Indirect airway hyperresponsiveness (AHR) is a physiologic feature that is highly specific for asthma and provides a unique insight into the mechanisms responsible for airway dysfunction. Individuals at risk for indirect AHR have distinct alterations in their airways that are further dysregulated following exposure to specific stimuli and promote bronchoconstriction. Dry air exercise challenge and inhaled mannitol challenge are tests for indirect AHR, which can be used by clinicians to characterize exercise-related symptoms concerning for exercise-induced bronchoconstriction, evaluate individuals presenting with asthma-like symptoms, and to titrate asthma-directed therapies.