The effect of eight weeks of respiratory muscle training on respiratory indices and the performance in adolescent male swimmers: A randomized control trial

Abstract

Abstract Background: Improvement in the strength of respiratory muscles following inspiratory muscle training (IMT) has been seen in the majority types of athletes. Still, there are contradictory results of its effect on the athletes' performance, especially swimmers. The study aimed to evaluate the effect of the IMT program along with other routine exercises in increasing the performance of adolescent swimmers. Methods: The present study was conducted on professional swimmers who were divided into intervention and control groups. Both groups had identical routine training in their team's camp. The intervention group was prescribed eight weeks of progressive IMT with a starting strength of 30% MIP daily, twice a day for three sets of 15 repetitions per set with a threshold resistance device. The control group trained with 15% maximum inspiratory pressure (MIP) constantly. Spirometric indices, MIP, and the swimming fifty meters' personal best time (50 meters PBT) were assessed before and after the trial. Results: A total of 20 adolescent male swimmers (mean age 13.05(2.01) years; body mass index 19.85(2.31) kg/m2) were included in the study. The strength of inspiratory muscles, forced expiratory volume in the first second (FEV1) and 50meters PBT were significantly improved in the intervention group (p<0.005), however, forced vital capacity (FVC) and FEV1/EVC had no significant improvement compared to the control group (p>0.005). Conclusion: Findings indicate the importance of using IMT in the process of swimming education and could help coaches provide swimmers with more effective IMT protocols to maximize the benefits of training.