Another idea to try, wd - I always feel like I retain more fluid for a few days after returning to lower elevations. I know that the tendency when getting to higher elevations is to be dehydrated, so maybe I'm just extrapolating, but how about trying things that tend to have a diuretic effect (sudafed, tea/coffee, grapefruit, melons - these are what I've read, anyway - etc. as well as generally low sodium intake for a few days)?

I usually feel energized the first day I'm back from a high-altitude trip myself, though not on my most recent trip...maybe because I had too many undone things waiting for me, hmmm? <img src="/forums/images/graemlins/tongue.gif" alt="" />

I think the air is definitely cleaner up there, so allergies could also be the reason. I am always struck by the fact that my skin gets much clearer up there (no wayward zits like I usually have) even though I am not as clean in general.