What about this Pellius:
In the bodybuilding and fitness community and even in some academic books skeletal muscle hypertrophy is described as being in one of two types: Sarcoplasmic or myofibrillar. According to this hypothesis, during sarcoplasmic hypertrophy, the volume of sarcoplasmic fluid in the muscle cell increases with no accompanying increase in muscular strength, whereas during myofibrillar hypertrophy, actin and myosin contractile proteins increase in number and add to muscular strength as well as a small increase in the size of the muscle. Sarcoplasmic hypertrophy is greater in the muscles of bodybuilders while myofibrillar hypertrophy is more dominant in Olympic weightlifters.[26] These two forms of adaptations rarely occur completely independently of one another; one can experience a large increase in fluid with a slight increase in proteins, a large increase in proteins with a small increase in fluid, or a relatively balanced combination of the two.
https://en.m.wikipedia.org/wiki/Muscle_hypertrophy
This is very similar to what Mentzer was taking about in the vid Vince posted when dismissing the need for large amounts of protein to grow muscles as muscles are not composed primarily of protein but of water. He speaks about how low carb/high protein diets "dry out" the muscle makes you looking drained and flat. Higher carbs and properly hydrated muscles are able to store more glycogen making you appear larger and fuller. This is one of the reasons insulin is used. You can force more glycogen into the muscle forcing larger size but often to the point where you get that bluffy marsh mellow look of a Phil Heath rather than the dense hard muscle of a prime Mentzer.
We've all experienced the over night growth and fullness after a night of pizza and brownies. Our muscles look pumped and full. But is that real muscle? Real lean muscle fibers? I mean a super hydrated muscle fiber versus a dried out ketosis ridden fiber is still the same muscle fiber. We know only amino acids, not glucose, can build real muscle fibers. That's why they call it protein synthesis and not glucose synthesis.
So, I'm really not sure. I know at this point, I would rather have nice plump, full muscle fibers even if it's "artificially" pumped up hydrated fibers even if it's not true myofibrillar hypertrophy. But ideally I would rather not to have to even think or worry about it. I would rather be in the ignorant bliss of a Coleman doing the same old bench, incline, dumbbell flies that generations have been mindlessly following and still produce some of the largest pecs ever seen on a human being.
It seems only the genetically less fortunate hash out these things over and over trying to find a way to compensate for our lack of muscle hypertrophic predisposition.
