Exercise asthma is asthma that may be triggered or made worse by strenuous exercise. The disease can be seen at any age, but has a higher incidence in male children. It is characterized by chest tightness, wheezing and dyspnea after strenuous exercise lasting up to 5 to 10 minutes or more, and croup may be heard. The symptoms mostly appear within 5-10 minutes after the cessation of exercise, but can also appear during exercise and last for about 0.5-1 hour to gradually resolve, and only a few severe cases can last for 2-3 hours. This type of asthma is related to the type of exercise, time, intensity and the climate at that time. Exercises shorter than 5 minutes, or light exercises such as walking and tai chi, usually do not induce asthma. In the cold and dry season, outdoor walking, climbing, running and playing ball are significantly more likely to trigger asthma than swimming, boating and cycling in summer. This type of asthma can be easily prevented by avoiding strenuous and prolonged exercise, or by using various drugs such as ketotifen and sodium cromoglycate 15 minutes before exercise, and by taking aminophylline and albuterol after the onset of asthma. Different forms of exercise can induce different degrees of asthma. The more strenuous the exercise, the more chances of triggering asthma and the heavier the condition; the longer the duration of an exercise, the more chances of triggering asthma. Race walking, running, mountain climbing, ball games, and parachuting are more likely to cause sports asthma; while sports such as weight lifting, swimming, cycling, and rowing are less likely to cause sports asthma. Light exercise such as walking, tai chi, etc. are less likely to cause asthma; uphill exercise is more likely to cause asthma than downhill exercise. Generally, it takes 5-10 minutes of vigorous exercise to trigger an exercise asthma attack; if the exercise is shorter than 5 minutes, it rarely causes an asthma attack. Asthma symptoms in children often resolve with age, and airway tolerance to exercise may improve, so exercise-induced asthma can often be reduced. Exercise asthma is often familial and there are often multiple asthmatics in the patient’s family. Exercise asthma usually resolves with rest, but it may last for more than an hour and cause a severe asthma attack. If the exercise is repeated within 2 hours after the asthma has stopped, the asthma will not recur, but after a longer period of time, such as 3 hours after the asthma has stopped, the asthma may recur again. How to prevent and control sports asthma? 1. Use preventive medicine before exercise, often 15 minutes before exercise, start inhaling short-acting β2 agonists, such as albuterol aerosol, 200 micrograms each time. Terbutaline aerosol, 250-500 micrograms each time, or sodium cromoglycate aerosol, 20-40 micrograms each time, can effectively prevent and control asthma attacks. 2.Some warm-up activities and preparation for prevention and control before exercise can avoid or reduce asthma attacks. 3.Avoid inhaling dry and cold air. It is advisable to wear a mask when exercising outdoors to help prevent asthma attacks. 4.In case of sports asthma attack, stop exercising immediately and inhale β2 agonist in time, which can effectively relieve the asthma attack. 5.People with a history of sports asthma should pay attention to the intensity, time and items of sports, as well as take reasonable and correct preventive and control measures before sports, etc. This can avoid sudden asthma attacks during sports. In almost all sports, there are many outstanding athletes who suffer from different degrees of asthma. For example, 67 athletes on the U.S. team that participated in the 1984 Los Angeles Olympics suffered from asthma or sports asthma. They were treated with thorough medical care and the application of IOC approved medications, and 47 of these athletes won medals. With careful preventive medication and proper treatment, sports asthma can be completely avoided.