● Precautions for swimming in summer
Professor Li Lijun pointed out that summer swimming should pay attention to the following points:
First, don't swim on an empty stomach or after meals.
Many swimmers feel hungry and weak after swimming for a while. Because swimming is a heavy physical activity, limb muscle activity is large, which will consume a lot of energy and calories. If you go swimming on an empty stomach, your blood sugar is too low, and you are prone to hypoglycemia and coma, and even dizziness and collapse may directly drown. Therefore, swimmers should properly supplement some fruits, milk, candy and other foods before swimming, and then swim in the water. Don't swim on an empty stomach, but don't swim after meals. Because swimming in the water immediately after a meal will cause most of the blood to be concentrated in the limbs of the human body, and the amount of blood flowing through the stomach is relatively reduced, which is not conducive to the digestion and absorption of the human body. At the same time, swimming immediately after meals often leads to stomachache and stomach cramps because of the pressure of water on the stomach. Therefore, it is recommended not to swim immediately after meals, and it is best to swim for half an hour after meals.
Second, don't swim after drinking.
Many people who like swimming, after drinking with friends, swim in the water and in the water in order to get cool, regardless of their own safety. In fact, this is an extremely dangerous way. Because after drinking, alcohol will stimulate people's brains, leading to blurred consciousness and easy loss of self-control. If people can't control their behavior after entering the water, it is likely to lead to serious adverse consequences. In addition, after drinking a lot, the amount of glucose stored in the body is consumed, which may lead to hypoglycemia and increase the chance of swimming accidents.
Third, pay attention to prevent pinkeye.
After swimming, some people find their eyes red and swollen. In severe cases, it will cause pain, tears and fear of light. From the etiology, this eye disease is closely related to swimming for too long. Acute hemorrhagic conjunctivitis, also known as "pink eye", is an acute infectious disease. The patient's eye secretions may pollute him and can spread directly or indirectly. At first glance, it is the first disease, feeling burning or sandy friction, then blurred vision, watery secretion, and spread to the other eye a few hours later. The next day, there were different degrees of subconjunctival hemorrhage, eyelid edema, eyeball swelling and pain. Once you get sick, you must go to the hospital to prevent the spread of infection.
In addition, if you are a woman, you should also avoid swimming during menstruation. Such as swimming during menstruation, germs easily enter the uterus, fallopian tubes and other places, causing infection, leading to irregular menstruation, excessive menstruation and prolonged menstruation, affecting health.
Fourth, the activity preparation before swimming.
Preparation before entering the water is extremely important, which can improve the functions of cardiovascular system and respiratory system and accelerate blood circulation and substance metabolism. At the same time, warm-up activities can also improve the working ability of the sports system, increase muscle elasticity and strength, and expand the range of joint activities, which plays a great role in preventing injuries during swimming and avoiding physical discomfort after entering the water. The content and amount of warm-up activities vary according to different swimming postures. The basic principle is to fully exercise all the muscles and joints involved in the activity, and the amount of activity should not be too large. Before entering the water, you need to wipe your body with cold water to adapt your body to the stimulation of cold water.
How to deal with cramps in water?
When swimming, cramps often occur, which are mostly caused by muscle fatigue, excessive tension, water cooling or uncoordinated movements. The most prone to cramps are the calves and thighs, and other parts such as fingers and toes often cramp. Once a cramp occurs, you should first keep your head calm, don't panic, go ashore immediately, dry your body, massage the cramp area and keep warm. In case of calf cramp, you can take a deep breath, float on the water, hold the toe of the cramped leg with the hand opposite the cramped leg and tighten it in the direction of your body. At the same time, the palm of the same side can be pressed on the knee of the cramped limb to help straighten the calf. You can also pinch the center of the calf of the cramped lower limb with your thumb, that is, Chengshan point, and slowly swim back to the shore. If it's a thigh cramp, after taking a deep breath, bend the knee joint with the cramped thigh at right angles to the upper body on the water, then hold the thigh with both hands, firmly stick the body on the thigh and vibrate, then immediately straighten forward and slowly swim back to the shore.
● Understand the common sense of drowning first aid.
In case of drowning, first aid must be given as soon as possible, and the drowning person should be restored to normal gas exchange as soon as possible. After the drowning person is rescued ashore, the dirt and mucus in the mouth and nose should be removed quickly, and water should be poured and artificial respiration should be carried out. When rescuing, it is best to put the drowning person on the natural terrain such as sloping board or slope, with his head down, so as to control the water.
Professor Li Lijun emphasized that American medical experts have come to the conclusion through research and scientific argumentation that physical exercise can prevent cancer. Swimming in summer or winter can make people feel happy, enhance heart and lung function and improve immune function, thus improving human health and quality of life. At the same time, it can also effectively exercise people's will quality. Swimming is not only a competitive sport, but also a fitness project that is most suitable for all kinds of people. According to our living environment and conditions, swimming pools and natural waters are our fitness places. Be sure to remember that safety comes first.
Title map/Che Lijun