During training, our muscles sustain minor damage, known as microtears. When this happens, our body sends inflammatory cells to the injured site to repair, heal, and eventually grow the muscle. You have to break your muscle down to build them back up.
When we lift weights, we inflict microtrauma on the muscles we work on, known as muscle injury or damage. This activates stem cells, known as satellite cells, to multiply at the injury site. Following proliferation, satellite cells either fuse to form new muscle fibres or fuse with the existing muscle fibre to promote an increase in muscle fibre cross-sectional area or hypertrophy. Satellite cells are responsible for maintaining muscle mass, regeneration, and hypertrophy.
Growth factors that drive satellite cells to increase the muscle fibres' size are hormones or hormone-like substances. It has been demonstrated that these growth hormones influence muscle growth by controlling satellite cell activity. The two most important factors that encourage muscle growth are testosterone and insulin growth factor (IGF)-1, particularly mecho-growth factor (MGF).
When lifting weights, most people focus on the hormone testosterone. There is some truth to the notion that testosterone boosts protein synthesis, prevents protein breakdown, activates satellite cells, and incites the production of other anabolic hormones. Strength training helps release more testosterone and makes the receptors of your muscle cells more responsive to your free testosterone. However, most testosterone (up to 98%) is bound in the body and hence is unavailable for usage. In addition, by increasing the number of neurotransmitters at the damaged fibre site, testosterone can also trigger growth hormone responses, which can assist in activating tissue growth.
By promoting protein synthesis, enabling glucose uptake, redistributing the uptake of amino acids (the building blocks of protein) into skeletal muscles, and, once more, activating satellite cells to boost muscle growth, the IGF controls the amount of muscle mass growth.
Muscular hypertrophy occurs when muscle protein synthesis outweighs muscle protein breakdown. Resistance training can damage or harm the cellular proteins in the muscle cells, causing the satellite cells to become activated and start physiological reactions that promote muscle growth and repair. The following are ways to create damage, stimulate muscle repair, and produce hypertrophy:
But just as with other types of tissues, once the “bigger” muscle has adapted to the amount of weight and the damage it’s subjected to, it will again be in a state of equilibrium; that is, protein synthesis equals protein breakdown. So to inflict hypertrophic adaptation, we have to break this protein balance. Therefore, we need to repeatedly find ways to challenge our muscles to keep them growing, such as employing various techniques, changing the speed of each lift, or trying out new exercises.
However, inflicting “good” muscle damage alone will not cause muscle hypertrophy. There are three mechanisms by which our muscles grow, and muscle damage is one. The other two are mechanical tension and metabolic stress.
You have to break a muscle down to build it up. For most weight lifters, this is an already known fact, but for newbies, this can be new and exciting information and, in fact, a surprising one. If done with appropriate load and intensity, the muscle damage or microtears you get from exercise will eventually form a more immense muscle mass.
But are there ways to speed things up and have a quick and effective muscle recovery, so you’ll see training results fast?