Hydrostatic Body Fat Testing…

Also known as underwater weighing/testing or hydrostatic body composition analysis. Hydrostatic underwater weighing has always been considered the “Gold Standard” for body composition assessment.

It is a technique used for measuring the density of a person or the ratio of body fat to lean mass. This procedure is based off the Archimedes’ principle which states that: “The buoyant force of which water exerts on an immersed object is equal to the weight of water that the object displaces”.

Once the body density has been determined, we enter this information into the computer, in which the program works with an equation for estimating the percent of body fat. Because muscle sinks and fat floats, a person with more muscle will weigh more underwater and sink, while a person with more fat will weigh less under water and will be more buoyant.

The process of the test is that we first get your dry weight and height. Enter this information, along with your gender and date of birth. We then will have you get into a BIG bathtub (tank), in which the water is warmed 90-96 degrees. While sitting in the tank, you actually are sitting on a scale. We fully explain the process in which we want you to expel all the air from your lungs, you will fully submerge yourself, hold for 2 seconds, so that we can get a weight reading. We will repeat this 3-4x, in order to get the most accurate reading. This weight reading is then entered into the computer to give you your body fat and lean mass percentages.

The technician will be with you at all times, guiding you through the testing procedure. The water is replaced, treated and heated regularly to meet local health department requirements. A dressing room is provided. Client is asked to bring their own bathing suit and towel.

Following the testing session, your technician will review your results, offer some suggestions and send you an email version of the report. This report includes your percentages, along with your resting metabolic rate, an approximate daily expenditure and information that can help guide you on your health, fitness and nutritional journeys. Your testing sessions are always kept on file and each time you return to test, you will see your past results, so that you can compare from test to test.