If you have more muscles, you will have more place to store glucose in them (in the form of glycogen), but what seems to be more important is the rate of glucose uptake by muscles, which increases with endurance training (running, swimming...) rather than with resistance training (body building).
The Role of Skeletal Muscle Glycogen Breakdown for Regulation ...
Studies do suggest the existence of "muscle memory", possibly related to the nuclei of muscle cells (myonuclei). See here for instance. Still, the precise dynamics and hysteresis of strength and their causes do not seem to be fully explored yet.
It is a common myth that egg yolk should not be eaten for bodybuilding. Unfortunately, it is a misguided thing.
Egg yolk contains vitamins and minerals in varying amount.
It raises good cholesterol. Cholesterol promotes more muscle growth. A study showed that those with higher cholesterol levels built more muscle than those will lower levels.
Egg yolks are ...