Eight mild asthmatic ( age = 26 yr ; VO2peak = 49 mLkgmin ) and nine nonasthmatic ( age = 30 yr ; VO2peak = 46 mLkgmin ) adults performed constant workrate cycling exercise to exhaustion after four separate interventions : 1 ) a control trial ( CON ) ; 2 ) inhalation of fast-acting 2-agonist ( BD ) ; 3 ) eucapnic voluntary hyperpnea challenge ( BC ) ; and 4 ) sham to the hyperpnea ( SHAM ) .