IMT

Objective To evaluate the acute effect of four inspiratory warm-up intensities (15%, 40%, 60%, and 80% of maximal inspiratory pressure \[MIP\]) on 100 m freestyle performance, and to analyze their impact on heart rate, blood lactate concentration, perceived exertion, and dyspnea in trained swimmers. Methods A randomized, crossover, double-blind experimental study was conducted. Participants were swimmers aged ≥18 years, with no respiratory or musculoskeletal pathology. Each participant completed, in sessions separated by at least three days, an inspiratory muscle warm-up consisting of 30 breaths against resistive loads set at 15%, 40%, 60%, and 80% of their MIP, previously determined using standardized procedures. Following each intervention, participants performed a maximal 100 m freestyle test. The following variables were recorded: Swimming time Heart rate (during and post-exercise) Post-exercise capillary blood lactate concentration Rating of perceived exertion (Borg scale) Dyspnea (Dyspnea-12) Conclusions This study will help identify the optimal inspiratory warm-up intensity to enhance swimming performance.