Effect of respiratory muscle training on pulmonary function and aerobic endurance in soccer players.

BACKGROUND: Few studies investigated the effects of the respiratory muscle training (RMT) in soccer although exhaustive high intensity exercise is known to lead to muscle fatigue in respiratory muscles. The purpose of this study was to investigate the effect of RMT on pulmonary function and aerobic endurance in soccer players. METHODS: Eighteen male soccer players (mean age 22.2±1.4 years) participated in this study. Participants were assigned randomly to either an RMT or a control (CON) group. The RMT group performed a 15-minute endurance training of respiratory muscles twice a week for 5 weeks. The CON group did not receive RMT during this period. All participants were evaluated for aerobic endurance using 20-meter shuttle run test (20-MST), pulmonary function, maximal inspiratory mouth pressure (MIP), and maximal expiratory mouth pressure (MEP) using spirometry. RESULTS: There was a significant improvement in RMT group (14%) as compared to CON group (4%) in MIP measurement (P=0.04). No significant differences were observed in forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), maximum voluntary ventilation (MVV), and MEP after a five week of RMT (P>0.05). Similarly, there was no difference in 20-MST in the RMT group compared to CON group (P>0.05). CONCLUSIONS: We concluded that a five week of RMT increased MIP, but FVC, FEV1, MVV, MEP and aerobic endurance did not improve in soccer players. The RMT in addition to soccer training may improve MIP but not the tolerance to high intensity exercise.