It is common to read that the bioelectrical impedance (BIA) calculation for Fat Free Mass is derived from Total Body Water, based on the assumption that fat-free mass (FFM) comprises of 73.2% of water, so the mass of this compartment can be calculated from TBW.
The fat mass (FM) is obtained by subtracting FFM from the total body mass.
The BIA devices that use this method to predict TBW do not take into account the variability of water fraction in the FFM compartment and also the variability of the remaining protein and mineral content.
In athletes, the water percentage tends to have a high variability which does not fall into the 73.2% assumption used. Bodystat therefore, has developed our own algorithm to calculate TBW and FFM, and do not use the 73.2% method.
This makes Bodystat unique in the development of its own proprietary algorithm for Fat Free Mass and an algorithm for Total Body Water assessment. Accurate assessment in these areas are particularly important within the sarcopenia and elderly population groups.