Body fat and lean tissue mass (primarily muscle mass) in terms of percentage as pounds may be determined through several methods.
Skinfold thickness through measurement with calipers are quite accurate, nearly equally the results from that of the gold standard of underwater weighing (UWW), or the newer technology of Dual-Energy X-ray Absorptiometry (DEXA) scanning (a procedure primarily for the purpose of measuring bone density). Skinfold measurement is my method of choice when appropriate, based on it's accuracy and relatively simple procedure.
Bioelectrical Impedance Analysis (BIA) may be an accurate alternative, however careful attention must be paid to the client's water level as results are strongly affected by hydration status. This method does have the benefits of being non-invasive and quick. A small electrical impulse is send through your body (so small that you do not even feel it) and the speed at which it travels provides an estimation of the ratio of fat-to-lean tissue in your body.
