What is a Muscle?
A muscle is a bunch of fibers. These fibers are made up by actin and myosin filaments. They are connected to bones by tendons and by contracting allow biomechanical movements. They vary in composition between diverse grades of fast twitch and slow twitch muscle fibers. The former is more suitable for power activities the latter endurance activities. They have different forms of pennation, or arrangement patterns. They activate via an electro-chemical mechanism. The brain sends commands through the central nervous system. The central nervous system relays these commands through motor neurons within the muscle and the muscle activates. The muscles in turn, in particular muscles called proprieceptors, can send information back to the brain.
How Does a Muscle Get Bigger?
The process by which a muscle gets bigger is called hypertrophy. There are two types of hypertrophy, myofibrilar hypertrophy and sacroplasmic hypertrophy. Myofibrillar hypertrophy is when the muscle fibers are broken down and grow back with a slightly increased cross sectional thickness. This is brought about by lifting weights with a suitable volume, or amount of repetitions. The idea is to breakdown the fibers to the point of microtrauma. If a muscle is broken down to a point of macrotrauma muscle soreness and injury is often the result. This is why suitable split timing of body parts and exercises is crucial.
Sacroplasmic Hypertrophy or "The Pump":
Sacroplasmic hypertrophy is the pump. In other words the muscle is gorged with blood and various hormones or endocrines. It is important that a bodybuilding regime allows for the correct load and rest periods to promote anabolic hormones. Anabolic, which just means growth, substances are testosterone, human growth hormone and igf-1. If the bodybuilder trains
beyond the pump or up to the point of failure it can promote catabolic, or breakdown, hormones such as cortisol.
How Does a Muscle Get Toned?
There are various myths about tone but it is actually very simple. Tone is just a sign that the brain, the central nervous system and the muscle's motor unit are ready to fire at anytime. The safety catch is always off so to speak. This can be achieved two ways. High intensity (heavy) weight training. Or slow high volume weight training where muscles become accustomed to extended periods of time under tension. Competitive gymnasts display the kind of tone that is achievable when the two forms of training are combined.
How Does the Muscle Repair itself?
A muscle repairs itself mainly via protein intake. Proteins are made up by chains called peptides. These peptides are collections of aminos. An amino is a nitrogen bearing molecule. This is why you have often heard the importance of amino acids and protein with connection to muscle growth. They are fundamentally the same thing. The reason why protein quality is important, is
that the body needs essential amino acids. These are amino acids which the body cannot synthesise itself. However if overall diet isn't healthy and sleep isn't adequate muscle growth is negligible. The body wont grow new muscle bulk if it's worried about just staying alive. So to grow muscle a bodybuilder must get adequate sleep, hydration and nutrition. Bodybuilding can be healthy despite what certain people might have you believe.