AUTHOR=Opialla Tobias , Gollasch Benjamin , Kuich Peter H. J. L. , Klug Lars , Rahn Gabriele , Busjahn Andreas , Spuler Simone , Boschmann Michael , Kirwan Jennifer A. , Luft Friedrich C. , Kempa Stefan
TITLE=Exercise blood-drop metabolic profiling links metabolism with perceived exertion
JOURNAL=Frontiers in Molecular Biosciences
VOLUME=9
YEAR=2022
URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2022.1042231
DOI=10.3389/fmolb.2022.1042231
ISSN=2296-889X
ABSTRACT=Background: Assessing detailed metabolism in exercising persons minute-to-minute has not been possible. We developed a “drop-of-blood” platform to fulfill that need. Our study aimed not only to demonstrate the utility of our methodology, but also to give insights into unknown mechanisms and new directions.
Methods: We developed a platform, based on gas chromatography and mass spectrometry, to assess metabolism from a blood-drop. We first observed a single volunteer who ran 13 km in 61 min. We particularly monitored relative perceived exertion (RPE). We observed that 2,3-bisphosphoglycerate peaked at RPE in this subject. We next expanded these findings to women and men volunteers who performed an RPE-based exercise protocol to RPE at Fi O 2 20.9% or Fi O 2 14.5% in random order.
Results: At 6 km, our subject reached his maximum relative perceived exertion (RPE); however, he continued running, felt better, and finished his run. Lactate levels had stably increased by 2 km, ketoacids increased gradually until the run’s end, while the hypoxia marker, 2,3 bisphosphoglycerate, peaked at maximum relative perceived exertion. In our normal volunteers, the changes in lactate, pyruvate, ß hydroxybutyrate and a hydroxybutyrate were not identical, but similar to our model proband runner.
Conclusion: Glucose availability was not the limiting factor, as glucose availability increased towards exercise end in highly exerted subjects. Instead, the tricarboxylic acid→oxphos pathway, lactate clearance, and thus and the oxidative capacity appeared to be the defining elements in confronting maximal exertion. These ideas must be tested further in more definitive studies. Our preliminary work suggests that our single-drop methodology could be of great utility in studying exercise physiology.