Submitted on August 5, 2002
Accepted on April 7, 2003
NASAL CONTRIBUTION TO BREATHING WITH EXERCISE: EFFECT OF RACE AND GENDER
William D Bennett1*, Kirby L Zeman1, and Annie M Jarabek2
1 Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
2 National Center for Environmental Assessment, US Environmental Protection Agency, Research Triangle Park, NC, USA
* To whom correspondence should be addressed. E-mail: William_Bennett{at}med.unc.edu.
Because the nose acts as a filter to prevent penetration of toxic particles and gases to the lower respiratory tract, the route of breathing, oral vs. nasal, - may be an important determinant of toxicant dose to the lungs. Using respiratory inductance plethysmography and a nasal mask fitted with flow meter, we measured the nasal contribution to breathing at rest and during exercise (to 60% max workload) in healthy young adults (Male/Female = 11/11 and Caucasian/African-American = 11/11). We found that the nasal contribution to breathing is less during submaximal exercise in the Caucasians vs. African-Americans (e.g. at 60% max workload, mean nasal/total ventilation = 0.40 +/- 0.21 and 0.65 +/- 0.24 respectively, P < 0.05). This difference is likely due to the African-Americans ability to achieve higher maximal inspiratory flows through their nose than the Caucasians. Males also had a lesser nasal contribution to breathing during exercise as compared to females. This is likely due to greater minute ventilations at any given %max workload in males vs. females.
