Measurement Tools — Underwater Weighing


What It Is

The percent body fat is calculated from equations based on the density of the body. The density of the body is calculated by an equation that involves measuring a person suspended on a trapeze in the air and then weighing the person under water.

Equipment Used

Special weighing scale and submersion pool or tank

How It's Done

  • The person is seated on a special scale, is submerged in a tank of water, then exhales as much air as possible.
  • S/he remains motionless while underwater while the underwater weight is recorded.
  • This procedure is repeated two to five times to get a dependable underwater weight score.
  • Body density and then percentage of body fat are calculated from the reading

Pros

  • It was considered the accepted reference method for many years.

Cons

  • The equation is based on studies of standard, young Caucasians. Modifications in the equations may be necessary for other ethnicities.
  • Some people feel uncomfortable when they must be fully submerged, leading to incorrect readings.
  • The procedure requires an experienced operator.
  • There is always air left in the lungs. It is difficult to accurately correct for this.
  • It does not take into account the location of the body fat.

Take Our Survey

survey

We need your help! Periodically we conduct a survey of our visitors and use the results to help guide our planning process for future programming. We really want to know what you think, and your answers will help us improve the Shape Up America! organization. Please take a few minutes to share your questions, thoughts and ideas. Your responses will be kept strictly confidential.

Btn Click Here

Donate to SUA

donations

Please consider a donation to Shape Up America! Your tax-deductible contribution helps us develop new initiatives to address the problem of obesity in America.

Btn Click Here