those tissues with higher water levels (muscle) conduct electricity better than those with lower levels (fat). By determining the impedance to electrical current flow, an estimate is made of the percentage of fat in the body. This measurement is very accurate, but is affected by the level of hydration of the subject, so those subjects who have consumed alcohol, caffeine or have exercised within the previous 12 hours may be dehydrated and results will not be as accurate. Females may get different measurements at different points of their menstrual cycle due to water retention.
- Skinfold Calipers - Skinfold measurements are used to measure the levels of subcutaneous fat at different sites around the body. Common sites used are the triceps, biceps, subscapular, suprailiac and the thigh. The tester measures the site by pinching the fat away from the subject’s body and then placing skinfold callipers halfway between the base and the apex of the fold. A reading is then taken in millimetres. The sum of these skinfolds is then entered into an equation and a body fat percentage obtained. Consistent measurements of skinfold sums are possible, but this requires the location of the sites on the body to be accurately determined, and properly trained and skilled technicians.
Self-administer Skinfold Calipers
Accumeasure calipers are the only body fat calipers that reliably let you test yourself (at the present time). They are extremely simple to use and recents studies show they are relatively accurate. They are recommended by Body-for-LIFE, EAS, and endorsed by the World Natural Bodybuilding Federation.
- ↑ 1.0 1.1 Quinn, Elizabeth (March 17, 2008). Body Composition - Body Fat - Body Weight. About.com. Retrieved on 2008-10-16.
- ↑ American Heart Association (n.d.). Body Composition Tests. americanheart.org. Retrieved on 2008-10-16.
- ↑ 3.0 3.1 3.2 3.3 3.4 Peak Performance (n.d.). Body Composition. pponline.co.uk. Retrieved on 2008-10-16.