Exercise changes volatiles in exhaled breath assessed by an electronic nose

Area of Science:

• Physiology
• Biochemistry
• Analytical Chemistry

Background:

• Metabolic changes during exercise can be monitored via exhaled volatiles.
• The impact of physical exertion on the spectrum of exhaled gases and its relation to exhaled breath condensate (EBC) pH remains largely uninvestigated.

Purpose of the Study:

• To investigate if physical exercise alters the pattern of volatile organic compounds (VOCs) in exhaled breath.
• To determine if changes in exhaled VOCs correlate with alterations in EBC pH following exercise.

Main Methods:

• Ten healthy subjects underwent a 6-minute running test.
• Exhaled breath samples were collected pre- and post-exercise (0, 15, 30, 60 min) for volatile pattern analysis using an electronic nose.
• EBC pH was measured at 5.33 kPa CO2.

Main Results:

• Both exhaled breath smellprints (VOC patterns) and EBC pH were significantly altered post-exercise (p=0.04 and p=0.01, respectively).
• Differences in smellprints and pH were observed at 15, 30, and 60 minutes post-exercise compared to pre-exercise values.
• A significant negative correlation was found between the volatile pattern and EBC pH (p=0.01, r=-0.34).

Conclusions:

• Physical exercise induces significant changes in the pattern of exhaled volatile organic compounds.
• Exercise also leads to an increase in the pH of exhaled breath.
• Alterations in exhaled volatiles are likely responsible for the observed increase in EBC pH post-exercise.