Bio-impedance technology (BIA) cannot measure muscle mass, instead it is estimated by some calculations based on different metrics. After numerous tests, we realized that the results were biased because the organs were included. We have decided to use Lean Body Mass (LBM) as it is a more accurate calculation (LBM = weight – body fat) since BIA body scales are primarly designed to measure body fat. To track your muscle mass, watch your Lean Body Mass progression as it is composed of everything that is not fat in your body: bones, skin, organs and muscles. From this list, only your muscle mass is likely to change. If you want to gain muscle mass, watch for the LBM curve to go up.