KGO TV Channel 7, San Francisco, is reporting about BOD POD, a body composition measuring device. The system was used at this year’s NFL combine and is also used in the clinical facilities.
The company (Life Measurement, Inc. of Concord, California) explains the workings of its plethysmograph device:
The BOD POD technology is fundamentally the same as underwater (hydrostatic) weighing, but uses air instead of water. The BOD POD measures the volume of air a person’s body displaces while sitting inside a comfortable chamber, rather than measuring how much water their body displaces when dunked in a tank. By using air instead of water, the BOD POD offers a fast, safe, and easy-to-use tool for measuring body composition, without sacrificing accuracy.
Since it is based on the same whole-body measurement principle as hydrostatic weighing, the BOD POD first measures the subject’s mass and volume. From these measurements, whole-body density is determined. Using this data, body fat and lean mass can then be calculated.
The BOD POD itself is a dual-chambered, fiberglass plethysmograph that determines body volume by measuring changes in pressure within a closed chamber. The front, or test chamber, has a seat that forms a common wall separating it from the rear, or reference chamber. The door to the front chamber is secured by a series of magnets during the brief data collection period. The BOD POD also has a large acrylic window, providing the subject with a wide field of view, making the test process a comfortable and enjoyable one.