RESUMEN
BACKGROUND: the external nasal dilator (END) has been employed for the purpose of aiding sporting performance. The objective of this study was to evaluate nasal function and cardio-respiratory capacity in healthy adolescent athletes using the END. METHODS: double-blind, crossover clinical trial in which adolescents were evaluated while using the experimental and placebo END during physical exercise. Values for peak nasal inspiratory flow (PNIF), nasal resistance (NR) and maximal oxygen uptake (VO2max) were obtained in randomized order. Additionally, the rating of perceived exertion (RPE) after the cardio-respiratory test was assessed. RESULTS: for the 71 adolescents evaluated, the use of the experimental END, compared to the placebo, produced a significant improvement in values of PNIF (177.4 ± 20.9 L/min and 172.8 ± 20.2 L/min) (p = 0.020), NR (0.24 ± 0.16 and 0.27 ± 0.16) (p = 0.007), VO2max. (39.5 ± 5.2 mL/kg. min-1 and 37.5 ± 5.2 mL/kg. min-1) (p < 0.001) and RPE (6.0 ± 2.2 and 5.5 ± 2.4) (p < 0.001), respectively. CONCLUSION: the END reduced NR, increased PNIF and improved VO2max. In addition, it improved RPE after the maximal cardio-respiratory test. The use of the END can significantly improve nasal function, increase cardio-respiratory capacity and reduce rating of perceived exertion during a maximal test involving adolescent athletes.