3-year-old baby coughing after strenuous exercise, may be physiological cough response, may also be variant asthma, can be improved according to the cause, from reducing the amount of activity and medication and so on. 1. normal physiological cough response: 3-year-old baby will cough after strenuous exercise, may be due to strenuous exercise will stimulate the cough response, which leads to coughing symptoms aggravated, generally in the appropriate reduction in the amount of activity, the baby’s symptoms will slowly disappear. 2. variant asthma: variant asthma may cause the baby airway sensitivity is very high, in the encounter stimulation when the cough will increase, so need to give the nebulized bronchodilator for relief, such as terbutaline sulfate nebulization. The above drugs are recommended to be taken under the guidance of a doctor, not to be used on their own. 3 year old baby coughing with strenuous exercise, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.