What is a test that uses spirometry before and after strenuous activity such as walking on a treadmill or riding a stationary bike?

The test you're referring to is known as a "bronchodilator responsiveness test" or "exercise-induced bronchospasm test." It involves measuring lung function using spirometry before and after the patient engages in strenuous activity, like walking on a treadmill or riding a stationary bike. This test helps assess how exercise impacts airway function, particularly in individuals with Asthma or other respiratory conditions, by observing changes in lung capacity and airflow. It can identify exercise-induced bronchoconstriction or assess the effectiveness of bronchodilators.