Why can swimming shape people's beautiful figure and bring them health and happiness?
We know that the resistance of water is more than 800 times that of air. When swimming, people paddle with their arms, pedal or save the water with their legs, and even all the muscles of the neck, chest, back, waist and buttocks participate in coordinated movements. According to the law that the speed of fluid mechanics is proportional to the square of resistance, if the moving speed of human body in water increases by two times, the resistance will increase by four times. Because of this, the faster the swimming speed, the greater the resistance, which will stimulate the cerebral cortex and reflexively mobilize more muscle groups, thus promoting the unified and orderly movement of the whole body muscles, especially the pectoralis major, deltoid muscle, triceps brachii muscle group and upper body and back muscle group. At the same time, swimming is a periodic exercise mode, and tension and relaxation are alternately carried out rhythmically. In this way, muscles will become soft, tough and elastic.
When the human body floats in the water, the joints of limbs and spine will not be subjected to physical hard impact from the surroundings during the movement, and will not cause any damage to the body, and it is beneficial to exercise the flexibility and flexibility of the skeletal system and better promote the development of bones.
The density and heat transfer performance of water are greater than that of air, so it consumes more energy than other sports. The experiment shows that the heat consumed by staying in water at 12 degree for 4 minutes is equivalent to that consumed by staying on land at the same temperature 1 hour. It can be seen that under the same time and intensity, the heat emitted by water is much greater than that on land. The energy consumed in exercise is constantly supplemented by sugar and fat in the body, so regular swimming will gradually consume excess fat in the body and promote muscle development. Fat people insist on swimming for about half an hour every day, which can quickly achieve the dual effects of losing weight and bodybuilding. Thin people insist on swimming, which will increase appetite, improve digestion and absorption function, and gradually become plump and strong.
Because the water temperature in swimming or in rivers, lakes and seas is lower than that on land, it has a direct effect on improving human blood circulation, increasing the nutrient supply of subcutaneous tissues, promoting the secretion of sebaceous glands, and thus improving human immunity against diseases. At the same time, the flow of water also has a good massage effect on the skin, which will make the skin more elastic and shiny. Children often swim, which will promote bone calcification and effectively prevent rickets and rickets. Swimming is more effective in the adjuvant treatment of chronic diseases. Because the chest and abdomen are under the pressure of water, the respiratory muscles move passively, which is beneficial to the rehabilitation of patients with bronchitis and emphysema. Swimming also has a good regulating effect on the central nervous system, and can quickly eliminate symptoms for people with forgetfulness, insomnia, depression and neurasthenia. For the elderly, improving cardiopulmonary function and cerebrovascular microcirculation and delaying aging is one of the best exercise methods.