Adaptation in muscle cells, as in any system, starts with a stimulus (like exercise) that creates a demand for a response.

A cell can indeed be viewed as a highly organized, self-replicating pattern of atoms and molecules that takes in energy to sustain, organize, and replicate itself.

Metabolic reactions contains anabolic - synthesis and catabolic - analysis reactions.

Battling entropy - energy to sustain for disintegration is the main task of the cell.