Excessive exercise can induce metabolic disturbances that precede overt clinical disease. As the central metabolic organ, the liver plays a pivotal role in systemic metabolic adaptations to exercise, although its dynamic metabolic response remains poorly characterized. Characterizing hepatic metabolic shifts could advance early diagnostic and preventive strategies. Single exhaustive exercise (SEE) is an acute, short-duration, high exercise load, often used to model a single bout of supra-physiological exertion, whereas repeated exhaustive exercise (REE) models the cumulative physiological stress induced by consecutive exhaustive exercise sessions. This study systematically delineates temporal metabolic alterations in murine liver following SEE and REE. C57BL/6J mice were subjected to a single bout of exhaustive exercise or daily REE regimens for 7 consecutive days. Liver tissues and serum samples were collected at predetermined intervals (0, 1, 6, 12, 24, 48 h post-exercise) for comprehensive analysis, including untargeted metabolomics, histopathological evaluation, and quantification of liver injury biomarkers. SEE provoked transient metabolic perturbations that resolved within 24 h, whereas REE induced progressive metabolic remodeling, particularly involving amino acid metabolism. Both exercise modalities caused histologically confirmed hepatic injury, and the biomarkers for liver injury were elevated at an early stage but recovered within 24 h. Multivariate analysis identified "steroid hormone biosynthesis" and "taurine/hypotaurine metabolism" as key modules correlating with injury severity. Time-series analysis showed that most injury-related metabolites in the SEE group returned to baseline, whereas those in the REE group remained elevated through 48 h, suggesting sustained metabolic alterations within the observation window, which may reflect delayed recovery and/or adaptive metabolic remodeling in response to repeated exhaustive exercise. Our findings reveal distinct patterns of hepatic metabolic alteration: acute exhaustive exercise triggers self-limited metabolic adjustments, whereas repeated exhaustive exercise induces more sustained metabolic remodeling. These results underscore the importance of personalized exercise regimens and suggest that modulation of specific metabolic pathways may represent a potential strategy for mitigating exercise-induced hepatic stress.
Yang et al. (Mon,) studied this question.