It's too hot. Is swimming good for the human body?

The specific benefits of swimming are as follows: 1, resisting cold and adapting to temperature changes. The contraction of body surface capillaries stimulated by cold water and the reflex relaxation of skin capillaries caused by hypoxia during exercise are repeatedly experienced by people who often participate in swimming, which can greatly enhance the flexibility of nervous system to control the contraction and relaxation of skin blood vessels, and also greatly enhance the ability of human body to adapt to temperature changes and resist cold. 2. Enhance cardiopulmonary function. Compared with ordinary people, people who swim for a long time have better cardiopulmonary function. This is because the massage effect of water flow on the horizontal human body greatly improves the speed of heart blood return, and the whole body exercise strengthens the blood transfusion to the heart and brain, which is conducive to the prevention and treatment of cardiovascular diseases. In addition, the burden of respiratory muscles increases greatly when swimming, and the water pressure of 12- 15 kg compresses the whole brain cavity, which is helpful to increase the vital capacity. 3, body shaping and beauty. Swimming can exercise the muscles of the whole body in a comprehensive and balanced way. In order to overcome the resistance of water, people need to consume a certain amount of calories, so swimming can gradually reduce excess fat and effectively exercise the muscles of the chest, back and limbs. Swimming can be called an aerobic exercise in water, which can keep people healthy. 4, calcium supplementation and skin care. When swimming outdoors, the sun shines directly on your body. 7- dehydrocholesterol will be converted into vitamin D in the body to promote calcium and phosphorus metabolism. Vitamin D can also prevent calcium deficiency and rickets, which is beneficial to the growth and development of human body, especially children. Frequent outdoor swimming can increase the contact frequency with fresh air, water and sunshine, and also protect the skin and prevent skin diseases. Influence on cardiovascular system: Swimming plays an important role in improving cardiovascular system. The stimulation of cold water can promote blood circulation through heat regulation and metabolism; In addition, the pressure and resistance of water also play a special role in the heart and blood circulation. When swimming on the water, the water pressure on the body has reached 0.02-0.05 kg per square centimeter. When diving, with the increase of depth and the change of physical conditions, the pressure will increase, and the speed of swimming will also increase the pressure load. The muscle tissue of atrium and ventricle can be strengthened, the volume of heart cavity can be gradually increased, and the beating times of heart can be reduced. This can preserve the activity of the heart, but it can improve the whole blood circulation system. When resting, systolic blood pressure increases, systolic blood pressure decreases, and blood pressure value becomes more favorable. The elasticity of blood vessels has also improved. According to the statistics of relevant experts, the average person's heart beats about 66-72 times per minute in a quiet state, and the stroke output is about 60-80 ml, while those who take part in swimming exercises for a long time contract about 50 times under the same conditions, but the stroke output reaches 90- 120 ml. Influence on respiratory system: During swimming practice, without a large amount of oxygen supply, the metabolic process and cardiovascular system can't be saved. However, because water compresses the chest and abdomen, it is more difficult to inhale. Someone has done special experiments. When swimming, people's chest is under the pressure of 12- 15 kg of water, so in order to get enough oxygen for the body, the respiratory muscles must constantly overcome this pressure. In addition, when swimming, exhalation is generally done underwater, and the density of water is much higher than that of air, so it is necessary to use force to exhale, so that both inhalation and exhalation can increase the contraction force of respiratory muscles, thus enhancing the function of respiratory system and increasing vital capacity. The average healthy person's vital capacity is 3000-4000 ml, while those who often swim can reach 5000-6000 ml. Influence on human skin: In the swimming process, due to the stimulation of water temperature, the human body wants to ensure sufficient temperature. Skin blood vessels play an important regulatory role. Stimulation of cold water can make skin blood vessels contract and prevent heat from spreading outward. At the same time, the body will intensify the generation of heat, dilate the blood vessels of the skin and improve the blood supply of the blood vessels of the skin, so that long-term exercise can strengthen the blood circulation of the skin. In addition, water is a very soft liquid. Because of the action of water waves, it constantly rubs the human epidermis, so that the skin can be better relaxed and rested. Therefore, people who often take part in swimming exercises have smooth and soft skin. Other functions: As we all know, we live in a sphere filled with three quarters of water, so it is inevitable to deal with water in our life. This is that swimming is not only a sport, but also a rare tool and skill in life. It permeates many fields of our lives, such as water resources development, scientific investigation, flood control and salvage. All this must be backed by skilled swimming skills to ensure life.