Muscles Isolation

Every exercise I do is a favorite isolation exercise, but it’s also a favorite mass-building exercise. I don’t distinguish between the two. My purpose as a bodybuilder is to ensure that every muscle has received its optimum amount of training by the time I’ve finished my workout. That, to me, is isolation.
Somewhere along the way, bodybuilders began to define isolation in what I call negative terms; i.e., the removal of all supporting muscles from the movement, so that only a single target muscle is allowed to contract. If other muscles are involved, they either prevent the target muscle from doing the work or they cause the body to fatigue before the target muscle is fully exercised