ABSTRACT
BACKGROUND: Numerous studies have shown that the external nasal dilator (END) increases the cross sectional area of the nasal valve, thereby reducing nasal resistance, transnasal inspiratory pressure, stabilizing the lateral nasal vestibule, and preventing its collapse during final inhalation. OBJECTIVES: Our objective was to carry out a systematic review of the literature and meta-analysis on the effects of the END during physical exercise. METHODS: After selecting articles in the PubMed, Cochrane Library and EMBASE databases, 624 studies were identified. However, after applying the inclusion and exclusion criteria, 19 articles were considered eligible for review. RESULTS: Those studies included in the meta-analysis, the maximal oxygen uptake (VO2max.) outcome was assessed in 168 participants in which no statistically significant difference was found, MD (95% CI) = 0.86 [- 0.43, 2.15], p = 0.19, and I2 = 0%. The heart rate (HR) outcome was assessed in 138 participants in which no statistically significant difference was found, MD (95% CI) = 0.02 [- 3.19, 3.22], p = 0.99, and I2 = 0%. The rating of perceived exertion (RPE) outcome was assessed in 92 participants in which no statistically significant difference was found, MD (95% CI) = - 0.12 [- 0.52, 0.28], p = 0.56, and I2 = 27%. CONCLUSIONS: The external nasal dilator strip showed no improvement in VO2max., HR and RPE outcomes in healthy individuals during exercise.
