Percent Body Fat Measurement
Determining your body composition allows you to make appropriate decisions regarding the diet and exercise program that is best for you. Beyond that it is the most useful way to measure the progress in changing your fat to lean ratio. Hydrostatic weighing is the most accurate method to measure body fat composition. Also referred to as "underwater weighing," this technique requires the individual to be weighed on land and under water. Percent body fat is calculated using a complex mathematical equation. Hydrostatic weighing is the gold standard for body fat measurement because research using the "tank" has been replicated and repeated most accurately using the ultimate test subject--a cadaver! In fact, the most common question professionals ask is how closely other methods correlate to this protocol. The down side to hydrostatic weighing is that it is time-consuming, requires expensive equipment, and relies heavily on the expertise of the technician performing the test. Therefore, other methods are more commonly used. The second most popular method for determining body composition is skinfold measurement. The technician uses a caliper to measure skinfold thicknesses at various sites on the body. The caliper also has limitations. Make sure you find an experienced technician to avoid errors. Individual differences such as age, gender and fitness status make it difficult to determine norms for a large population.
Other methods developed in recent years include ultrasound, bioelectrical impedance, arm x-ray, and computerized tomography. None of the research on these methods compare in accuracy to hydrostatic weighing, mostly because it's difficult to replicate results. Nonetheless, the accuracy of body fat measurement is of dire consequence only to the avid athlete. The "scale" is the most popular method for measuring land weight, but you don't find people running around asking which scale is the most accurate. Like land weighing, body fat composition is most useful to monitor your progress. Any method, used on a repetitive basis, provides an accurate benchmark to measure progress. Regardless of which method you choose, test yourself or get tested on a monthly basis, using the same protocol and the same technician. If you are working out regularly and eating healthily, you'll experience a satisfying decline in the fat to lean ratio and move rapidly to your goals.