It is called body composition of the whole components which form the body mass. This variable is very important for prescribing training routines and to assess progress of the student, patient or athlete.
Body composition can be divided following various models, namely, according HEYWARD and Stolarczyk (2000):
Model 2 components: Fat and Fat Free Mass (MIG);
Model 4 components (Chemical): fat, water, protein and mineral;
Metabolic Fluid Model: fat, extracellular fluid, intracellular fluid, extracellular and intracellular solid solid;
Model 4 anatomical components: adipose tissue, soft tissue (not skeletal muscle), skeletal muscles and bones.
There are several ways to assess body composition, and such methods are divided into three groups: Methods Direct, indirect and indirect Doubly (Martin, Drinkwater, 1991).
The direct method, despite a high precision, has rarely used it consists of analysis is carried out by physical or physico-chemical dissection of corpses.
Indirect techniques are accurate, they have limited practical application and a high financial cost. They are mainly used to validate the doubly indirect techniques. Commonly used for a smaller number of reviews.
Doubly indirect method
Laboratory procedures provide very accurate estimates of the mass of components of fat and fat-free mass being the first choice for the analysis of body composition. However, because of the high cost of equipment, the methodological sophistication and the difficulties involved in the assessed in measurement protocols, their use has been limited. Thus, a greater encouragement to the use of anthropometric method for analyzing body composition because of its simplicity, safety, relative ease of interpretation and smaller cultural constraints (24).
The doubly indirect techniques has less rigor, however have better practical application and lower financial cost, and the best choice for large populations.