Objective. To assess the effects of inspiratory muscle training (IMT) on lung function, inspiratory muscle strength and athletic performance in soccer players.
Method. Participants will be randomized into two groups: experimental and sham . The two groups will perform a protocol of 8 weeks of training (6 days / week) with the PowerBreathe device. The EG will use progressive resistance loads up to 80% of the MIP, while the SG will use the device with a minimum load (20% PImax) during the 8 weeks. All participants will have the following tests before and after the intervention and 3 months after the end of the program: spirometry (FVC, FEV1), PImax, biophotogrammetry, and fit 30/15 test. For the statistical analysis, a 2-factor variance analysis will be performed for repeated measures and Pearson's correlations. The statistical significance will be set with a value of p \<0.05. The effect size will be calculated using the partial eta-square.