Influence of the combination of end-expiratory breath-hold training and inspiratory muscle training on performance in artistic swimmers

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, 15 artistic swimmers (15.7 ± 1.5 years) completed, over 3 weeks, nine training sessions (each involving 32 15-m swim sprints) with EBH complemented with daily IMT at 50% of inspiratory muscle strength (EBH + IMT, <i>n</i> = 8) or the same EBH training with a placebo IMT procedure (EBH, <i>n</i> = 7). Laboratory outcomes and performance measures included inspiratory muscle pressure, peak power output, peak O₂ uptake ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> </mml:math> O_2peak), muscle oxygenation, ventilatory thresholds markers, and a 275 m underwater swim test (UWST). Both groups increased maximal inspiratory muscle strength (∼21%, time effect <i>p</i> < 0.001, Cohen's ES = 0.72). There was a significant interaction for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> </mml:math> O_2peak, which increased more in EBH + IMT than EBH alone (3.1 mL·kg^-1·min^-1, interaction <i>p</i> = 0.036, ES = 0.73). The deoxygenation of the vastus lateralis muscle during the incremental test increased following EBH + IMT only (38%, interaction <i>p</i> = 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 3 weeks led to greater peripheral muscle O₂ extraction, conducive to an increased <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mover><mml:mi>V</mml:mi> <mml:mo>˙</mml:mo></mml:mover> </mml:math> O_2peak gain, but exerted no influence on a more specific swimming/breath-hold performance.