How do I interpret the BIVA?

Bioelectrical Impedance Vector Analysis (BIVA) presents information on Total Body Water and the phase angle in a single diagram. This allows the doctor to assess the patient's hydration status, nutritional status and fitness level. By considering these values together, the doctor can distinguish, for example, an overhydrated patient with heart failure from a bodybuilder.

While the amount of body water is identically high (a bodybuilder's body water is elevated because muscle contains 75% of intracellular water), the bodybuilder has a high phase angle and the patient with heart failure has a low phase angle, given the overhydration in the extracellular area.