Bioelectrical impedance analysis (BIA) is a widely used technique for estimating body composition and it is particularly useful in large, population-based studies because it is quick, portable, inexpensive and noninvasive. Using the resistance and reactance measurements of the human body in tetrapolar mode and in multi frequency from 1 to 500 KHz, the appropriate algorithms issue from the peer reviews will allow the estimation of the body composition.
In the human body, low resistance is associated with large amounts of fat-free mass and low fat mass . High resistance is associated with smaller amounts of fat-free mass and high fat mass
In the human body, high reactance is associated with large amounts of body cell mass (intracellular mass) and low ECW (Extra Cellular Water) . Low reactance is associated with smaller amounts of body cell mass and high ECW.