Background: Asthma is a major health condition in Iran. This randomized clinical trial was aimed for the comparison of the effects of two exercise protocols (aerobic and aerobic-strength) on the pulmonary indices and quality of life of asthmatic patients.

Methods: The study was conducted in pulmonary ward of Dr Shariati Hospital in Tehran, and Research Center of Exercise Medicine of Tehran in 2009. Fifty six asthmatic patients were selected and after two weeks of education, their spirometric parameters were recorded and the St George's respiratory questionnaire was completed. Then patients were randomly assigned to two groups of A and B. For ten weeks group A did the aerobic-strength exercises and group B did only the aerobic ones at home. At the end, again their spirometric parameters were recorded and the questionnaire was completed. Finally 42 patients completed the study.

Results: After the intervention, FEV1 and FVC but not FEV1/FVC increased in group A. There were no changes in these parameters in group B. In addition, post-intervention FEV1 and FVC were significantly higher in group A than group B. All scores of St George's respiratory questionnaire were significantly improved in both groups but they were not different between them.

Conclusions: Our findings showed that regular aerobic exercises, individually or concomitant with strength exercises, could improve vital signs and quality of life of mild to moderate asthmatic patients. However, only aerobic exercises with strength ones improve spirometric parameters. Therefore, a combination of both aerobic and strength exercises could be considered in treatment protocols of asthmatic patients.