Comparing Symbicort® As-Needed or Bricanyl As-Needed or Pulmicort® Once Daily + Bricanyl As-Needed in Asthma Patients

1. The primary objective of this study is: * To evaluate the magnitude of the protective effect of the combination of budesonide and formoterol on an as-needed basis compared to the use of terbutaline as-needed on exercise induced bronchoconstriction in adults and adolescents with mild intermittent asthma 2. The secondary objectives of this study are: * To evaluate the magnitude of the protective effect of the combination of budesonide and formoterol as-needed compared to regular once daily use of budesonide plus terbutaline as-needed on exercise induced bronchoconstriction in adults and adolescents with mild intermittent asthma * To evaluate safety of budesonide/formoterol as-needed, terbutaline as-needed and regular use of budesonide + terbutaline as-needed as terms of adverse event