Exercise-induced bronchoconstriction can be difficult to diagnose clinically given the lack of specific symptoms[2] and frequent misinterpretation as manifestations of vigorous exercise. There are many mimics that present with similar symptoms, such as vocal cord dysfunction, cardiac arrhythmias, cardiomyopathies, and gastroesophageal reflux disease. It is also important to distinguish those who have asthma with exercise worsening, and who consequently will have abnormal testing at rest, from true exercise-induced bronchoconstriction, where there will be normal baseline results.