Short bursts of activity are much better than endurance sports
Weight training and running sprints are much better than spending an hour on the treadmill
Switch it up and experiment with different types of sport
Call it quits
If you have an airway infection
If for any reason your asthma kicks in during exercise
If Smart Peak Flow tells you you are in the yellow zone
Talk to your doctor if you are one of the few people with exercise induced asthma, where more than 10 minutes of strenuous exercise is the trigger. The right medication should allow you to do sports again.