Editor's Note: Jianlibao, together with the Scientific Research Institute of the State Sports General Administration, provides correct and effective sports knowledge and suggestions to avoid mass sports injuries and achieve effective fitness effects. Swimming is a very good fitness method, which is widely used because of its good fitness effect on cardiopulmonary function and the buoyancy of water to prevent sports injuries. But there are also some inappropriate situations, mainly from the following aspects: First, people who are not suitable for swimming. Mainly refers to patients with heart disease, emphysema, epilepsy, deafness and dizziness, swimming will increase the burden on the heart. Patients with heart disease should follow the doctor's advice if they want to engage in swimming. For patients with pulmonary insufficiency such as emphysema (chronic bronchitis), swimming will also increase the risk, because the pressure of water will increase the pressure on the chest and abdomen, and the expansion of the chest and the lifting of the diaphragm may increase the difficulty, leading to aggravated pulmonary dysfunction, difficulty in breathing, lack of oxygen and dizziness. For epileptic patients, it is very dangerous if they have seizures while swimming, and they will have convulsions, coma and lose the ability to save themselves and call for help. Patients with inner ear diseases should not swim because the inner ear is an important balancer palace of the human body. Water sports require high balance ability, and poor balance ability is very dangerous. In addition, patients with chronic suppurative otitis media should not swim. When swimming, water will be poured into the ear canal, and the water will bring bacteria into the ear canal, which will lead to the aggravation of the disease. Some people are very sensitive to the cold and even allergic. When swimming is stimulated by cold, they will feel dizzy, flustered, short of breath and even coma. The second is a special period that is not suitable for swimming. Acute stage of diseases such as cold and fever, menstrual period of women, etc. People suffering from infectious diseases such as tinea corporis, tinea pedis and trachoma, and women suffering from fungal vaginitis and trichomonal vaginitis. When swimming, bacteria will spread into the water and infect others. Third, drinking is not suitable for swimming. It is not advisable for some people to go swimming after eating. After drinking, the cerebral cortex is in a state of inhibition, which makes people's movements unbalanced and prone to danger when swimming; Moreover, after drinking, the body temperature rises, and cold and heat are easy to cause diseases such as colds; Swimming after a full stomach will lead to insufficient blood supply to the gastrointestinal tract and decreased secretion of digestive juice. Over time, it will cause diseases such as indigestion and stomach pain. (Joint contribution by Sports Science Research Institute of State Sports General Administration and Guangdong Jianlibao Company)