What fluid type constitutes the majority of total body water?

Dr William Sheldon describing the three basic human body types viz the Endomorphs, Mesomorphs and the Ectomorphs. Although these types are genetically determined, the key lies in identifying where your body type lies or if it is a combination of any two and then understanding what type of work out would be suited to your need. The types are classified keeping in mind an individual's metabolism rate and bone structure.