 After an initial period, in which neuro-muscular adaptation dominates, a process of muscular hypertrophy is observed whereby the size of muscle tissue increases.This increase in size is due to growth from adding sarcomeres (contractile elements) as well as an increase in non-contractile elements like sarcoplasmic fluid.The precise mechanisms which induce muscular hypertrophy are not clearly understood, with currently accepted hypotheses regarding some combination of mechanical tension, metabolic fatigue, and muscular damage as relevant factors.