Yes, research has shown that respiratory muscle training (RMT) improves respiratory muscle strength.
Children and adults suffering from asthma should benefit from using the Breather by being able to clear the airways more efficiently due to increased expiratory muscle strength. RMT also reduces the frequency of asthma attacks, severity and frequency of diurnal and nocturnal symptoms and perception of dyspnea.
Regular RMT by using the Breather should result in reduced need for the use of your rescue bronchodilator.