Analysis (BIA) is another method of estimating body fat. BIA evaluates changes in electrical conductivity in different body tissues. This method is a safe, noninvasive, and rapid way to assess body composition. However, there are limitations to this method due to changes in the hydration and electrolyte levels of individual subjects. It is best to use other methods other than bioelectrical impedance to measure body fat percentage.
How this test works
The instrument sends a signal from one part of your body to an electrode on your hand. A slower signal indicates that your body may contain more fat. A faster signal shows that you have a higher lean muscle composition. This is due to the fact that muscle contains 70% water while fat contains much less between 5 and 13 percent.
The disadvantage of this method is the high margin of error. An extremely fat or lean individual may show a reading that’s higher or lower than the actual body fat percentage. How hydrated your body is also can affect the results since more water make the signal move faster throughout your body. It’s best to stay hydrated at the right level for the best measurement.