The Pros & Cons of Hydrostatic Testing

Updated April 17, 2017

Hydrostatic body fat testing measures body mass under water. You weigh on land first and then in the water with a special weighing tank. After controlling for factors like water density, lungs volume, and body density, you get your body fat percentage calculated. This method has advantages and disadvantages.


Hydrostatic testing for body fat is more accurate than other methods, including such as skin fold calipers or electronic devices (bioelectrical impedance) and has the reputation of being the best and most accurate method.


For those with pacemakers, hydrostatic testing is an alternative to electrical impedance devices. A person with a pacemaker cannot be tested using an electrical device because it could cause a pacemaker malfunction.


For athletes, hydrostatic testing could underestimate real body fat percentages. In seniors with osteoporosis the test may overestimate the measurement.

Being Underwater

Hydrostatic testing requires that you stay very still while under water. This can be difficult and can cause panic in some people. You must also go under water several times for best results, which could be stressful for some people.

Access to Equipment

Hydrostatic testing equipment is expensive, so you may not have access to it. Most likely, only colleges, hospitals, research facilities or sports organisations will have the equipment.

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About the Author

Based in Colorado Springs, Vanessa Newman writes for "Women's Edition" magazine and has been published in "Rocky Mountain Sports," "IDEA" magazine and "The Teaching Professor." She has been writing professionally for over 10 years and holds a master's degree in sports medicine. She has written online courses for companies such as Anheuser-Busch and Chevron, but prefers creative writing.