Impedance and Phase angle

The impedance is defined as total resistance of a biological conductor on AC and consists of two parts:

Resistance: pure (ohmic) resistance of the electrolytical body water.
Reactance: capacitive resistance, which comes from the capacitor properties of the body cells.

A phase sensitive measurement method is required to separate these two parts, because there is a time difference between maximum of current and voltage in an AC circuit with capacitor. According to the AC sinus form the time difference is measured in ° (degree) and named Phase angle.

Intact and "full" cells with stable membranes show a high Phase angle. But damaged and "faded" cells have a low Phase angle. Therefore the Phase angle is a general sign for the cell density and membrane integrity of the cells. The Phase angle should be over 6.0° for men and over 5.5° for women. Very low values can be a hint of a bad nutritional condition. Then you should go to the doctor.

Overview of ranges used in the GMON

Assessment	Traffic light colour	male	female
critical	red	to 5,0°	to 4,5°
low	yellow	over 5,0° to 6,0°	over 4,5° to 5,5°
good	green	over 6,0°	over 5,5°

Table: Phase angle