Son of a bitch! I KNEW we would find something in common! <laughing>

At my lightest as an adult (age 21) I weighted 105, and my normal mass would be about 120-125 without additional work to get lean mass higher (to my current mass of 142).

I think of the terms as simple descriptors of body mass composition.

You're probably technically correct in stating that both the mixed type of genetic body type, while I am speaking more to the phenotype (influences by lifestyle and environment).

I've seen some amazing transformation from what appeared to be a strict ecto to a solid mesomorph that took years to occur. One might expect that if the person stopped working out and reverted in eating habits, that gains might eventually disappear...back to the genetic body comp type.

I agree - the terminology isn't important...its what you do with your genetic and phenotypic potential that counts.