This study explored the effects of combining repeated-sprint training with end-expiratory breath-hold (EBH) and inspiratory muscle training (IMT) on cardiorespiratory fitness and performance in artistic swimming. In a quasi-experimental study, fifteen artistic swimmers (15.7 ± 1.5 years) completed, over 3 weeks, nine training sessions (each involving thirty-two 15-m swim sprints) with EBH complemented with daily IMT at 50% of inspiratory muscle strength (EBH+IMT, n = 8) or the same EBH training with a placebo IMT procedure (EBH, n = 7). Laboratory outcomes and performance measures included inspiratory muscle pressure, peak power output, peak O2 uptake (V̇O₂peak), muscle oxygenation, ventilatory thresholds markers, and a 275-m underwater swim test (UWST). Both groups increased maximal inspiratory muscle strength (~21%, time effect ptextless0.001, Cohen’s ES=0.72). There was a significant interaction for V̇O₂peak, which increased more in EBH+IMT than EBH alone (3.1 ml.kg-1min-1, interaction p=0.036, ES=0.73). The deoxygenation of the vastus lateralis muscle during the incremental test increased following EBH+IMT only (38%, interaction p=0.01). No change occurred in ventilatory threshold markers nor in UWST performance in any groups. These results suggest that combining repeated-sprint training with EBH and daily IMT for three weeks led to greater peripheral muscle O2 extraction, conducive to an increased V̇O₂peak gain, but exerted no influence on a more specific swimming/breath-hold performance