THE EFFECTS OF EXERCISE INTENSITY ON RESPIRATORY PATTERNS DURING OZONE EXPOSURE

• Grant number: 23/17947-2
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: June 01, 2024
• End date: May 31, 2025
• Field of knowledge: Health Sciences - Physical Education
• Principal Investigator: Rômulo Cássio de Moraes Bertuzzi
• Grantee: André Casanova Silveira
• Supervisor: Michael Stephen Koehle
• Host Institution: Escola de Educação Física e Esporte (EEFE). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of British Columbia, Vancouver (UBC), Canada
• Associated to the scholarship: 22/04960-8 - Effects of air pollution on BDNF levels, inflammatory markers, sympathetic nervous activity, cognitive performance and sports performance in cyclists chronically exposed to different levels of pollutants, BP.PD

Abstract

Amongst the main air pollutants, ozone (O3) has been documented as a respiratory irritant. When inhaled, O3 can damage the lungs causing mainly chest pain, coughing, shortness of breath and throat irritation. It seems that when it is inhaled in high doses over the long-term, it is highly toxic for the pulmonary system. In particular during high intensity exercise, there is a change in the respiratory pattern due to a transition from nasal breathing to mouth breathing. This occurs because of the increased demand for oxygen by the exercised muscles. As a possible consequence, in polluted environments, it leads to an increased dose of pollutants entering the airway and reaching the lungs. However, there is no available data about whether oral-only breathing leads to greater ozone effects than oronasal breathing during exercise bouts in different intensities. METHODS: 12 participants will visit the laboratory on five occasions. On the first visit, they will undertake a maximal cycling exercise test to determine the maximal oxygen consumption. On the second to five visit we will use a 2 X 4 design, with two conditions (ozone and room air) and four exercise exposures (low-intensity oronasal, low-intensity oral-only, high-intensity oral-only and high intensity oronasal). The individual will use a facemask instead of a mouthpiece, and then selectively occlude the nares (with a clip) in order to force mouth ventilation. With such a design we will be able to partition out the intensity-only effect (by comparing oronasal bouts of different intensities) from the oral vs oronasal effect. Hypothesis: This study was designed to test the hypothesis that during an exercise exposed to O3 oral-only breathing leads to greater harmful effects than oronasal breathing. This way, it is expected that the deleterious effects of O3 exposure could be minimized handling the exercise intensity and the respiratory patterns.