1. Fitness exercise can improve human muscle mass and increase muscle content. The reason is that physical exercise can stimulate muscles, make the synthesis and metabolism of protein in muscles more vigorous, thus promoting the improvement of muscle quality and increasing muscle content.

2. Muscle growth is greatly influenced by acquired factors, so fitness exercise can promote muscle growth and development. The process of muscle growth through exercise is "destruction, repair, recovery, growth and re-destruction".

3. In fact, after the muscle fiber is destroyed by exercise, it will be at a lower level than the original muscle, and its strength and endurance will be affected. At this time, the muscles are in a weak state, and then they will be slowly repaired and restored to the original level, even exceeding the original level. At this point, the muscles are growing.

Extended data:

myoarchitecture

Every muscle that constitutes a motor organ is a complex organ, which consists of muscle abdomen and tendon.

1, abdominal muscles

Abdominal muscle is the main part of muscle organ, located in the middle of muscle organ, which is composed of many skeletal muscle fibers combined by connective tissue. Have the ability to contract. The connective tissue wrapped around the outer surface of the whole muscle is called adventitia.

The adventitia extends inward, dividing muscle fibers into muscle bundles of different sizes, called fiber bundles, and then extending inward to surround each muscle fiber, called endocardium. The sarcolemma is the supporting tissue of muscle, which makes muscle have a certain shape. Blood vessels, lymphatic vessels and nerves enter the muscle with the muscle membrane, which is of great significance to the metabolism and functional regulation of muscle.

2. Tendon

Tendons are located at both ends of the muscle abdomen and consist of dense connective tissue. The limbs are mostly rope-shaped, and the trunk is thin, also known as aponeurosis. Tendon fibers connect the two ends of muscle fibers or run through the muscle abdomen through the intramuscular membrane. Tendon can't contract, but it has strong toughness and tension and is not easy to fatigue. Its fibers extend into the periosteum and bone, making the muscle firmly attached to the bone.

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