💊Daily Pill: Hydrostatic Weighing
Take the plunge
The Daily Pill is a series of very short daily posts where I share the definition of a medical term I think we should all know. Read it every morning and build up your medical vocabulary.
Hydrostatic Weighing
Hydrostatic weighing is a method used to estimate body composition - specifically body fat percentage. The precision is comparable to a DEXA scan. During the test, you will be weighed both in land and in water. You can expect to be fully submerged - typically while wearing minimal clothing and a swim cap. You will need to expel all the air from your lungs and remain still in order to get an accurate measurement.
🤔Why you need to know:
Hydrostatic weighing is the preferred method for athletes and coaches - who typically use this technique to assess the effectiveness of a training program, and for other circumstances where accurate, repeated, and cost effective measurement are required.
Compared to a DEXA scan, hydrostatic weighing is generally more cumbersome for participants, but it is also less expensive and still provides an incredibly high level of accuracy for measuring body fat percentage. While DEXA scans offer the added benefits of detailed bone density analysis and precise information of fat distribution across the body - since you know, it gives you a picture, hydrostatic weighing focuses solely on overall body density to calculate body fat, and its very fast and reliable.
Finding a DEXA scan facility in your area can be challenging - and if your health insurance does not agree to pay for your scan you are going to be out $200-$300. Hydrostatic weight on the other hand is quick and easy, there is no radiation involved, and you won’t need a healthcare provider to administer the test.
Kuriyan R. Body composition techniques. Indian J Med Res. 2018;148(5):648-658. doi:10.4103/ijmr.IJMR_1777_18
🧠Trivia:
This testing modality traces its principles back to ancient Greece with the famous Eureka moment of Archimedes. According to legend, Archimedes figured out how to measure the volume of an object (and thus its density) by submerging it in water while he was taking a bath. This principle laid the groundwork for what would eventually evolve into hydrostatic weighing as a method to measure body density and fat percentage. Im pretty sure there was something about a gold crown in this story too 🤷🏽.