Benefits of aerobic exercise
Types of muscle contraction :
There are 2 types of muscle contractions.
1. Isotonic contraction: It involves muscle shortening as the myofilaments slide. This contraction produces normal movements, such as bending the knee, rotating the arms and smiling.
2. Isometric contraction: It occurs when the myofilaments 'spin their wheels' without moving, causing tension in the muscle. This is due to the muscles that are pitted against some more or less immovable object.
Isometric and aerobic exercises
In isometric exercise, muscles are moved through a short distance against a high resistance, as in pushing or pulling an immovable object. Isometric exercise is best for developing large muscles, whereas isotonic exercise has beneficial effects on the cardiovascular system. Isometric exercise-increases the thickness of the muscle fibres and their ability to store glycogen.
The muscle inactivity always leads to weakness and wasting of muscles. Muscles are no exception to the saying 'use it or lose it'. Regular exercise increases muscle size, strength and endurance. There are several exercises according to the needs and benefits. For example jogging or biking results in stronger, more flexible muscles with greater resistance to fatigue. Stamina formation is mainly carried out through aerobic activities, such as running and swimming.
Benefits of aerobic exercise: Physical exercise is a major contributor to health and can improve the body in three ways: more efficient heart, and lungs, improved muscle tone, and more supple joints. It is also essential to prevent obesity. Due to regular exercise, blood supply to muscle increases, it results in supply of more O2. Further aerobic exercises make overall body metabolism more efficient, improve digestion and enhances neuromuscular co-ordination. Heart beat enlarges, so that more blood is pumped out with each beat, fat deposits are cleared from the blood vessels and the lungs become more efficient in gaseous exchange. These benefits may be tempo-rary or permanent on the basis of regular and vigorous exercises. Aerobic exercises do not cause the muscle to increase in size, even though the exercise may go on for hours. Aerobic exercises increase the adaptability of muscles and give greater endurance to muscles. To gain good health, it is suggested that a total of at least 20 minutes per day, of moderate exercise, to burn around 200 calories (837 joules) a day, is required. Regular exercise is preferrable to occasional intense sessions.
The bulging of muscles of a body builder or professional weight lifter results mainly from resistance or isometric exercise in which muscles are pitted against some immovable, or nearly so, object. Endurance and resis-tance exercises produce different patterns of muscle response, it is important to know what your exercise goals are. Weight lift will not improve your endurance for a marathon race. At the same time, Jogging will do little to improve your muscle definition nor will it make you stronger. Proper exercise for proper goal is necessary.