Resistance Training Alters Plasma Myostatin but not IGF-1 in Healthy Men

Abstract

Myostatin may play a role in exercise-induced increases in muscle size, its circulating levels decreasing with resistance training in healthy men. Exercise of the whole body versus the elbow flexors alone did not provide a supplementary stimulus in altering resting plasma IGF-1 or myostatin, or in increasing muscle strength or size. Thus, by default, growth factor responses local to the muscle may be more important than circulating factors in contributing to muscle hypertrophy with resistance training.