Unlocking Muscle Fatigue: Insights from Multi-Parametric 1H, 23Na & 31P MRI in Exercise-Induced Muscle Damage and Inflammation

Motivation: Exercise Induced Muscle Damage (EIMD) presents as a viable model to study the muscle inflammation and fatigue which may present across various age-related pathologies. Goal(s): Our model presents as a useful tool to test therapies aimed at improved patient rehabilitation. Approach: Here we use multi-parametric 31P, 23Na and 1H based MRI to show EMID is charactered by reduced muscle oxygenation with an increase in phosphate metabolism, sodium perturbation and overall perception of effort. Interestingly the cardiovascular response to exercise remained unchanged. Results: Our results suggest a discrepancy between cardiovascular and muscle metabolic demand leads to altered oxygen delivery during exercise and increased fatigability. Impact: This study highlights the importance of an integrative multi-parametric MRI approach to study the physiological consequences underlying muscle inflammation. This is crucial for advance our understanding on the abnormal responses present in age-related/health conditions characterised by muscle weakness and fatigue.