Beta2-agonists, both short-acting (SABA) and long-acting (LABA), when administered in a single dose, may be effective in preventing exercise-induced asthma. Longer-term administration of inhaled beta2-agonists appears to induce tolerance and lack sufficient safety data Beta2-Agonists for Exercise-Induced Asthma.
British guideline on the management of asthma. British Thoracic Society (BTS) / Scottish Intercollegiate Guidelines Network (SIGN). Guideline No. 141, October 2014 http://www.sign.ac.uk/pdf/SIGN141.pdf