1.Definition A breathing training method that applies resistance during expiration. To appropriately increase airway resistance to reduce or prevent premature closure of small airways at the lesion site during expiration, so as to improve ventilation and air exchange and reduce the amount of residual air in the lungs. 2. Indications and contraindications (1) Indications: chronic obstructive pulmonary disease (chronic bronchitis, emphysema, asthma and cystic fibrosis), spinal cord injury, etc. (2) Contraindications: unstable clinical condition, uncontrolled infection, respiratory failure, other clinical conditions that can lead to deterioration during training, severe cognitive deficits and mental illnesses that affect memory and compliance. 3.Equipment and appliances No equipment is required. 4.Operating methods and procedures Lip retraction, bottle blowing and articulatory breathing can be used. Here, take lip reduction and exhalation as an example, introduce the operation method and steps: when training, put the patient in a comfortable and relaxed position, shut up and inhale deeply through the nose, and when exhaling, close the mouth in a whistle-like manner, so that the gas slowly passes through the narrowed mouth shape, and the ratio of inhalation to exhalation is 1:2; when exhaling, the size of the lip reduction is adjusted by the patient’s own choice, not too big or too small; usually there are many patients with dyspnea who can improve shortness of breath with this method. In most cases, after the patient has mastered abdominal breathing, the patient can stop using the lip retraction method of exhalation. 5. Precautions (1) The training environment should be quiet to avoid excessive disturbance to the patient. (2) Let the patient wear loose clothing and adopt a comfortable and relaxed position. (3) Avoid holding the breath and excessively slowing down the breathing rate to avoid inducing respiratory acidosis. (4) The principles of rehabilitation for pulmonary diseases are persistent, gradual and individualized. (5) Gradually increase the amount of exercise, according to the ability, in order not to cause obvious fatigue, otherwise may induce or aggravate the onset of lung disease. (6) In addition to respiratory exercises, patients can also carry out moderate physical training, such as walking, climbing steps, tai chi, etc., in order to enhance physical fitness, reduce the number of attacks and reduce the degree of attacks. In addition, patients should also pay attention to make corresponding adjustments in nutrition, psychological status and lifestyle habits (such as quitting smoking).