Physique, build, habit, constitution all mean bodily makeup or structure or organization peculiar to an individual or to a group or kind of individuals.
Physique applies to the structure, appearance, or strength of the body of an individual or of a race and may connote such qualities as capacity for endurance, stamina, or predisposition to disease.
Build, though often interchangeable with physique, may distinctively suggest not so much the makeup of a body as its conformation; it tends to call attention to such qualities as size, structure, and weight and rarely when used of man or an animal to health or the lack of it.
Habit implies reference to the body as the outward evidence of natural or acquired characteristics that suggest the nature of one's physical condition and capabilities; thus, a full habit suggests an appearance marked by stoutness, redness, and congestion of the visible blood vessels.
Constitution applies to the makeup of the body, especially of an individual, as affected by the complex of mental or physical conditions which collectively determine its state (as of healthiness) and its powers (as of endurance and resistance).