What is the health value of swimming?
1, improving 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. At rest, diastolic blood pressure increases and systolic blood pressure decreases, so the blood pressure value becomes more favorable. The elasticity of blood vessels has also improved.
2. Improving vital capacity mainly depends on the lungs. The strength of lung function is determined by the strength of respiratory muscle function. Exercise is one of the effective means to improve and increase vital capacity. According to the measurement, when swimming, people's chest is under the pressure of 12- 15 kg. Cold water stimulates muscle contraction, making it difficult to breathe, forcing people to breathe hard, increasing the depth of breathing, and making the amount of oxygen inhaled meet the needs of the body.
3. Improve the function of the respiratory system. One of the main characteristics of water is that it is difficult to compress. Because the density of water is more than 800 times higher than that of air, the pressure on people in water is far greater than that in air. This is also the reason why beginners have difficulty breathing in the water. As the pressure in the chest and abdominal cavity increases in water, it forces the respiratory muscles to breathe with greater strength. Therefore, regular swimming can increase the strength of respiratory muscles and improve the function of respiratory system. The most obvious example is the value of vital capacity. A swimmer's vital capacity can reach 4000 to 6000 ml, or even 7000 ml, while the average person only has 3000 to 4000 ml.
4. Improving the ability of muscle system Swimming is a whole-body exercise, which can mobilize more muscle groups to participate in metabolism and energy supply than other sports. Although swimming can't build thick and bulging muscles, it can improve the strength and coordination of many muscles, especially the muscles of trunk, shoulder straps and upper limbs. Because swimming in water needs to overcome great resistance, and swimming is a periodic exercise, long-term exercise can improve muscle strength, speed, endurance and joint flexibility.
5, strengthen skin blood circulation
In the process of swimming, due to the stimulation of water temperature, the body in order to ensure adequate 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.
6, enhance resistance
The water temperature in the swimming pool is often 26 to 28 degrees, so soaking in water dissipates heat quickly and consumes a lot of energy. In order to supplement the heat emitted by the body as soon as possible and meet the needs of cold and heat balance, the nervous system reacts quickly, accelerating the metabolism of the human body, enhancing the adaptability of the human body to the outside world and resisting the cold. People who often take part in winter swimming are not easy to catch a cold because of the improvement of body temperature regulation function, and can also improve the endocrine function of human body and increase the function of pituitary gland, thus improving the resistance and immunity to diseases.
Step 7 lose weight
When swimming, the body is directly immersed in water, which not only has great resistance, but also has very good thermal conductivity and fast heat dissipation, so it consumes more heat. Like a boiled egg, the cooling rate in air is far less than that in cold water. Experiments show that the heat consumed by a person swimming in a standard swimming pool for 20 minutes is equivalent to swimming on land at the same speed 1 hour, and staying in water with 100 minutes is as high as 100 kcal, which is equivalent to being in air with the same temperature. In addition, swimming diet can avoid sports injuries of lower limbs and waist.
8. bodybuilding
When swimming, people usually use the buoyancy of water to lie prone or supine in the water, so that the whole body can be relaxed and stretched, so that the body can develop comprehensively, symmetrically and harmoniously, and the muscle lines can be smooth. Exercise in water reduces the impact of the ground on bones, reduces the probability of bone aging, and the joints are not easy to deform. The resistance of water can increase people's exercise intensity, but this kind of intensity is very soft, which is different from the equipment training on land. The training intensity is easily controlled within the aerobic range, so that stiff muscle blocks will not grow and the whole body lines will be smooth and beautiful.
Swimming taboo
1, avoid long-term contact with swimming. Long-term exposure can cause sunburn or acute dermatitis, also known as sunburn. In order to prevent sunburn, it is best to use an umbrella to shade the sun after landing, or rest in a cool place, or use a bath towel to protect the skin, or apply sunscreen to exposed parts of the body.
2. Avoid not doing warm-up activities, that is, the swimming water temperature is usually lower than the body temperature. Therefore, warm-up activities must be done before entering the water, otherwise it will easily lead to physical discomfort.
3. Avoid eating immediately after swimming. It is advisable to take a break before eating, otherwise it will suddenly increase the burden on the gastrointestinal tract and easily cause gastrointestinal diseases over time.
4, avoid swimming for too long, the skin generally has three reaction periods to cold stimulation. The first stage: after entering the water, stimulated by cold, the skin blood vessels contract and the skin color is pale. The second stage: after staying in the water for a certain period of time, the blood flow on the body surface expands, the skin turns from pale to reddish, and the skin turns from cold to warm. The third stage: the stay time is too long, the heat dissipation of body temperature is greater than fever, and the skin has goose bumps and chills. This is a taboo period for summer outing, so leave the water in time. Generally, the swimming time should not exceed 1.5~2 hours.
5. Avoid swimming in unfamiliar waters. When swimming in natural waters, avoid rushing into the water. Under complicated circumstances, it is not advisable to swim around the water surface and underwater to avoid accidents.
6, avoid swimming on an empty stomach Many people who love swimming have a feeling that after swimming ashore, they will feel hungry and weak. This is because swimming is a heavy physical exercise, with a large amount of muscle activity in the limbs, which will consume a lot of energy and heat in the human body. If we go swimming on an empty stomach, it will cause hypoglycemia, especially for diabetics, and the risk of hypoglycemia coma is greater. If swimmers are hungry, their blood sugar is too low and they consume a lot of energy, they are particularly prone to muscle trembling, dizziness, collapse, coma and even direct drowning. Therefore, swimmers should properly supplement some fruits, milk, candy and other foods before swimming, and then swim in the water.
7. Girls who avoid swimming during the physiological period must avoid swimming in the water at this time, because during menstruation, germs can easily enter the uterus, fallopian tubes and other places through water, causing infection, leading to irregular menstruation, excessive menstruation or prolonged menstruation.
Precautions for swimming
1. You must swim under the guidance of your parents (guardians). Swimming alone is the most prone to problems. If your partner is not a parent (adult), it is difficult to ensure that you can handle it properly in case of danger.
People who are sick should not go swimming. Patients with chronic diseases such as otitis media, heart disease, dermatosis, liver and kidney diseases, hypertension, epilepsy and pinkeye, as well as those with colds, fever, mental fatigue and physical weakness, cannot swim.
3. After taking part in strong physical labor or strenuous exercise, you can't jump into the water to swim immediately, especially when you are sweating or fever. Otherwise, it is easy to cause cramps and colds.
4, cold, illness, physical discomfort or weakness, after meals, fasting, drinking alcohol is not suitable for swimming.
5. Polluted (poor water quality) rivers, reservoirs, places with rapids, the intersection of two rivers and lakes with gaps are not suitable for swimming.
Who are not suitable for swimming?
1. People suffering from severe heart disease, hypertension and mental disorders are prone to sudden fainting or unconsciousness when entering the water.
2. People who are prone to convulsions due to epilepsy should not swim in case of sudden onset and loss of swimming skills.
3. Patients with infectious skin diseases such as viral hepatitis, bacillary dysentery, pinkeye, sexually transmitted diseases and tinea corporis should not take part in swimming to prevent the spread of infectious diseases.
4. Deaf-mute people should not take part in swimming, because the organs that regulate the balance in the middle ear of deaf-mute people will also be damaged, thus weakening the balance ability of the body, and often drowning accidents occur because of losing balance. After the perforation of the tympanic membrane into the water, the water will enter the middle ear cavity through the perforation of the tympanic membrane and cause acute otitis media, so it is not suitable for swimming. People with suppurative otitis media can't swim, because pus with bacteria in the middle ear cavity may flow into the swimming pool water, polluting other swimmers and making them have an acute attack of chronic suppurative otitis media.
5. Women can't swim during menstruation, pregnant women, within two months after delivery, within one month after induced abortion or tubal ligation, and within half a month after Sheung Wan.
6. People with tuberculosis, emphysema, nephritis, trachoma, acute conjunctivitis, corneal ulcer, high myopia and acute sinusitis should not swim; People and alcoholics should not swim immediately after strenuous activities.