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The influence of an external nasal dilator on breathing in humans during exercise

by Liu, Wan-yeung

Abstract (Summary)
(Uncorrected OCR) Abstract of thesis entitled The Influence of an External Nasal Dilator on Breathing in Humans During Exercise Submitted by LIU, Wan-yeung, Adrian for the degree of Master of Philosophy at the University of Hong Kong in August 2001 The External Nasal Dilator Strip (ENDS) is widely used by many athletes during exercise. It is a butterfly-shaped adhesive bandage that provides an upward pulling force to flare the nostrils and open the nasal passages. There is evidence that the device is effective in relieving certain sleep disorders and snoring by reducing the nasal resistance, thus it has potential benefits associated with a reduction in the nasal work of breathing, increased nasal ventilation and a delay in the onset of oral breathing during exercise. For this study, a special face-mask data-acquisition system was initially developed and tested to ensure it accurately measured oral and nasal gas flows. Following this, 20 male athletes (aged 21.2 ?1.9) ran on a treadmill using a discontinuous incremental exercise protocol. Their heart rate (HR), total inspiration (TI), nasal ventilation (NI), the percentage of ventilation using via the nose (N%) and the mouth (M%), the switching point (SP) from nasal to oronasal breathing, the time constant of the ventilatory responses (TC), and the rating of perceived exertions (RPE) were evaluated using the ENDS under three different conditions (experimental, placebo and control). Although there was an increase in peak inspiratory nasal flow at rest when using the ENDS, no consistent differences were found in HR, TI, NI, N%, M%, SP, TC and RPE across the levels of exercise between the three different conditions. Only during the high intensity exercise was a significant increase in nasal inspiration (NI) found. Furthermore, when compared to previous data on Western subjects, the Chinese runners in this study used a higher N% at moderate and near-maximal stage of exercise, (around 45% and 60% respectively), and also had a higher SP (35 L/min and 42 L/min respectively). These results suggest that when using the ENDS during treadmill running, nasal breathing is not enhanced except possibly a small effect during high intensity exercise, and that the nasal breathing characteristics of Asian and Western subjects appears to be different. It was concluded that, overall, the ENDS did not appear to produce any benefits during most phases of treadmill exercise in Asian male athletes.
Bibliographical Information:

Advisor:

School:The University of Hong Kong

School Location:China - Hong Kong SAR

Source Type:Master's Thesis

Keywords:respiration measurement exercise physiological aspects

ISBN:

Date of Publication:01/01/2002

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