What role does mechanical damage play in the quest for muscle hypertrophy?
First, what exactly is it and how does it occur?
Mechanical damage, or more accurately, microtrauma to skeletal muscle tissue, occurs all the time. Creating high amounts of tension within a muscle, especially through an eccentric movement (lengthening of the muscle under load), or any time we take a set very close to failure can result in some degree of microtrauma in the muscle tissue.
In significant amounts, this can result in soreness from the inflammatory response initiated by the body as it begins the process of healing and repairing these microscopic tears. It is this protective response to damage of the muscle cells that creates cascades of biological reactions and adaptations to occur.
It is important to note that the primary stimulus for muscle growth is, in fact, tension created in the individual muscle fibers (mechanotransduction). This is occurring simultaneously when mechanical damage takes place. They are not two separate things.