Get Dunked

Hydrostatic body fat testing, or underwater weighing, is a method of determining body composition (body fat to lean mass) that makes up a person's total body density using Archimedes' principle of displacement. It has been considered the gold standard for body composition assessment for the last 20 years and really is the best way to learn more about your body.

Underwater weighing is based upon the principle that states that, “The buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object. One can use this principle to determine a person's percentage of body fat, because the density of fat mass and fat-free mass are constant. Lean tissue, such as bone and muscle, are denser than water, and fat tissue is less dense than water.”

Essentially, muscle sinks, and fat floats. Therefore, a person with a higher body fat percentage will weigh less underwater and be more buoyant. Someone with more muscle will weigh more underwater and will sink toward the bottom of the pool.

To perform underwater weighing, a person is first weighed on dry land. Next the individual will get into a large tank of water or a pool. While sitting on a special scale, he or she is lowered underwater and asked to expel all the air from his or her lungs and remain motionless while the underwater weight is measured. This procedure is repeated two or three times and averaged for the most accurate result.

“I was really nervous the first time I went through the underwater body fat testing,” says Anna Gonzalez, a Cupertino resident. “It was such a strange sensation—you have to exhale completely before entering the water, when, naturally, there is a feeling to inhale and get all the air you can before submerging yourself into the water.”

A special calculation is then used to figure out lean weight versus fat weight in order to determine a person's percentage of body fat. By volume, fat weighs less than muscle, and pound for pound, fat and muscle each have a constant mass and displace a specific amount of water.

“With hydrostatic body fat testing, I’ve gotten the most accurate results, which have helped me reach my goal of losing 22 pounds,” says Gonzalez. “There is no frustration like when I use my bathroom scale—the facts are facts with underwater weighing, so whether I’m retaining water because it’s that time of the month, or not, I know I will still get real results.”

Personally, I would not have my body fat tested any other way. Hydrostatic testing is by far more the most accurate and reliable. I don’t know about you, but when it comes to body fat, I want to know the truth. With this method, there are no excuses.

From mobile lab to permanent lab, there are several locations in the Bay Area where you can get your body fat tested with this high-tech, surefire method. This is the way of the future. Are you ready to get dunked?

Use the following links to get you started:

FitnessWaveNorCal.com, mobile hydrostatic body fat testing clinic has several upcoming test locations as follows:

7/22/11  Club One, Almaden Valley, San Jose

8/13/11  CrossFit, San Jose, Campbell

8/15/11  Evolution Trainers, Mountain View

BodyFatTest.com, mobile hydrostatic body fat testing clinic (locations vary through out the Bay Area; check website for up to date accurate information).