A randomized, double-blind, active controlled, multicenter, parallel treatment, 3x3 dose level crossover study evaluating the dose response of levalbuterol in pediatric subjects between the ages of 6 and 11, inclusive with exercise induced bronchoconstriction. This study was previously posted by Sepracor Inc. In October 2009, Sepracor Inc. was acquired by Dainippon Sumitomo Pharma., and in October 2010, Sepracor Inc's name was changed to Sunovion Pharmaceuticals Inc.