The Impact of a Graded Maximal Exercise Protocol on Exhaled Volatile Organic Compounds: A Pilot Study

Abstract

Exhaled volatile organic compounds (VOCs) are of interest due to their minimally invasive sampling procedure. Previous studies have investigated the impact of exercise, with evidence suggesting that breath VOCs reflect exercise-induced metabolic activity. However, these studies have yet to investigate the impact of maximal exercise to exhaustion on breath VOCs, which was the main aim of this study. Two-litre breath samples were collected onto thermal desorption tubes using a portable breath collection unit. Samples were collected pre-exercise, and at 10 and 60 min following a maximal exercise test (VO2MAX). Breath VOCs were analysed by thermal desorption-gas chromatography-mass spectrometry using a non-targeted approach. Data showed a tendency for reduced isoprene in samples at 10 min post-exercise, with a return to baseline by 60 min. However, inter-individual variation meant differences between baseline and 10 min could not be confirmed, although the 10 and 60 min timepoints were different (p = 0.041). In addition, baseline samples showed a tendency for both acetone and isoprene to be reduced in those with higher absolute VO2MAX scores (mL(O2)/min), although with restricted statistical power. Baseline samples could not differentiate between relative VO2MAX scores (mL(O2)/kg/min). In conclusion, these data support that isoprene levels are dynamic in response to exercise.

A headspace collection chamber for whole body volatilomics

“…For instance, Brady et al assessed the attraction of mosquitoes to different human hosts over a 10 weeks period, demonstrating that variation of CO 2 production between different human participants may be a major chemical factor driving differential attractiveness. 63 Other areas of interest for the study of exhaled CO 2 include exercise monitoring, 64–66 the development of chemical sensors to detect trapped humans in search and rescue operations, 25,67 and the monitoring of human contributions to indoor air contaminants. 68…”

A headspace collection chamber for whole body volatilomics

“…For instance, Brady et al assessed the attraction of mosquitoes to different human hosts over a 10 week period, demonstrating that variation of CO2 production between different human participants may be a major chemical factor driving differential attractiveness. 63 Other areas of interest for the study of exhaled CO2 include exercise monitoring, [64][65][66] the development of chemical sensors to detect trapped humans in search and rescue operations, 25,67 and the monitoring of human contributions to indoor air contaminants. 68 In this study, the concentration of CO2 in the sampling chamber was recorded at 5-minute intervals throughout the 30-minute sampling period.…”

Stubborn Exercise Responders–Where to Next?

“…The results indicated baseline samples of acetone and isoprene are reduced in participants with higher absolute . VO 2max scores, and demonstrating dynamic isoprene concentration changes in response to exercise [50].…”

“…Exhaled volatile organic compounds change in response to low-intense exercise; however, this appears to lack application in exercise and sport [49]. A recent pilot study aimed to investigate the impact of maximal exercise to exhaustion on exhaled volatile organic compounds [50]. The results indicated baseline samples of acetone and isoprene are reduced in participants with higher absolute .…”