If I hike 10 strenuous miles today, and get a liver panel in 2 days, will the hike by itself increase liver enzymes?

Possibly. I did a little research and was surprised to find that strenuous exercise can elevate liver enzymes, and they can remain elevated for up to a week. See: http://www.Ncbi.Nlm.Nih.Gov/pmc/articles/pmc2291230/. There are many other possible causes of elevated liver enzymes, so if this doesn't resolve with a week of rest, i would pursue further testing.