Body Composition. Body Composition. Definition: describes the percentages of fat, bone, muscle, and fluid that make up body weight. Because muscular tissue takes up less space in our body than fat tissue, our body composition, as well as our weight, determines leanness.
Two people at the same height and same body weight may look completely different from each other because they have a different body composition.
Easy to use once skill has been mastered
Does not require much time
Inexpensive way of estimating percent body fat
Technical sources of error
Mostly concerned with subcutaneous fat (under the skin)
May not be an ideal measurement for those who are obese and very leanAdvantages and Disadvantages
Requires little or no technical knowledge of the operator or the client
Testing itself takes less than a minute
The unit can be easily transported from place to place
Requires only an electrical outlet and the machine itself
This method has a higher standard error range than most people desire
Tends to consistently overestimate lean people and underestimate obese peopleAdvantages vs. Disadvantages
This method is currently considered the "gold standard" in percent body fat measurement
Repeat measures usually prove consistent, and can be used to chart progress
This method usually requires a lot of equipment and space
Testing is time consuming and involved
Requires in-depth knowledge to administer the tests and compute the calculations
Being submerged under water may be difficult and produce anxiety for some
How accurate is it?If each test is performed correctly according to the recommended guidelines, there is a +/- 1.5% error. (Note: Accuracy depends on the client’s ability to blow all the air out of their lungs both during a pre-test screening with a spirometer, and during the test itself. Since air makes the body float, inability to perform either of these maneuvers will result in miscalculation of the percent body fat.)
Does not require much skill
Procedure is less invasive than skinfold testing and may be better accepted in some districts.
Estimates based on height and weight such as BMI result in 5% to 6% error because body weight reflects muscle and bone mass and not just fat mass.
Body mass index is not the recommended procedure for determining body composition because it does not estimate the percent of fat.
It merely provides information on the appropriateness of the weight relative to the height.BMI