Part 2: The Nature of Muscle

Muscles work in pairs. For every movement, as one muscle contracts, an opposite muscle must release to allow the joint to move freely. To bend an elbow, a bicep must contract while a tricep must release. All movement is performed in this manner.

Muscles are made up of many thousands of individual fibers which contract in response to nerve impulse. The strength of an individual contraction is determined by the number of firers innervated. This means that for a muscle to be used to 50% of its total ability, 50% of the fibers are being used totally, rather than 100% of the fibers being used to half of their capacity.

A muscle is born with a set number of fibers. Although they can never be added to, they can be lost due to atrophy. Atrophy can be caused by lack of nerve impulse through lack of exercise or disease, trauma, or the effects of extreme overuse.

The opposite of atrophy is hypertrophy. This is the enlargement of the muscle fibers through exercise. Hypertrophy is what we are trying to achieve through conditioning. Easy exercise will not build muscle. It is only in the last 25% of muscle capacity that hypertrophy will occur.