The human skeleton is covered by approximately 650 muscles, which create the distinct contours and shape of the human body. Anatomists disagree on the exact number of muscles. The main area of controversy concerns whether certain muscles are one unit or two units working together. (Clearly we did not evolve to please anatomists.) It is generally accepted, however, that there are at least 630 muscles in the human body. By contracting and relaxing, these muscles produce movement.
Although bodybuilding helps strengthen bones, ligaments and tendons, it is the muscles that receive the greatest benefit from this sport. The words bodybuilding and muscles go hand in hand. Muscles show the results of your labor. You don’t ask a person to show you his Achilles’ tendon – you ask to see his biceps. Muscles are the symbol of strength, even though strength relies on tendon power and leverage as much as muscle power. The associated ligaments and tendons are forgotten in the excitement – until you pull one.
There are three types of muscle tissue: cardiac, smooth and skeletal. From a bodybuilding standpoint we are concerned with the third type, so we will be brief when describing the first two.
1) Cardiac muscle
Cardiac muscle is found only in the heart. Its main function is to force blood through the body’s arteries, veins and capillaries. Smooth muscle makes up the walls of such internal hollow organs as the small and large intestines, the respiratory tract, and most of the reproductive system.
2) Skeletal muscle
Skeletal muscle acquired its name because, for the most part, it is attached to the body’s skeleton. This type of muscle is often said to be striated because of the alternating dark and light areas. (Smooth muscle is nonstriated, while cardiac muscle is finely striated.) Unlike smooth and cardiac muscle, which contracts involuntarily (i.e. you have no direct control over it), skeletal muscle contracts voluntarily in most cases. This means you can contract skeletal muscle whenever you want.
Skeletal muscles are covered and held together by fibrous connective tissue called fascia. Fascia can be divided into two types – superficial and deep. Deep fascia is composed of layers of dense connective tissue and is found between individual muscles and groups of muscles. As does superficial fascia, deep fascia contains an assortment of nerves, blood vessels and lymph vessels