Oh, wow, I had the exact same experience (about elevated AST, ALT, not the car accident). It's got nothing to do with protein shakes, it happens when you start

Oh, wow, I had the exact same experience (about elevated AST, ALT, not the car accident). It's got nothing to do with protein shakes, it happens when you start working out after a long break. I went for my regular checkups and my AST ALT levels were through the roof (3-4 times the max value). The doctor ordered a few more tests, an ultrasound etc. I was very shocked, because my levels were perfectly normal a year before that, and I had not had any major lifestyle change. I went on an extensive search and finally concluded something similar—when you start working out after a long break, the breakdown in your skeletal muscles causes ALT ALT to be released into the blood, and it remains there for 1-2 weeks. In this process I also learned that the AST / ALT ratio is diagnostic. Depending on the ratio, it could be cirrhosis, or acute hepatitis, or fatty liver etc. My ratios were consistent with the working out after a long gap scenario, further increasing my confidence. Note that this does not happen once you work out regularly, it only happens when you start working out after a long gap. I told this to the doctor and linked him to the papers. He didn't outright say No but his response made it look like he didn't take my suggestion seriously. I guess he was bothered that I was playing "Youtube doctor", but well. I said I would like to confirm my theory by not working out for 2 weeks and then re-doing the tests. He also added a few more liver function tests to get more data. Everything turned out perfectly normal.