When exposed to air pollution, the asthma symptoms are aggravated and lung function is impaired. Due to high breathing rates and volumes, physically active individuals are at particular risk of lung health impairment due to the high breathing rates and volumes. Greater doses of air pollutants reach deeper areas in the lungs where they can trigger asthma-symptoms. When treating these symptoms with inhaled beta-2-agonists the airways widen even more, allowing the air pollutants to reach even deeper areas of the lung. With this study the investigators investigate how inhaled beta-2-agonists affect athletic capacity and lung health in physically active asthmatics.