Thesis
Metabolomic Insights into Female Energetics: Analysing Substrate Utilisation Pathways in Eumenorrheic and Oral Contraceptive-Using Female Athletes
Murdoch University
Masters by Research, Murdoch University
2025
DOI:
https://doi.org/10.60867/00000057
Abstract
BACKGROUND: During exercise, the availability and utilisation of substrates (e.g., carbohydrates, fats, and amino acids), can significantly influence exercise performance. Multiple reports highlight changes in substrate utilisation associated with high-hormonal phases within eumenorrheic and oral contraceptive (OC) using females. The majority of these findings rely on indirect measures of metabolism (e.g., V̇O2 and blood lactate), providing limited insight into the mechanistic processes which contribute to substrate selection. The purpose of this thesis was to examine the impact of the high-hormone phase of the menstrual cycle (MC) and OC cycle, on key energetic pathways of substrate utilisation in female athletes at rest. To do so, we developed a novel metabolomic method, to quantify metabolites associated with the major pathways of substrate utilisation. METHODS: Plasma samples from eumenorrheic (n = 7) and OC-using (n = 5) female athletes, were examined using a combination of liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy techniques. Targeted analytes associated with the tricarboxylic (TCA) cycle (citric, succinic, fumaric, malic and -ketoglutaric acid); glycolysis (pyruvic and lactic acid); lipolysis (long chain fatty acids, medium chain acylcarnitines and long chain acylcarnitines); amino acid oxidation (leucine, isoleucine, and valine) were quantified. RESULTS: Amongst TCA-related analytes, citric and fumaric acid levels were significantly higher within the MC group compared to the OC group (p = 0.048, 95% CI [0.203, 0.919]; p = 0.030, 95% CI [0.322, 0.937]). No significant differences were observed in any of the substrate-related metabolites, suggesting that the differences in TCA analytes, were likely not substrate-driven. CONCLUSION: This data does not support differences in substrate utilisation, as previously noted during the high-hormone phase of MC and OC cycles. Importantly, the analytical methods developed for this study provide a minimally invasive technique for future research focused on human substrate utilisation.
Details
- Title
- Metabolomic Insights into Female Energetics: Analysing Substrate Utilisation Pathways in Eumenorrheic and Oral Contraceptive-Using Female Athletes
- Authors/Creators
- Jen McGlynn
- Contributors
- Nathan Lawler (Supervisor) - Murdoch University, Health Futures InstituteJeremiah Peiffer (Supervisor) - Murdoch University, School of Allied HealthNicola Gray Dr (Supervisor) - Murdoch University, Centre for Computational and Systems Medicine
- Awarding Institution
- Murdoch University; Masters by Research
- Publisher
- Murdoch University
- Identifiers
- 991005852086307891
- Murdoch Affiliation
- School of Medical, Molecular and Forensic Sciences
- Resource Type
- Thesis
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