Which markers indicate muscle breakdown?

Markers that indicate muscle breakdown include:

1. AST (Aspartate Aminotransferase) and ALT (Alanine Aminotransferase): These enzymes are essential biomarkers of muscle damage. An elevated AST to ALT ratio, specifically above 1, signals potential muscle damage. An AST to ALT ratio of approximately 1.67 implicates a significant risk of muscle damage.

2. Creatine Kinase (CK): This enzyme, particularly elevated after intense physical activities, is a crucial marker for muscle breakdown. Its levels can significantly increase even after a single bout of strenuous exercise, signaling muscle stress or damage.

3. Myoglobin: Released from muscle tissue into the bloodstream during muscle breakdown, myoglobin serves as another key indicator of muscle damage.

These markers can be especially relevant in clinical settings like rhabdomyolysis (often noted by dark urine from severe muscle breakdown) and for athletes monitoring recovery and training impact 1 2.