My son only gets asthma when he plays sport, he has a puffer which works but doesn't solve the issue. would you recommend chinese medicine?

No: your son needs evaluation, it sounds that it isn't only Exercise Induced Asthma, more strings are attached. He may very well need a controller medicine in addition to the rescue puffer that he uses before exercise or only as needed, or he may have a nose/sinus disease, etc..kindly see an allergist/asthma specialist, check aaaai.org or acaai.org for an allergist/immunologist in your area, goodluck

Exercise Asthma: I was surprised to learn that up to 80% of children with asthma have exercise induced asthma caused by reversible airway constriction triggered by exertion and strong emotion. Use of a bronchodilator prior to exercise is the accepted approach to prevention.