What is the Origin of Myofiber Growth?

A core concept in muscle physiology and sports medicine, derived from myo (muscle) and fiber, describing the cellular architecture of skeletal muscle. The clinical relevance is profoundly tied to combating sarcopenia, the age-related loss of muscle mass, and metabolic decline.

What is the Mechanism of Myofiber Growth?

Myofiber growth is driven by mechanical tension and metabolic stress from resistance exercise, and it is primarily mediated by anabolic hormones like testosterone and growth hormone. These hormones activate satellite cells and upregulate the synthesis of contractile proteins via the mTOR pathway, leading to the accretion of new cellular material.

Myofiber Growth ∞ Area

Myofiber Growth

Meaning

The physiological process of muscle hypertrophy, characterized by an increase in the cross-sectional area and volume of individual muscle fibers, or myocytes. This process is the structural basis for increased muscular strength, enhanced physical capacity, and improved metabolic health. It is a key anabolic outcome directly influenced by endocrine status.