Swimming is one of the most popular fitness exercise programs. Proper swimming exercise not only brings psychological pleasure and creates a smooth and graceful body shape, but also enhances the functioning of the cardiovascular system, strengthens the body and improves coordination. Many sports are prone to cause strain or injury to the organism, but swimming is the sports activity with the lowest rate of strain and injury. Therefore, swimming is a good, lifelong exercise fitness exercise. 1, improve the function of the cardiovascular system The cardiovascular system includes what we know as the heart, lungs, and blood vessels responsible for transporting inhaled oxygen to muscle cells. Swimming to overcome the resistance of the water needs to use more energy, so that the heart rate increases, cardiac output increases. Adhere to long-term swimming exercise, the heart volume is athletic increase, myocardial contraction, quiet heart rate slows down, per-pulse output increases, blood vessel wall thickening, elasticity increases, the efficiency of the cardiovascular system has been improved. In addition, when swimming, the human body is in a lying position, the pressure of water on the skin and the formation of a massage effect, therefore, the limbs, especially the lower limbs of the blood to the heart of the reflux is easier than on land in an upright state. And the resistance of the water makes it difficult for the muscles as on land for explosive force, these characteristics are very suitable for middle-aged and elderly people to exercise, not only to enhance physical fitness, but also not easy because of the movement is too intense and accidents. 2, improve the function of the respiratory system One of the main features of water is difficult to compress. Because the density of water is more than 800 times greater than air, the pressure in the water is much greater than in the air. This is the reason why beginner swimmers find it difficult to breathe in the water. As the chest and abdominal cavity in the water by the pressure increases, which forces the respiratory muscles with greater force to breathe. So regular swimming increases the strength of the respiratory muscles and improves the functioning of the respiratory system. One of the most obvious examples is the value of lung capacity. The lung capacity of swimmers can reach 4,000 to 6,000 milliliters or even 7,000 milliliters, while the average person has only 3,000 to 4,000 milliliters. 3, improve the ability of the muscular system Swimming is a whole-body participation in the sport, can mobilize more muscle groups than other sports to participate in the metabolic energy supply. Although swimming can not shape thick, bulging muscles, but can improve the strength and coordination of many muscles, especially the trunk, shoulder girdle and upper limb muscles. Because swimming in water requires overcoming a high level of resistance and swimming is a cyclical exercise, long-term exercise can result in improved muscle strength, speed, endurance and joint flexibility. Another great benefit of swimming is improved flexibility. This allows people to continue swimming even when they are unable to engage in other physical activities due to age limitations. People who engage in regular swimming activities become more flexible and supple due to the greater range of body movement during swimming. Moreover, proper swimming technique requires muscles to elongate before contracting and exerting force, and this type of exercise is conducive to the continuous improvement of flexibility and strength. 4, so that the proportion of body composition is more reasonable, so as to shape a fit body If you often watch swimming competitions, you will be envious of the swimmers that rounded, slender, properly proportioned muscles and fit body. Because of the way their muscles work, swimmers generally have a trim figure, broad shoulders, flexible waist, and well-proportioned body shape. Some may say, I want to lose weight through swimming, why is it not effective? In fact, in order to lose weight through exercise, it is necessary to achieve a certain level of intensity, adhere to a sufficient amount of time, and be persistent. If you just go to the swimming pool for three days to fish and two days to swim a little leisurely, of course, it will not have any effect. If running, cycling or any other exercise in this way, the result is the same. 5, to improve the mechanism of thermoregulation As the temperature of the water is generally lower than the air temperature, the thermal conductivity of the water is dozens of times stronger than the air, so people in the water to lose heat far faster than in the air. Regular swimming can improve thermoregulation, and thus more able to withstand changes in external temperature. Especially winter swimming, the improvement of this aspect is particularly obvious. 6, prevention of disease, treatment and rehabilitation Due to the stimulation of cold water, long-term swimming exercise can enhance the body to resist the cold, the ability to adapt to the environment, can prevent colds and other diseases, so that the body is increasingly strong. As the body lies flat when swimming, coupled with the role of buoyancy, can make the spine fully extended, some spinal patients have a certain role in rehabilitation. Swimming can also be used as an exercise prescription to treat some chronic diseases, such as chronic gastrointestinal disease or chronic bronchial asthma and so on. For some people who are not suitable for upright exercise, such as patients with excessive obesity, etc., if you take running and other ways, due to gravity, the legs and feet are overburdened, which can easily lead to injuries. At this time, swimming is a good alternative to exercise. 7, honing will, cultivate attention quality, promote mental health and intellectual development Learning to swim needs to overcome certain difficulties. For example, people who learn to swim for the first time are generally afraid of water, and the unfamiliarity of the water environment makes them fearful. Learning to swim is the process of overcoming fear and difficulties such as coldness and tiredness, which is a good exercise for one’s will quality. Modern people seek to return to nature, more and more people like to swim in open water, to rivers, lakes and the sea to enjoy the fun of nature, and many people insist on winter swimming all year round, all of these have honed the will of people and inspired the spirit of people. Swimming is also good for the development of intelligence. The flowing characteristics of water put forward many special and subtle requirements for swimming techniques. The process of mastering swimming technique is a process of full coordination between the nervous system and the muscles, and requires the experience of a special “water sense”. These are benign stimuli for the nervous system, and those who continue to swim will certainly benefit from them.