Muscle is a tissue which has the power of contraction. Skeletal muscles are the main muscles for physical activities and exercises. Several changes take place in the skeletal muscles depending upon the type of training which an individual is undergoing. The effects of exercise on muscular system are summarised as follows.
Muscular hypertrophy: Due to regular exercise, training muscles become enlarged. Muscle fibers, diameter and length increases. The total amount of protein, glycogen and enzymes are increased.
Aerobic changes: By training, the amount of myoglobin increases which helps for better supply of O2 to the working muscles of the body. By training, muscles produce energy by increased oxidation of glycogen. A trained muscle uses more fat to supply more energy.
Anaerobic changes: These are the changes which help in supply of energy in the absence of O2.
- Increased lactic acid tolerance
- Change in blood flow of the muscles
- Change in red and white fibres of the muscles
Training and capillary supply: Endurance training increases the capillary ratio (expressed as capillaries per fiber). Training increases capillary density as well.
Influence on performance: As muscles become stronger, they contract with less exertion during a maximum voluntary force. A greater perfusion occurs, and the exercise can be continued without involving the anaerobic metabolism. This would help in delaying the lactic acid accumulation and increase in the muscular force. Strength, flexibility and endurance are increased after the training.
