Liver panel
AST
Also called Aspartate aminotransferase · measured in U/L
What it measures
An enzyme found in liver and also in muscle and heart tissue.
Why it is tracked
Read alongside ALT. Because AST is present in muscle, strenuous exercise can raise it without any liver involvement — a common source of confusion in fit patients.
What a provider considers
- Raised by muscle damage as well as liver disease
- The AST/ALT ratio helps distinguish causes
- Recent heavy training can elevate it
Reference ranges vary between laboratories and a single result rarely means much on its own. Interpretation depends on your symptoms, your other markers and the trend over time — which is what your provider reviews.