<qa>  What is the dose response and duration of action of GSK2190915?This study is intended to determine the dose response and duration of action of GSK2190915 in mild asthmatic adult subjects who experience exercise-induced bronchoconstriction. Subjects will be invited to complete a screening visit, during which time exercise induced bronchoconstriction must be demonstrated, defined as a decrease between 20-40 in FEV1 compared to baseline immediately following exercise challenge. Eligible subjects will complete a randomized, double-blind, five-way crossover study. Subjects will be randomized to a single dose of either 10 mg, 50 mg, 100 mg, 200 mg GSK2190915, or placebo during each treatment period. Each treatment period will last 2 days and will include various assessments following exercise challenge at 2, 9.5, and 24 hours post dose. A minimum 7 day washout between treatment periods will be required. Regardless if a subject completes or prematurely withdraws from the study, a follow up visit will be completed 7-21 days following last dose. 