Inclusion Criteria

• Subjects were males or females and 18 years of age or older at the time of consent.
• Female subjects considered not of childbearing potential were either surgically sterile or greater than one-year postmenopausal, defined as a complete cessation of menstruation for at least one year.
• Female subjects of child-bearing potential had a negative urine pregnancy test at screening.
• Female subjects of child-bearing potential agreed to use an acceptable method of birth control throughout the study.
• Subjects were in good health and were not suffering from any chronic condition that might affect their respiratory or cardiac function (including cardiac arrhythmias).
• Subjects had a documented diagnosis of exercise-induced bronchospasm for a minimum of 6 months prior to study start.
• Subjects had stable baseline asthma and had been using a beta2-adrenergic agonist, and/or anti-asthma anti-inflammatory medication, and/or over-the-counter asthma medication for at least 6 months prior to study start.

Exclusion Criteria

• Subjects with currently diagnosed life-threatening asthma defined as a history of: asthma episodes requiring intubation, associated hypercapnia, respiratory arrest, or hypoxic seizures within 12 months prior to study start.
• Subjects with a history of hospitalization for asthma within 4 weeks prior to study start, or who were scheduled for in-patient hospitalization, including elective surgery, during the course of the trial.
• Subjects with a documented history of bronchopulmonary aspergillosis or any form of allergic alveolitis.
• Subjects who suffered from a clinically significant upper or lower respiratory tract infection in the 3 weeks prior to study start.
• Subjects with any clinically significant unstable medical abnormality, chronic disease (other than asthma), or history of a clinically significant abnormality of the cardiovascular, gastrointestinal, respiratory, hepatic, renal, endocrine, or central nervous systems that was not currently well controlled by medication or that may have interfered with the successful completion of the protocol.
• Subjects with a history of cancer (exception: basal-cell carcinoma in remission for a minimum of 5 years).
• Subjects with a known sensitivity to levalbuterol, racemic albuterol, or any of the excipients contained in any of these formulations.
• Subjects using any prescription drug with which levalbuterol tartrate administration is contraindicated.
• Subjects with a history of substance abuse or drug abuse within 12 months preceding study start.
• Subjects who participated in an investigational drug study within 30 days prior to study start, or who were currently participating in another clinical trial.
• Subjects with a greater than 10-pack-year history of cigarette smoking or use of any tobacco products within 6 months of study start.
• Subject was a staff member or relative of a staff member.
• Subjects with unstable asthma, or had a change in asthma therapy, or a visit to the emergency department or hospital for worsening asthma within 4 weeks of study start.