The External Nasal Dilator: Style over Function?

Abstract

This study examined the effects of an external nasal dilator (END) on sedentary and aerobically trained women using the blood lactate threshold as a measure of aerobic performance. Three groups of women (sedentary, pre-season, in-season) participated in the study: nine sedentary college students (age 19 +/- 1.0 y), eight pre-season college athletes (age 20 +/- 2.3 y), and six in-season college rowers (age 20 +/- 1.7 y). A two-way repeated-measures design was used with subjects in each group being exposed to both conditions (with END and without END). The first two groups performed two incremental exercise tests in random order on a cycle ergometer, and the third group performed the tests on a rowing ergometer. Participants in each group wore an END strip for only one of the tests. Venous blood was collected at rest, during the final 30 seconds of each stage, and 1 and 3 minutes into the recovery period for the determination of blood lactate concentration and identification of the blood lactate threshold. No significant differences (P = 0.05) were found in blood lactate concentration at the lactate threshold between conditions for either group (sedentary: with END 2.51 +/- 1.18 mmol x L(-1), without END 2.56 +/- 0.84 mmol x L(-1); pre-season: with END 2.93 +/- 0.97 mmol x L(-1), without END 2.81 +/- 1.15 mmol x L(-1); and in-season: with END 3.93 +/- 0.50 mmol x L(-1), without END 3.49 +/- 0.387 mmol x L(-1)). We conclude that (a) the END did not improve the lactate threshold in either sedentary or trained college-age women, and (b) the END did not result in lower blood lactate levels during moderate to high-intensity exercise in the three groups examined in this study.

Distinguishing science from pseudoscience in commercial respiratory interventions: an evidence-based guide for health and exercise professionals

“…Other studies, using esophageal balloon catheters, showed no effect of ENDs on inspiratory elastic work, inspiratory resistive work, or expiratory resistive work during submaximal or maximal exercise (O'Kroy et al 2001). There was also no effect of ENDs on recovery of VO 2 , VE , or HR after exercise when compared to a placebo or a no-intervention control (Thomas et al 2001), and no effect of ENDs on blood lactate responses after exercise in sedentary or endurance trained women (Boggs et al 2008). Thus, nasal dilators appear to have no meaningful influence on physiological variables during or after exercise.…”

Effects of oxymetazoline on nasal flow and maximum aerobic exercise performance in patients with inferior turbinate hypertrophy

“…21 Boogs et al found no differences in the lactate threshold between three groups of female university students with different levels of training who underwent two incremental exercise tests with and without a nasal dilator. 23 The decrease in nasal airway resistance and improved breathing during exercise have been related with improved sports performance. 20,21 However, as with Nunes et al 17 and O'Kroy et al, 18 we found no differences in PRE between different stages of exercise testing.…”

External nasal dilators: definition, background, and current uses

“…Numerous studies showed that there was no performance improvement with the END. 9 – 11 , 13 , 18 – 23…”

“…The data indicate that during moderate- and high-intensity aerobic exercise, an END does not cause improvement in the blood lactate threshold. 9 …”