IF YOU BODYBUILD...
THEN YOUR AST AND ALT MAY BE HIGH
Normal range: 10 to 40 units/ litre for AST; 9 to 46 units/litre for ALT
Normal change with
exercise: Up to double the high end of normal levels
What they are: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are generally called liver enzymes. High levels can signal liver disease such as hepatitis. Who’s at risk: Bodybuilders Why they rise: These enzymes aren’t just in your liver. Smaller amounts, especially of AST, are also in your muscles, says Dr. Nadolsky. So when they break down due to exercise, you may see a spike. Levels have been shown to return to the pre-exercise baseline within 24 hours.
What to do: Red-blood-cells’ lifespans are about 120 days, so a recheck after a couple weeks off isn’t likely to make a difference, says Dr. Waite. Either stop running or drop to a very low-intensity level for a month or more to see if it declines.
When to worry: Levels more than two times the upper limit are unlikely to stem from exercise, says Dr. Waite. That can indicate liver disease, especially if you also have abdominal pain, digestive difficulties, or yellowing skin.