Exercise asthma, also known as exercise-induced asthma, is asthma that results from bronchospasm after a certain amount of exercise, so its attacks are acute, brief, and most resolve on their own. Exercise asthma can occur in patients of any age and gender, but is much more common in children than in adults, and more common in men than in women. The incidence of exercise-induced asthma varies among reports due to differences in relative humidity and temperature of sports venues, different sports programs and assessment criteria, and differences in post-exercise observation time. Hyperventilation during exercise causes a large amount of heat and water loss in the airway, which leads to airway smooth muscle spasm through a series of neurohumoral mechanisms and causes asthma attacks. Exercise asthma does not mean that exercise can cause asthma, in fact, brief exercise not only does not cause asthma, but also can excite breathing, so that the bronchial tubes have a brief expansion, lung ventilation function improved, and then with the extension of exercise time, the intensity increases, the bronchial tubes turn to contraction, causing asthma. Generally speaking, exercises shorter than 5 minutes rarely cause asthma attacks. In most patients, chest tightness, shortness of breath, dyspnea and wheezing occur 6D10 minutes after the start of vigorous exercise or 2D10 minutes after the cessation of exercise, and obvious croup can be heard in the lungs. The above symptoms gradually resolve within 0.5D1 hours. In a few severe patients, they may last for 2D3 hours. In rare patients, the above asthma symptoms appear 4D13 hours after exercise and are referred to as exercise-induced delayed asthma response. The occurrence of exercise-induced asthma is related to the type of exercise, its stressfulness, and the prevailing climate. In the cold season, walking, running, climbing and playing ball games outdoors are likely to induce exercise asthma, while in summer, swimming, weight lifting and rowing are less likely to cause exercise asthma. Light exercises such as walking and tai chi are less likely to cause locomotor asthma, while vigorous exercises are more likely to cause locomotor asthma. Patients with clinical suspicion of exercise-induced asthma should have pulmonary function tests before and after exercise to determine the presence of exercise-induced asthma based on the changes in pulmonary function before and after exercise, a method also known as exercise provocation test. Commonly used exercise modalities are running, bicycle power test and flatbed exercise test. Mild exercise asthma is diagnosed if there is a 20D40% decrease in the first second of forceful expiratory volume after exercise, moderate exercise asthma is diagnosed if there is a 40D65% decrease, and severe exercise asthma is diagnosed if there is a decrease of 65% or more. Patients with severe cardiopulmonary or other diseases affecting exercise cannot perform exercise tests, and appropriate resuscitation measures should be available during the test and should be performed under the guidance of medical professionals. Inhalation of beta agonist and/or sodium cromoglycate 15 minutes before exercise can effectively prevent the occurrence of exercise asthma in patients with exercise asthma. Pre-exercise warm-up activities, wearing a mask during the cold season and avoiding outdoor exercise to avoid inhaling dry, cold air can also help prevent exercise asthma. People with asthma should not be discouraged from participating in sports because of exercise-related asthma. In fact, there are many great athletes in almost all sports who are asthmatic. The athlete who won four solo gold medals in swimming at the Los Angeles Olympics was an asthmatic.