The whole body air displacement plethysmography is using air displacement technology for measuring and tracking body fat and lean mass. For this procedure you would need a BodPod by life measurements instruments, concord, CA. This machine measures the body composition by determining body volume and body weight. You cannot exercise for the two previous hours because you have to be fully rested and hydrated. Your body weight is measured by using scales, and body volume is measured by first measuring the volume of the chamber while empty then the volume of the subject chamber is measured with the subject is inside. By subtraction, the volume of the subject is determined. Once those body volumes are determined, the body density can be computed and inserted into an equation to provide percent fat measurements. The advantages are a high level of accuracy, ease for use, and fast test time. It is well suited for children, obese, and elderly, and disabled persons. I think that this is a good procedure, but the only bad thing is that the machine used for this procedure is very expensive, like 30 to 40 thousand dollars expensive, and I don’t really have that much money to be spending on that, so an alternative is using under water weighing, even though you get wet it costs a lot less than buying a BOD POD.